Undifferentiated pleomorphic sarcoma in a white-eared opossum (Didelphisalbiventris).

We report a case of high-grade undifferentiated pleomorphic sarcoma in a free-living white-eared opossum (Didelphis albiventris) in Central Brazil. Grossly, it appeared as a soft yellow mass, approximately 8 cm in diameter, with an irregular, adherent and ulcerated surface, which extended from the proximal epiphysis of the femur to the proximal third of the tibia and fibula. The mass invaded the medullary cavity and had a necrotic centre. Multiple nodular metastases (0.5-1.5 cm) were present in the liver, lungs and spleen. Histologically, the neoplasm was characterized by pleomorphic cells with indistinct boundaries, many multinucleated cells, necrosis and tissue invasion. There was intense cytoplasmic immunolabelling of neoplastic cells for vimentin and moderate cytoplasmic and nuclear labelling for human muscle actin, human smooth muscle actin and lysozyme. Immunolabelling for Iba1, CD18, CD1A, cytokeratin AE1/AE3, glial fibrillary acidic protein and desmin was negative. To our knowledge, this is the first report of an undifferentiated pleomorphic sarcoma in this species.

Narrative operative reports inconsistently record surgical information relating to resection of soft tissue sarcomas and mast cell tumors in dogs.

OBJECTIVE: To report to what degree narrative operative reports for soft tissue sarcoma (STS) and mast cell tumor (MCT) resections met a predetermined template made up of essential elements. ANIMALS: 197 consecutive client-owned animals between May 1, 2017, and August 1, 2022. PROCEDURES: A consensus list of 9 elements made up the final synoptic operative report (SR) template. Consecutive narrative surgery reports (NRs) of dogs that underwent MCT or STS resection were then reviewed to determine how many of the SR elements were present in each NR. A score was then determined for each NR out of a maximum total of 9. RESULTS: Overall, 197 reports (99 MCT and 98 STS) were included. The median score was 5 (56% of elements reported). No report had all 9 elements, and 1 report had none of the elements reported. When MCT and STS were analyzed independently, the median score was 6 (67% of elements reported) for MCT and 5 (56% of elements reported) for STS. There was a trend of more cases with MCT that had a preoperative diagnosis, intraoperative measurements of the tumor, and surgeon margins marked compared to dogs with STS. More dogs with STS had an estimated Enneking dose compared to dogs with MCT. CLINICAL RELEVANCE: Our data show that essential elements of STS and MCT resection in dogs were inconsistently recorded and no case had all elements present. This mirrors data in people and presses the need for more standardization in reporting of cancer operations in veterinary medicine.

Grade shifts in recurrent canine soft tissue sarcomas and mast cell tumors.

OBJECTIVE: To determine the incidence of histologic grade shift (alteration of grade relative to the original tumor) in recurrent canine soft tissue sarcoma (STS) and mast cell tumor (MCT), and to determine the level of agreement between blinded pathologist review and original histology interpretation of STS and MCT grades. ANIMALS: 15 dogs with recurrent cutaneous/subcutaneous STS and 5 dogs with recurrent cutaneous MCT. All included dogs underwent excision of both the primary and recurrent tumors and had tumor samples available for review. PROCEDURES: The medical records and histology database from a single institution were reviewed, and data were recorded and analyzed. A single board-certified veterinary pathologist performed blinded evaluation of all excisional tumor samples, including both primary and recurrent disease, and these were evaluated independently and in conjunction with initial pathologic diagnoses. RESULTS: Based on single pathologist review, 7 of 15 (46.7%) dogs with recurrent STS had grade shift characterized by a higher or lower recurrent tumor grade in 4 of 7 and 3 of 7 cases, respectively, and 1 of 5 dogs with recurrent MCT had grade shift characterized by an increased grade of the recurrent tumor. Variability in reported grade between original histology report and pathologist review occurred for 13 of 30 (43.3%) STS excisional biopsy samples and 0 of 10 MCT excisional biopsy samples. CLINICAL RELEVANCE: Grade shift has been reported in multiple tumor types in people and has the potential to alter prognosis and treatment recommendations. This is the first study to document this phenomenon in dogs. Additional large-scale studies are needed to determine factors associated with grade shift as well as prognostic significance of grade shift for recurrent canine STS and MCT.

Nasal leiomyosarcoma in a Quarter Horse / Leiomiossarcoma nasal em equino Quarto de Milha

We described the clinical and anatomopathological findings observed in a case of nasal leiomyosarcoma in a five-year-old male Quarter Mile horse, whose main complaints were decreased sports performance and bilateral purulent nasal discharge. The nodule was observed in the nasal cavity, obstructing the left nostril and associated with purulent drainage. The nodule was of irregular shape and yellow color, measuring 19.4 cm × 6.9 cm × 4.3 cm in size, with coalescent multifocal areas that were brownish, friable, opaque, and fetid. When cut, the surface was compact, grayish-white, and smooth with yellow, friable, irregular multifocal areas, measuring 1-3.2 cm in diameter. Histopathological examination showed spindle-shaped neoplastic cells, which was negative on Masson's trichromic stain. A diagnosis of leiomyosarcoma was established based on the morphotintorial aspects of neoplastic cells and confirmed through immunohistochemistry, with positive immunostaining for antibodies 1A4, HHF35, desmin, and S100. Leiomyosarcoma primarily affects the nasal cavity of horses and should be included in the differential diagnosis of diseases that affect the nasal cavity and cause nasal obstruction associated with dyspnea.

