Findings of an Extraluminal Leiomyosarcoma of the Urinary Bladder in a Dog.

A 9 yr old male miniature poodle presented with acute diarrhea, vomiting, and a distended abdomen. A large and firm mass was palpated in the caudal abdomen. Radiography showed a large soft-tissue mass in the mid ventral abdomen. The mass was mildly contrast-enhancing and in contact with the right cranial aspect of the bladder on computed tomography. The mass was heterogeneous with minimal blood flow on Doppler examination. Surgery confirmed its origin of the urinary bladder, and it was diagnosed leiomyosarcoma on pathology. This is the first report of extraluminal leiomyosarcoma of the bladder wall with imaging characteristics using various modalities.

Subcutaneous leiomyosarcoma in a cynomolgus macaque (Macaca fascicularis).

Leiomyosarcoma, a malignant tumour originating from smooth muscle cells, has rarely been documented in non-human primates. In this case study, a 7-year-old female cynomolgus macaque (Macaca fascicularis) presented with a rapidly growing mass overlying the left elbow joint. Radiographs indicated the presence of a soft tissue neoplasm without any associated bone involvement. The mass was surgically resected. Histological and immunohistochemical analyses revealed spindle-shaped cells with eosinophilic cytoplasm that resembled smooth muscle cells, exhibiting positive immunoreactions for vimentin, desmin and smooth muscle actin and a negative reaction for pan-cytokeratin. This is the first reported case of subcutaneous leiomyosarcoma in a cynomolgus macaque and provides important insights into the incidence and characteristics of this condition in this species.

First report of primary testicular leiomyosarcoma in two dogs.

BACKGROUND: Testicular tumours are common in dogs and, among them, interstitial cell tumours, seminomas and sustentacular cell tumours are the most reported. Mesenchymal testicular tumours are rarely reported in humans as in veterinary medicine where only three cases of sarcomas (leiomyomas and leomyosarcomas) have been described in two stallions and in a ram. CASE PRESENTATION: The present cases regarded a 12-year-old mixed-breed dog and a 10-year-old American Staffordshire Terrier that underwent bilateral orchiectomy. Formalin fixed testes were referred for histopathological diagnosis. At gross examination, in one of the testes of both dogs, a white, firm and variably cystic testicular mass, effacing and replacing the testicular parenchyma was detected. Samples were collected from both neoplastic and contralateral testes, routinely processed for histology and serial sections were also examined immunohistochemically with primary antibodies against cytokeratins, vimentin, Von Willebrand factor, inhibin-α, α-smooth muscle actin, smooth muscle myosin and desmin. Histopathological features as well as the immunohistochemical results, positive for vimentin, actin, myosin and desmin, confirmed the mesenchymal origin and the myoid phenotype of both testicular tumours supporting the diagnoses of leiomyosarcoma. CONCLUSIONS: To the authors knowledge these are the first cases of primary testicular sarcoma reported in the canine species. However, even rare, these tumours deserve to be considered in routine diagnosis when a testicular spindle cell tumour is observed. The immunohistochemical panel applied was useful to distinguish the present tumours from undifferentiated Sertoli cell tumours confirming the diagnosis of leiomyosarcoma.

A rare case of primary hepatic poorly differentiated leiomyosarcoma in a goat.

A 12-year-old Saanen goat presented with a history of hyporexia and sudden recumbency. Euthanasia was indicated due to suspicion of hepatic neoplasia associated with senility. Necropsy revealed generalized oedema and increased liver size and weight (33 × 38 × 17 cm and 10.6 kg, respectively), with a firm, multilobular mass. Fusiform to polygonal neoplastic cells, with marked pleomorphism, anisocytosis and anisokaryosis, were seen on histopathological examination of the hepatic mass. The neoplastic cells were immunohistochemically positive for alpha-smooth muscle actin and vimentin but immunonegative for pancytokeratin. The Ki-67 index was 18.8%. A poorly differentiated leiomyosarcoma was diagnosed on the basis of the gross, histopathological and immunohistochemical findings and should be included in the differential diagnosis of liver disease in goats.

CT features of gastrointestinal spindle cell, epithelial, and round cell tumors in 41 dogs.