Descreve-se os achados clínicos e anatomopatológicos observados em um caso de leiomiossarcoma nasal em um equino, Quarto de Milha, macho, de cinco anos de idade, com queixa principal de diminuição do rendimento esportivo e secreção nasal purulenta bilateral. Na cavidade nasal, observou-se um nódulo obstruindo a narina esquerda associada à secreção purulenta. O nódulo era de superfície irregular, amarelada, brilhante, fibroelástica, medindo 19,4 x 6,9 x 4,3cm de tamanho, com áreas multifocais a coalescente acastanhadas, friáveis, opacas e fétidas. Ao corte, a superfície era compacta, branco-acinzentada e lisa com áreas multifocais amarelas, friáveis e irregulares, medindo 1-3,2 cm de diâmetro. No exame histopatológico foi observado proliferação de células neoplásicas fusiformes, que foram negativas na coloração de Tricrômico de Masson. O diagnóstico de leiomiossarcoma foi estabelecido com base nos aspectos morfotintoriais das células neoplásicas e confirmado através da imuno-histoquímica, no qual houve imunomarcação positiva para os anticorpos 1A4, HHF35, Desmina e S100. O leiomiossarcoma pode afetar primariamente a cavidade nasal de equinos, devendo ser incluído no diagnóstico diferencial de doenças que afetam a cavidade nasal e que provocam quadros de obstrução nasal associado a dispneia.

Immunolabelling of Acetylated Histones 3 and 4 and Histone Deacetylases 1, 2 and 6 in Canine Soft Tissue Sarcomas.

The objective of this study was to investigate the immunolabelling of acetylated histones and histone desacetylase (HDAC) enzymes in canine soft tissue sarcomas (STSs) and to correlate them with histological and clinical features in order to identify possible prognostic and therapeutic targets in these neoplasms. Fifteen canine STS samples were evaluated and were submitted to immunohistochemistry for acetylated histones 3 (H3) and 4 (H4) and deacetylating enzymes (HDAC1, HDAC2 and HDAC6). Intense immunolabelling of H4 was seen in comparison with H3. A strong positive correlation was observed between the H3 intensity score and the number of mitotic figures (P = 0.004, r = 0.7). Intense immunolabelling of HDAC1 was found in comparison to the expression of HDAC2 and HDAC6 in the evaluated STSs. This finding suggests that HDAC1 may be a potential target for HDAC inhibitors in STSs in dogs.

Duodenal leiomyosarcoma in a cat: Cytologic, pathologic, and immunohistochemical findings.

A 7-year-old mixed-breed neutered male cat was presented with a history of chronic vomiting with increased frequency in the last month, progressing to depression and profuse projectile vomiting. Abdominal ultrasonography revealed an area of marked segmental duodenal thickening associated with a nodule, and euthanasia was performed due to a poor prognosis. Grossly, at the postmortem examination, the wall of a duodenal segment was severely expanded by a nodule measuring 5.0 cm in diameter, resulting in marked luminal narrowing and obstruction. Smears were made by scraping the cut surface of the tumor during the postmortem examination. The smears were highly cellular and contained mesenchymal cells arranged individually or in large non-cohesive aggregates. Cells varied in morphology from spindle to round to stellate-shaped with marked anisocytosis and anisokaryosis. Numerous bi- and multinucleated neoplastic cells were observed. Histologic examination revealed a densely cellular neoplastic proliferation of mesenchymal cells that effaced the duodenal submucosa, muscularis externa, and serosa layers. Most cells were spindle-shaped; however, some tumor areas had numerous round cells and bi- and multinucleated neoplastic cells. Spindle cells showed variable cytoplasmic immunoreactivity for vimentin, smooth muscle actin, and desmin. Round, bi-, and multinucleated giant cells only had marked multifocal cytoplasmic immunoreactivity for vimentin. Neoplastic cells did not have immunoreactivity for cytokeratin, GFAP, S100, and CD117. A final diagnosis of duodenal leiomyosarcoma was made. This article reports the pathologic, cytologic, and immunohistochemical findings of this case and discusses the main differential diagnoses in cases of intestinal sarcomas in domestic animals.

Local tumour response to neoadjuvant therapy with 2-aminoethyl dihydrogen phosphate in dogs with soft tissue sarcoma.

BACKGROUND: In cases of soft tissue sarcoma (STS), neoadjuvant therapy is indicated to downstage the tumour prior to surgery to achieve enhanced local tumour control. The antineoplastic phospholipid compound 2-aminoethyl dihydrogen phosphate (2-AEH2F) is an alkyl phosphate ester capable of inhibiting cell proliferation and inducing cell death by modifying the asymmetry of phospholipids in the cytoplasmic membrane OBJECTIVES: This clinical study was designed to investigate local antitumoural effects of neoadjuvant therapy with 2-AEH2F in dogs with naturally occurring STS MATERIAL AND METHODS: Dogs (n = 11) received four consecutive weekly intravenous injections of 2-AEH2F (70 mg/kg) prior to tumour resection. Tomographic (CT) and thermal (TE) images were used to investigate changes in tumour size and local temperature in response to treatment RESULTS: Comparative analysis of CT images (n = 9/11) failed to reveal complete or partial remission according to selected assessment criteria (RECIST, WHO and volumetric). Comparative analysis of TE images (n = 10/11) revealed significantly (p = 0.01416) lower temperatures in tumoural areas relative to surrounding tissues over the course of treatment CONCLUSIONS: 2-AEH2F had no cytoreductive effects when used at doses and intervals described in this study. However, significant drop in skin temperatures recorded in tumoural areas suggest induction of physiological changes.

Histomorphological and immunophenotypic characterizationof feline injection site-associated sarcoma

Background: Feline Injection Site-Associated Sarcoma (FISS) is a mesenchymal neoplasia of aggressive behavior thatdevelops in sites where vaccine or drugs were administered. FISS is clinically characterized by the appearance of asolitary firm nodule or a diffuse mass, adhered to tissues, in regions associated to vaccine or drug applications. Despitelow prevalence, tumor recurrence rates can reach 80%. FISS present more aggressive histological characteristics whencompared to sarcomas not associated to injection sites. The aim of this paper is to contribute towards the understandingof the biological behavior of FISS.Materials, Methods & Results: Sixteen samples of FISS were analyzed. Fibrosarcomas were the most frequent histological subtype (62.5%). Malignant peripheral nerve sheath tumor was diagnosed in 18.75% cases. Ten (62.5%) FISS wereclassified as grade II; 4/16 (25%) grade I, and 2/16 (12.5%) grade III. Cox-2 overexpression occurred in 3/16 (18.75%)samples, with positive correlation between Cox-2 expression and cellularity (r = 0.696, P = 0.003). Mitotic index lowerthan 9 events was found in 11/16 (68.7%) samples and between 10 and 19 mitotic events in 5/16 (31.3%) cases. MeanKi-67 expression was 2.39 ± 2.48%. FISS characterized as fibrosarcomas presented longer overall survival (median 545days) than other histological subtypes (median 130.5 days) [P = 0.01].Discussion: Patients with FISS generally present with larger nodules than those with sarcomas not associated to injections,suggesting a challenge for pet owners to note subcutaneous tumors in the interscapular region, in addition to the aggressivebiological behavior of FISS. The influence of size on prognosis remains controversial. An association between histologicgrade and the development of metastasis has been observed, with patients with grade III FISS associated with an increasein the metastatic rate. The present study did not find a correlation between overall survival...(AU)

Thermographic assessment of skin and soft tissue tumors in cats.

OBJECTIVES: This study set out to determine the average temperature of skin and soft tissue tumors in cats using infrared thermography and to investigate correlations between thermographic findings and tumor type. Correlations between thermographic findings, histologic subtype and tumor grade were also investigated in cases of feline injection site sarcoma (FISS). METHODS: Thermographic images of normal skin and skin overlying neoplastic lesions were prospectively obtained. Following thermographic assessment, tumors were resected and submitted to histopathologic and immunohistochemical analysis. Mean temperatures detected in tumoral areas were compared between different tumor types and between FISSs of different histologic subtypes and grades. RESULTS: Thermograms obtained from 11 healthy cats and 31 cats presenting with skin and soft tissue tumors (eight benign and 23 malignant tumors, including 21 FISSs) were evaluated in this study. Thermal behavior varied widely in normal skin, as well as in skin overlying neoplastic lesions. Mean temperatures were significantly higher in malignant compared with benign tumors (35.4 ± 1.8ºC and 34.5 ± 1.7ºC respectively; P = 0.01), with a temperature above 34.7ºC being associated with malignancy (sensitivity 76%, specificity 80%; P = 0.01). Temperatures detected in FISS did not differ significantly according to histologic subtype (P = 0.91) or tumor grade (P = 0.46), or between primary and recurring tumors (P = 0.25). CONCLUSIONS AND RELEVANCE: Infrared thermography proved to be a sensitive and effective method for detection of temperature differences between malignant and benign skin and soft tissue tumors in cats. Thermographic assessment may contribute to diagnosis and prognostic estimation in feline oncologic patients.