There is sparse published information on computed tomographic (CT) characteristics of canine gastrointestinal tumors. The purposes of this multi-center, retrospective, descriptive study were to describe the CT features of histologically-confirmed canine gastrointestinal spindle cell, epithelial, and round cell tumors and, when available, describe the corresponding ultrasound findings. The inclusion criteria were as follows: availability of pre-and post-contrast CT study, and a histopathological diagnosis of the lesions. Recorded parameters were tumor size, location, gastrointestinal wall layers involvement, lesion's growth and enhancement patterns, tumor margination, presence of stenosis, mineralization, ulcerations, lymphadenopathy, or other lesions in the abdomen/thorax. When available, ultrasound images were evaluated. Forty-one dogs met the inclusion criteria and had the following histological diagnoses: 21/41 (51%) spindle cells (7 leiomyomas, 14 leiomyosarcomas/gastrointestinal stromal tumors (GISTs)), 13/41 (32%) epithelial (adenocarcinoma), and 7/41 (17%) round cell (lymphoma) tumors. The growth pattern was concentric, eccentric, and mixed in epithelial, spindle cell, and round cell tumors, respectively. Spindle cell tumors had the largest main volume and involved the outer gastrointestinal layer with an unaffected inner layer. Leiomyosarcomas/GISTs showed irregular margins compared to leiomyomas. Only lymphomas showed multifocal gastrointestinal involvement. Nine carcinomas and six spindle cell tumors caused partial stenosis with secondary sub-obstruction. Mineralizations were more frequent in spindle cell tumors (10/21) and absent in lymphomas. Lymphadenomegaly was widespread in lymphomas, regional in leiomyosarcomas-GISTs and adenocarcinomas, and absent in leiomyomas. The reported CT features may be useful in prioritizing the differential diagnosis between spindle cell, epithelial, and round cell tumors, similar to those reported on ultrasound.

CT features of malignant tubular genital tract tumors in seven goats.

Neoplasia of the tubular genital tract in goats, while rarely described, is most commonly reported as uterine adenocarcinoma, leiomyoma, or leiomyosarcoma. In this retrospective, single-center, case series, medical records were searched for goats with a computed tomography (CT) diagnosis of tubular genital mass and a definitive histologic (surgical biopsy or necropsy) diagnosis of malignant neoplasia. Data recorded from CT images were presence of peritoneal/retroperitoneal fluid, urinary tract obstruction, abdominal lymphadenomegaly, additional abdominal nodules/masses, and pulmonary nodules. For masses, maximum cross-sectional area, contrast enhancement, and uterine luminal fluid accumulation were also recorded. Seven goats met the inclusion criteria (leiomyosarcoma n = 5, adenocarcinoma n = 2). Both goats with adenocarcinoma had upper urinary tract obstruction, moderate to severe regional lymphadenopathy, peritoneal fluid, and peritoneal or hepatic nodules/masses; one goat with adenocarcinoma was discharged and subsequently euthanized, and the other had palliative mass debulking and was lost to follow up. Goats with leiomyosarcoma had infrequent, mild peritoneal fluid and mild sublumbar lymphadenopathy. Of the goats with leiomyosarcoma, two were euthanized at or near the time of CT imaging, two were euthanized at the time of surgery due to perceived mass non-resectability, and one had mass regression approximately four months post ovariohysterectomy but was subsequently lost to follow up. Five goats had pulmonary nodules, three of which had pathologic confirmation (pulmonary metastasis in a single patient with adenocarcinoma, and lungworm granulomas in two goats with leiomyosarcoma). Severe sublumbar lymphadenopathy and obstructive uropathy were sequelae in the two caprine patients with genital adenocarcinoma, and in none with leiomyosarcoma.

Glucoregulatory factors in canine hepatocellular carcinoma and leiomyosarcoma with non-islet cell tumour hypoglycaemia.

INTRODUCTION: Hypoglycaemia caused by malignant tumours other than insulinoma is referred to as non-islet cell tumour hypoglycaemia (NICTH), which may be caused by hepatocellular carcinoma (HCC) and leiomyosarcoma (LMS) in veterinary medicine. However, the pathogenetic mechanism of NICTH remains unclear. Therefore, this study aimed to evaluate the gene-expression levels of glucoregulatory factors in canine HCC and LMS accompanied by hypoglycaemia. MATERIALS & METHODS: Four patients (three with HCC and one with LMS) exhibiting hypoglycemia were included in the hypoglycemic (H) group, whereas ten patients not exhibiting hypoglycemia were in the non-hypoglycaemia (NH) group. The preoperative and postoperative blood glucose and serum insulin-like growth factor-2 (IGF-2) levels, as well as the expression of genes involved regulating blood glucose levels were analysed. RESULTS: Compared with the NH group, the H group exhibited significantly decreased blood-glucose levels, which increased to normal values after surgery. Compared with the NH group, the H group exhibited significantly increased gene expression of insulin-like growth factor 1, IGF-2, and insulin-like growth factor binding protein 3 in the tumours. Conversely, expression of genes encoding glucoregulatory factors including insulin, gastric inhibitory polypeptide and glucagon was not observed. Serum IGF-2 levels were significantly higher in the H group compared with that in the control group (healthy dogs) and NH group. In two cases in the H group, serum IGF-2 levels decreased after tumour resection. CONCLUSION: These results suggest that NICTH development in dogs with HCC and LMS is mechanistically associated with IGF-2 overexpression and elevated serum IGF-2 levels.