Feline giant-cell pleomorphic sarcoma: cytologic, histologic and immunohistochemical characterization.

OBJECTIVES: This study aimed to characterize the cytologic, pathologic and immunohistochemical (IHC) aspects of feline giant-cell sarcoma. METHODS: Biopsy and necropsy reports from the Department of Veterinary Pathology were retrieved, and 13 cases of pleomorphic sarcoma (PS) were selected according to the established epidemiologic, pathologic and IHC criteria. All samples were fixed in 10% formalin, routinely processed for histology, and stained with hematoxylin and eosin. Samples also underwent IHC testing for vimentin, ionized calcium-binding adaptor molecule 1 (Iba-1), desmin, actin and S-100. RESULTS: The mean age of the affected cats was 9.5 years, and females were over-represented. Most neoplasms were observed in the flank, lateral thorax, limbs and interscapular region, and were >2 cm in diameter. Cytology analysis revealed highly cellular preparations with three distinct populations (spindle cells, small round cells and multinucleated giant cells) in a dense eosinophilic stroma. Histologically, PS was composed of a combination of these three populations. IHC labeling for vimentin and Iba-1 was strongly positive for spindle cells and multinucleated giant cells, respectively. Desmin/actin showed variable labeling among the samples. S-100 was negative in all samples. CONCLUSIONS AND RELEVANCE: PS is a neoplasm of mesenchymal origin, also known as malignant fibrous histiocytoma. The predominant subtype in this study that affected the cats was the giant-cell type, characterized by the presence of multinucleated giant cells among spindle-shaped cells. These findings are similar to those described in human patients; thus, a comparison between the neoplasms seen in these species might be useful, and the knowledge of biologic behavior and overall treatment approach for humans could be extrapolated to cats.

Hormone receptor expression, clinical and histopathological analysis in feline injection site sarcomas.

Feline injection site sarcomas (FISS) are aggressive, with high recurrence and rarely metastasising. The objective of this study was to evaluate, by immunohistochemistry, the expression of oestrogen (ER) and progesterone (PR) receptors in FISS and correlate them with clinical and histopathological aspects. This was a retrospective study with 51 cases of FISS. Immunohistochemistry was performed to detect vimentin, ER, PR and Ki67 expression. Clinical, histopathological and immunohistochemical characteristics were predictor variables and the expression of ER and PR were the dependent ones. Twenty-eight (55%) of the 51 FISS cases were female and 23 (45%) male with 10.7 ± 4.2 years and median tumour size of 3 cm (2.0-5.4). The trunk was the most affected site, with 38 cases (84%). Histological grade III was observed in 57% of the cases, considering differentiation score, necrosis and mitotic index. ER expression, positive in 64% of cases, was associated with the mitotic index (P = .05) and degree of pleomorphism (P = .04). PR was not associated with the variables and 63% of cases were negative for this receptor. Thus, ER expression can affect tumour growth. The knowledge on the FISS hormonal expression is important to clarify the pathophysiological mechanisms. Further studies are needed to predict the value of ER expression in the prognosis of FISS.

Histomorphological and immunophenotypic characterizationof feline injection site-associated sarcoma

Background: Feline Injection Site-Associated Sarcoma (FISS) is a mesenchymal neoplasia of aggressive behavior thatdevelops in sites where vaccine or drugs were administered. FISS is clinically characterized by the appearance of asolitary firm nodule or a diffuse mass, adhered to tissues, in regions associated to vaccine or drug applications. Despitelow prevalence, tumor recurrence rates can reach 80%. FISS present more aggressive histological characteristics whencompared to sarcomas not associated to injection sites. The aim of this paper is to contribute towards the understandingof the biological behavior of FISS.Materials, Methods & Results: Sixteen samples of FISS were analyzed. Fibrosarcomas were the most frequent histological subtype (62.5%). Malignant peripheral nerve sheath tumor was diagnosed in 18.75% cases. Ten (62.5%) FISS wereclassified as grade II; 4/16 (25%) grade I, and 2/16 (12.5%) grade III. Cox-2 overexpression occurred in 3/16 (18.75%)samples, with positive correlation between Cox-2 expression and cellularity (r = 0.696, P = 0.003). Mitotic index lowerthan 9 events was found in 11/16 (68.7%) samples and between 10 and 19 mitotic events in 5/16 (31.3%) cases. MeanKi-67 expression was 2.39 ± 2.48%. FISS characterized as fibrosarcomas presented longer overall survival (median 545days) than other histological subtypes (median 130.5 days) [P = 0.01].Discussion: Patients with FISS generally present with larger nodules than those with sarcomas not associated to injections,suggesting a challenge for pet owners to note subcutaneous tumors in the interscapular region, in addition to the aggressivebiological behavior of FISS. The influence of size on prognosis remains controversial. An association between histologicgrade and the development of metastasis has been observed, with patients with grade III FISS associated with an increasein the metastatic rate. The present study did not find a correlation between overall survival...