Feline uterine carcinosarcoma infiltrated with osteoclast-like giant cells.

A 12-year-old female Himalayan cat underwent an ovariohysterectomy to remove an intra-abdominal mass. Histologic examination using immunohistochemical staining revealed that the mass was comprised of epithelial and mesenchymal components. Within the lesion, multinucleated giant cells (MGCs) were observed diffusely. MGCs were positive for vimentin and Iba-1 and negative for cytokeratin AE1/AE3 and CD204. In addition, MGCs were negative for Ki-67, indicating nonneoplastic cells. Osteoclast-like MGC (OLMGC) phenotype with tartrate-resistant acid phosphatase positivity was also seen. These findings suggested that the uterine tumor was carcinosarcoma with OLMGCs. Uterine tumors in humans, such as leiomyosarcoma and carcinosarcoma, with OLMGC infiltration, are well-known pathologic entities; however, they are rare in animals and to our knowledge, have not been previously reported in cats.

Computed tomography and magnetic resonance imaging findings in dogs with vaginal leiomyoma and leiomyosarcoma.

BACKGROUND: In humans, magnetic resonance imaging (MRI) is preferred over computed tomography (CT) for the assessment of pelvic lesions. Although CT findings of several pelvic tumours have been reported in veterinary medicine, MRI findings are limited. OBJECTIVES: The purpose of this study was to retrospectively compare the CT and MRI findings in dogs with vaginal leiomyoma and leiomyosarcoma. METHODS: This retrospective study of five dogs compared the CT and MRI findings of intrapelvic lesions, including vaginal leiomyoma (n = 4) and leiomyosarcoma (n = 1). No invasion of the surrounding tissue was detected on histopathological examination. In this retrospective study, the following parameters of CT and MRI were recorded for each dog: the border between the lesion and the adjacent pelvic organs, including the prostate, rectum or urethra; signal intensity (SI) of the lesion; enhancement pattern; presence of haemorrhage; necrosis or cystic areas and lymphadenopathy. Because SI on MRI is affected by cell density, tumour cell density was analysed using a microscope slide. RESULTS: In vaginal leiomyoma, the border between the lesion and the surrounding pelvic organ tends to be clearer on MRI than on CT. In vaginal leiomyosarcoma, the border was comparable between MRI and CT. Each lesion showed heterogeneous enhancement on CT and MRI scans. In each lesion, the assessment of haemorrhage, necrosis, cystic areas and lymphadenopathy was comparable between MRI and CT. The SI of the lesion on T2WI of the vaginal leiomyoma and leiomyosarcoma were hyperintense in four cases (4/4; 100%) and mixed intense in one case (1/1; 100%), respectively. The cell density of leiomyosarcoma is higher than that of leiomyomas. CONCLUSIONS: The SI on T2WI may be useful for differentiating leiomyoma from leiomyosarcoma. MRI may be useful to differentiate vaginal leiomyomas from leiomyosarcomas and evaluate margins.

Presumptive metastatic leiomyosarcoma in a feedlot steer.

A 14-month-old feedlot steer was depressed and died while being examined. The gross post-mortem examination of the steer conducted at the feedlot identified numerous masses within the abdomen and thorax, including a large mass in the liver that eroded into the vena cava. Many masses in the lungs appeared to be the result of hematogenous distribution. Histologic examination of the masses confirmed the presence of neoplasia. Although the histologic appearance of the neoplasms was not typical of well-differentiated leiomyosarcoma, immunohistochemical staining supported that diagnosis. Leiomyosarcomas are rare among North American cattle. In this case, the primary neoplasm appears to have originated in the wall of the vena cava within the liver. Key clinical message: This report adds to the limited information on leiomyosarcomas in cattle, while highlighting both the challenges faced by veterinarians conducting post-mortem examinations on large animals in below freezing temperatures, as well as the current methods available to arrive at a diagnosis of a rare disease.