Sarcoma estromal esplênico em canino da raça labrador / Splenic stromal sarcoma in a labrador dog

Background: Splenic stromal neoplasms are a heterogeneous group of tumors that shares the morphology of spindle cells, and are considered a primary mesenchymal neoplasm of the spleen. Among these neoplasms, some are as yet unclassified. Although stromal neoplasms represent 25 a 50% of dog splenic neoplasms in dogs, subtypes rarely occur alone. As these neoplasms are difficult to diagnose in the routine veterinary medical examination, the objective of this article was to report a case of splenic stromal sarcoma in a dog treated at a private veterinary hospital in Recife, Pernambuco, Brazil. Case: An 8-year-old male labrador dog was treated at a veterinary hospital for an initial clinical suspicion of gastroenteritis. Clinical examinations showed anemic ocular mucosa and a distended abdomen. Considering the animal's condition, blood count, serum biochemistry, and abdominal ultrasonography (US) were requested. The laboratory tests revealed anemia, thrombocytopenia, leukocytosis with neutrophilia, and changes in the indices of alanine aminotransferase (ALT) and alkaline phosphatase (ALP), among other findings. Abdominal ultrasound showed hepatomegaly, diffuse splenomegaly, a neoformation in the spleen suggestive of splenic neoplasia, and mild cystic prostatic hyperplasia. The dog underwent exploratory laparotomy with splenectomy. During the procedure, a nodule was found attached to the spleen. It was removed, fixed in a 10% neutral buffered formalin solution, and sent for histopathological and immunohistochemical examinations (vimentin, S100, desmin, MyoD1, HHF35, CD31, and alpha smooth muscle actin). The histopathological diagnosis was poorly differentiated spindle cell splenic sarcoma, compatible with splenic stromal sarcoma. Immunohistochemistry showed neoplastic cells immunoreactive for vimentin and S100, and it was not reactive for other markers. Based on the immunohistochemical and morphological profile, the diagnosis of splenic stromal sarcoma was confirmed. Discussion: Dogs affected by splenic neoplasms are generally aged between three and 17 years, and clinically present with anorexia, emesis, lethargy, weight loss, and abdomen distension, which were observed in the present case. However, a purelyclinical diagnosis is disputable, since other diseases can present the same signs. Thus, complementary exams are essential for a correct diagnosis. Laboratory changes in blood count and serum biochemistry are considered nonspecific for splenic neoplasms, with neutrophilic leukocytosis and anemia being consistent with paraneoplastic syndromes frequently diagnosed in small animals. Microscopically, splenic stromal sarcomas are characterized by focal splenic nodules composed of cohesive polygonal to spindle-shaped cell layers. The cells usually exhibit anisokaryosis and often have large oval to round vesicular nuclei and, occasionally, multinucleated cells. They have large areas of necrosis, diffuse or nodular lymphoid aggregates, and foci of extramedullary hematopoiesis, consistent with the histopathological examination reported in the present case. The immunohistochemical analysis included evaluation of seven markers to elucidate the histogenesis of the neoplasm, with the anti-vimentin and anti-S100 markers demonstrating positive cytoplasmic immunoreactivity, revealing the mesenchymal origin of the neoplasm. Thus, the definitive diagnosis was splenic stromal sarcoma, a rare and aggressive neoplasm.

Sarcoma de sítio de aplicação em felinos / Feline injection-site sarcoma

Sarcomas de sítio de aplicação são neoplasias malignas de origem mesenquimal caracterizadas pelo comportamento biológico agressivo. Apesar da extensa pesquisa, a patogênese da doença ainda não está totalmente esclarecida, acredita-se que a administração de vacinas, medicamentos e outros injetáveis no tecido subcutâneo ou intramuscular em gatos predispostos, possa induzir uma reação inflamatória crônica e, posteriormente, a transformação neoplásica. O diagnóstico é realizado por meio da biópsia, porém deve ser feito avaliação da extensão do tumor primário, o estadiamento padrão e a avaliação geral da saúde desses pacientes. A abordagem terapêutica multimodal, associando a excisão cirúrgica radical à radioterapia, quimioterapia ou imunoterapia, tem demonstrado melhores resultados. A escolha do local de injeção, frequência de vacinação e recomendações para reduzir a reação inflamatória são considerações importantes para a prevenção. O objetivo desta revisão é fornecer uma visão geral do atual conhecimento sobre sarcoma de sítio de aplicação em felinos.

Injection-site sarcomas are malignant neoplasms whose mesenchymal origin is characterized by aggressive biological behavior, developing from various tissues, being fibrosarcoma the most common histological type in felines. Despite wide research, the pathogenesis of the disease is still not fully understood, the most accepted hypothesis suggests that administration of vaccines, medications and other injectables into the subcutaneous or intramuscular tissue of predisposed cats may induce a chronic inflammatory reaction and, subsequently, neoplastic transformation. Related to epidemiology, it presents low prevalence and high rates of regress even after aggressive treatments. The diagnosis is performed through biopsy and histopathological examination, assessmentof the extent of the primary tumor, the standard staging and general evaluation of the health of these patients. The multimodal therapeutic approach, associating radical surgical excision with radiotherapy, chemotherapy or immunotherapy, has shown better results. Choosing the injection site, frequency of vaccination and recommendations to reduce the inflammatory reaction are important considerations for prevention. The aim of this review is to provide an overview of the current knowledge on feline application site sarcoma.

Sarcoma de sítio de aplicação em felinos / Feline injection-site sarcoma

Sarcomas de sítio de aplicação são neoplasias malignas de origem mesenquimal caracterizadas pelo comportamento biológico agressivo. Apesar da extensa pesquisa, a patogênese da doença ainda não está totalmente esclarecida, acredita-se que a administração de vacinas, medicamentos e outros injetáveis no tecido subcutâneo ou intramuscular em gatos predispostos, possa induzir uma reação inflamatória crônica e, posteriormente, a transformação neoplásica. O diagnóstico é realizado por meio da biópsia, porém deve ser feito avaliação da extensão do tumor primário, o estadiamento padrão e a avaliação geral da saúde desses pacientes. A abordagem terapêutica multimodal, associando a excisão cirúrgica radical à radioterapia, quimioterapia ou imunoterapia, tem demonstrado melhores resultados. A escolha do local de injeção, frequência de vacinação e recomendações para reduzir a reação inflamatória são considerações importantes para a prevenção. O objetivo desta revisão é fornecer uma visão geral do atual conhecimento sobre sarcoma de sítio de aplicação em felinos.(AU)

Injection-site sarcomas are malignant neoplasms whose mesenchymal origin is characterized by aggressive biological behavior, developing from various tissues, being fibrosarcoma the most common histological type in felines. Despite wide research, the pathogenesis of the disease is still not fully understood, the most accepted hypothesis suggests that administration of vaccines, medications and other injectables into the subcutaneous or intramuscular tissue of predisposed cats may induce a chronic inflammatory reaction and, subsequently, neoplastic transformation. Related to epidemiology, it presents low prevalence and high rates of regress even after aggressive treatments. The diagnosis is performed through biopsy and histopathological examination, assessmentof the extent of the primary tumor, the standard staging and general evaluation of the health of these patients. The multimodal therapeutic approach, associating radical surgical excision with radiotherapy, chemotherapy or immunotherapy, has shown better results. Choosing the injection site, frequency of vaccination and recommendations to reduce the inflammatory reaction are important considerations for prevention. The aim of this review is to provide an overview of the current knowledge on feline application site sarcoma.(AU)

Histopathology and immunohistochemistry of peripheral neural sheath tumor and perivascular wall tumor in dog / Histopatologia e imuno-histoquímica de tumor de bainha de nervo periférico e de tumor de parede perivascular em cães

Soft tissue sarcomas (STS) comprise a heterogeneous group of malignancies derived from extra-skeletal mesenchymal tissues that may show similar histopathological changes. Histopathologic patterns suggestive of perivascular wall tumors (PWT) and peripheral nerve sheath tumors (PNST) have been described. This study investigated the histogenesis in a series of 71 cases of canine STS that showed morphological compatibility with what is described for PWT and PNST. Immunohistochemistry analysis were done to CD56, S100, SMA, Desmin, Von Willebrand Factor, NSE and GFAP. Twenty-one cases (29.6%) showed histopathologic features compatible with PWT, 23 cases (32.4%) with PNST and 27 cases (38.0%) shared both histopathological features. By immunohistochemistry, 59 (83.1%) cases showed positivity only for neural markers and 12 (16.9%) had simultaneous positivity for both neural and muscle markers. PNST was the most prevalent neoplasm and none of the cases were positive for muscle markers only. The histopathologic features were not useful to define the diagnosis of PWT, since most tumors were negative for muscle markers but positive for neural markers. Due to this immunoreactivity and the morphologic features, future studies may propose guidelines for the classification of these neoplasms.(AU)

Sarcoma de tecidos moles (STM) compreende um grupo heterogêneo de neoplasias malignas, derivadas de tecidos extraesqueléticos, que podem apresentar alterações histopatológicas similares. Os padrões histopatológicos sugestivos de tumor de parede perivascular (TPP) e de tumor de bainha de nervo periférico (TBNP) têm sido descritos. Este estudo investigou a histogênese de uma série de 71 STM caninos, que apresentavam compatibilidade morfológica com o que é descrito para TPP e TBNP. A análise imuno-histoquímica foi feita para CD56, S100, SMA, Desmina, Fator Von Willebrand, NSE e GFAP. Vinte e um casos (29,6%) apresentaram características histopatológicas compatíveis com TPP, 23 casos (32,4%) com TBNP e 27 casos (38,0%) apresentaram características histopatológicas de ambos. Na imuno-histoquímica, 59 (83,1%) casos apresentaram positividade somente para marcadores neurais e 12 (16,9%) tiveram positividade simultânea tanto para marcadores neurais como para marcadores musculares. TBNP foi a neoplasia mais prevalente e nenhum dos casos foi positivo para somente para marcadores musculares. As características histopatológicas não foram úteis para definir o diagnóstico de TPP, uma vez que a maioria foi negativa para marcadores musculares, mas positiva para marcadores neurais. Devido a essa imunorreatividade e às características morfológicas, pesquisas futuras poderão propor orientações para a classificação dessas neoplasias.(AU)

Neuropathic pain and prognosis of a dog submitted to limb amputation after diagnosis of soft tissue sarcoma - case report / Dor neuropática e prognóstico de um cão submetido à amputação de membro após diagnóstico de sarcoma de tecidos moles - relato de caso

Neuropathic pain occurs when there is a lesion or a dysfunction of the nervous system. Humans and veterinary patients may develop neuropathic pain, but in veterinary it is not often reported probably because of its mistaken diagnosis. A canine patient was admitted to the Veterinary Hospital of UNESP-Jaboticabal-SP, Brazil with a nodule on the left thoracic limb. The nodule was surgically removed, and histopathological analysis demonstrated the tumor was a soft tissue sarcoma (STS) and the margins were not clean. Based on the patient's health condition and the lack of suitable equipment, the next procedure was limb amputation. The patient received analgesic medication in the post-surgery period; nevertheless, clinical signs of neuropathic pain were present, such as compulsive licking and other behavioral disorders. Medications were administered for forty days, but clinical signs ceased only when replaced with a tryciclic antidepressant drug, Amitriptyline. Therapeutic management of the patient in this report can be considered effective, since five years after the end of the treatment there was no recurrence or presence of metastasis.(AU)

A dor neuropática ocorre quando há uma lesão ou disfunção do sistema nervoso. Tanto pacientes humanos quanto veterinários podem desenvolver a dor neuropática, mas na medicina veterinária ela é pouco relatada provavelmente por não ser corretamente diagnosticada. Um paciente canino foi atendido no Hospital Veterinário da Unesp-Jaboticabal, SP, Brasil, com um nódulo em membro torácico esquerdo. O nódulo foi removido cirurgicamente, e o exame histopatológico evidenciou a presença de sarcoma de tecidos moles (STM) e de margens comprometidas. Baseando-se nas condições de saúde do paciente e na ausência de equipamentos adequados, o próximo procedimento foi a amputação do membro. No pós-cirúrgico, o animal recebeu medicações analgésicas, todavia, mesmo assim, apresentava sinais de dor neuropática, como lambedura compulsiva e outros distúrbios comportamentais. O tratamento para dor aguda se estendeu por 40 dias; no entanto, os sinais clínicos cessaram apenas quando os analgésicos comuns foram substituídos por um medicamento antidepressivo tricíclico, a amitriptilina. O manejo terapêutico do paciente do presente relato pode ser considerado satisfatório, uma vez que, após cinco anos do término do tratamento, não houve recidiva nem presença de metástase.(AU)

Neuropathic pain and prognosis of a dog submitted to limb amputation after diagnosis of soft tissue sarcoma - case report / Dor neuropática e prognóstico de um cão submetido à amputação de membro após diagnóstico de sarcoma de tecidos moles - relato de caso

Neuropathic pain occurs when there is a lesion or a dysfunction of the nervous system. Humans and veterinary patients may develop neuropathic pain, but in veterinary it is not often reported probably because of its mistaken diagnosis. A canine patient was admitted to the Veterinary Hospital of UNESP-Jaboticabal-SP, Brazil with a nodule on the left thoracic limb. The nodule was surgically removed, and histopathological analysis demonstrated the tumor was a soft tissue sarcoma (STS) and the margins were not clean. Based on the patient's health condition and the lack of suitable equipment, the next procedure was limb amputation. The patient received analgesic medication in the post-surgery period; nevertheless, clinical signs of neuropathic pain were present, such as compulsive licking and other behavioral disorders. Medications were administered for forty days, but clinical signs ceased only when replaced with a tryciclic antidepressant drug, Amitriptyline. Therapeutic management of the patient in this report can be considered effective, since five years after the end of the treatment there was no recurrence or presence of metastasis.(AU)

A dor neuropática ocorre quando há uma lesão ou disfunção do sistema nervoso. Tanto pacientes humanos quanto veterinários podem desenvolver a dor neuropática, mas na medicina veterinária ela é pouco relatada provavelmente por não ser corretamente diagnosticada. Um paciente canino foi atendido no Hospital Veterinário da Unesp-Jaboticabal, SP, Brasil, com um nódulo em membro torácico esquerdo. O nódulo foi removido cirurgicamente, e o exame histopatológico evidenciou a presença de sarcoma de tecidos moles (STM) e de margens comprometidas. Baseando-se nas condições de saúde do paciente e na ausência de equipamentos adequados, o próximo procedimento foi a amputação do membro. No pós-cirúrgico, o animal recebeu medicações analgésicas, todavia, mesmo assim, apresentava sinais de dor neuropática, como lambedura compulsiva e outros distúrbios comportamentais. O tratamento para dor aguda se estendeu por 40 dias; no entanto, os sinais clínicos cessaram apenas quando os analgésicos comuns foram substituídos por um medicamento antidepressivo tricíclico, a amitriptilina. O manejo terapêutico do paciente do presente relato pode ser considerado satisfatório, uma vez que, após cinco anos do término do tratamento, não houve recidiva nem presença de metástase.(AU)

Histopathology and immunohistochemistry of peripheral neural sheath tumor and perivascular wall tumor in dog / Histopatologia e imuno-histoquímica de tumor de bainha de nervo periférico e de tumor de parede perivascular em cães

Soft tissue sarcomas (STS) comprise a heterogeneous group of malignancies derived from extra-skeletal mesenchymal tissues that may show similar histopathological changes. Histopathologic patterns suggestive of perivascular wall tumors (PWT) and peripheral nerve sheath tumors (PNST) have been described. This study investigated the histogenesis in a series of 71 cases of canine STS that showed morphological compatibility with what is described for PWT and PNST. Immunohistochemistry analysis were done to CD56, S100, SMA, Desmin, Von Willebrand Factor, NSE and GFAP. Twenty-one cases (29.6%) showed histopathologic features compatible with PWT, 23 cases (32.4%) with PNST and 27 cases (38.0%) shared both histopathological features. By immunohistochemistry, 59 (83.1%) cases showed positivity only for neural markers and 12 (16.9%) had simultaneous positivity for both neural and muscle markers. PNST was the most prevalent neoplasm and none of the cases were positive for muscle markers only. The histopathologic features were not useful to define the diagnosis of PWT, since most tumors were negative for muscle markers but positive for neural markers. Due to this immunoreactivity and the morphologic features, future studies may propose guidelines for the classification of these neoplasms.(AU)

Sarcoma de tecidos moles (STM) compreende um grupo heterogêneo de neoplasias malignas, derivadas de tecidos extraesqueléticos, que podem apresentar alterações histopatológicas similares. Os padrões histopatológicos sugestivos de tumor de parede perivascular (TPP) e de tumor de bainha de nervo periférico (TBNP) têm sido descritos. Este estudo investigou a histogênese de uma série de 71 STM caninos, que apresentavam compatibilidade morfológica com o que é descrito para TPP e TBNP. A análise imuno-histoquímica foi feita para CD56, S100, SMA, Desmina, Fator Von Willebrand, NSE e GFAP. Vinte e um casos (29,6%) apresentaram características histopatológicas compatíveis com TPP, 23 casos (32,4%) com TBNP e 27 casos (38,0%) apresentaram características histopatológicas de ambos. Na imuno-histoquímica, 59 (83,1%) casos apresentaram positividade somente para marcadores neurais e 12 (16,9%) tiveram positividade simultânea tanto para marcadores neurais como para marcadores musculares. TBNP foi a neoplasia mais prevalente e nenhum dos casos foi positivo para somente para marcadores musculares. As características histopatológicas não foram úteis para definir o diagnóstico de TPP, uma vez que a maioria foi negativa para marcadores musculares, mas positiva para marcadores neurais. Devido a essa imunorreatividade e às características morfológicas, pesquisas futuras poderão propor orientações para a classificação dessas neoplasias.(AU)

Sarcoma de tecidos moles em cães: a ressecção cirúrgica cura? / Soft tissue sarcomas in dogs: does surgical resection heal?

Os sarcomas de tecidos moles (STM) são um grupo de diferentes tipos de tumores de origem mesenquimal; descritos como massas pseu-doencapsuladas com margens mal definidas que apresentam índices altos de recidiva local em comparação ao baixo a moderado potencial metastático. Ocorrem tanto em seres humanos quanto em animais; compreendem aproximadamente 15% de todos os tumores de pele e de subcutâneo em cães. Devido ao seu comportamento invasivo, a remoção cirúrgica é o tratamento indicado para os cães acometidos por tais tumores, incluindo-se também a radioterapia após ressecção incompleta, pois o papel da quimioterapia ainda é pouco conhecido.

Soft tissue sarcomas (STS), a heterogeneous group of different tumors of mesenchymal origin, are described as pseudo-encapsulated masses with poor defined margins that present high rates of local recurrence compared to the low to moderate metastatic potential. They can occur both in humans and animals, and in dogs they comprise approximately 15% of all skin and subcutaneous tumors. Due to its invasive behavior, surgery is the main treatment applied for these tumors in dogs, and it can be combined to radiotherapy after the incomplete resection because the role of chemotherapy is still very poorly understood in this subject.