Léiomyosarcome métastatique présumé chez un bouvillon de parc d'engraissement. Un bouvillon de parc d'engraissement âgé de 14 mois était abattu et est mort pendant son examen. L'examen macroscopique du bouvillon réalisée au parc d'engraissement a identifié de nombreuses masses dans l'abdomen et le thorax, y compris une grosse masse dans le foie qui s'est étendue dans la veine cave. De nombreuses masses dans les poumons semblaient être le résultat d'une distribution hématogène. L'examen histologique des masses a confirmé la présence d'un néoplasme. Bien que l'aspect histologique du néoplasme ne soit pas typique d'un léiomyosarcome bien différencié, la coloration immunohistochimique a corroboré ce diagnostic. Les léiomyosarcomes sont rares chez les bovins nord-américains. Dans ce cas, le néoplasme primaire semble provenir de la paroi de la veine cave dans le foie.Message clinique clé :Ce rapport s'ajoute aux informations limitées sur les léiomyosarcomes chez les bovins, tout en soulignant à la fois les défis auxquels sont confrontés les vétérinaires effectuant des examens post-mortem sur de grands animaux à des températures inférieures au point de congélation, ainsi que les méthodes actuelles disponibles pour arriver à un diagnostic d'une maladie rare.(Traduit par Dr Serge Messier).

Leiomyosarcoma with widespread metastases in a capybara.

A 10.5-y-old intact female capybara (Hydrochoerus hydrochaeris) with a history of chronic weight loss was euthanized following discovery by palpation of a large intra-abdominal mass. Postmortem examination revealed a large, firm, tan mass expanding the uterine body and extensively adhered to the jejunum and abdominal wall. Numerous pinpoint to 3-cm diameter, tan-to-red, raised masses were present throughout the parietal peritoneum, liver, lungs, and intestinal serosa. Histologic examination of the uterine mass revealed well-differentiated smooth muscle intermixed with abundant collagen, interspersed with a highly anaplastic spindle cell population extending to the serosa; the masses in the lung, liver, and peritoneum were histologically very similar to the anaplastic uterine spindle cells. Immunohistochemical staining of the uterus and lung confirmed smooth muscle origin of the anaplastic cells. To our knowledge, leiomyosarcoma has not been reported previously in a capybara, and the widespread metastases in this case represent an unusually aggressive presentation of this rare malignancy. The animal also had an incidental dermal histiocytoma, a tumor that has also not been reported previously in this species, to our knowledge.

Leiomyosarcoma of urinary bladder in a Shih Tzu dog.

A 10-year-old intact male Shih Tzu dog presented with hematuria. Double-contrast cystography revealed a polypoid filling defect at the apex of the urinary bladder. Ultrasonography revealed a heterogeneously hypoechoic intramural mass with minimal vascular flow beneath the submucosal layer. After partial cystectomy, a well-demarcated bladder leiomyosarcoma was diagnosed on histopathology. The patient was alive and well without any clinical signs, recurrence, or metastasis at the 29-month follow-up after the surgical removal of the bladder mass. Leiomyosarcoma should be considered as a differential diagnosis if mass-like lesions are observed in the urinary bladder, although this type of malignancy is rare in canines. Histopathological confirmation is important for predicting prognosis and determining further medical plans.

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.

Retrospective immunohistochemical investigation of suspected non-visceral leiomyosarcoma in dogs.

Visceral leiomyosarcoma is well described in dogs, but information about non-visceral locations and prevalence is lacking. The diagnosis of leiomyosarcoma is challenging without a gold standard, and often includes the use of immunohistochemical (IHC) stains. We used defined histopathologic patterns, histochemical staining, and IHC staining for smooth muscle actin (SMA), desmin, and laminin to characterize suspected non-visceral leiomyosarcoma in dogs at a single academic institution. In a retrospective search, we identified 24 dogs with a definitive or suspected histologic diagnosis of leiomyosarcoma in a non-visceral location. Histopathology results and clinical details were obtained. Biopsy sections were reviewed by a single pathologist using standardized histologic criteria, including light microscopic appearance, immunohistochemistry (more than two-thirds of neoplastic cells labeled with SMA and desmin or laminin), and histochemical staining (minimal-to-mild matrix deposition by Masson trichrome). Of the 24 cases of possible non-visceral leiomyosarcomas, 4 were consistent with a definitive diagnosis of non-visceral leiomyosarcoma (3) or leiomyoma (1) based on the established criteria. Only the leiomyoma had more than two-thirds of neoplastic cells label with all 3 markers; all 3 leiomyosarcomas had more than two-thirds of neoplastic cells label with SMA and laminin. Our data highlight the uncommon nature of non-visceral leiomyosarcoma and the importance of IHC for their diagnosis. A definitive diagnosis could not be made based on SMA alone, and desmin was not useful in this cohort. Further studies are needed to clarify the histopathologic, IHC, and clinical features of canine non-visceral SMA-positive mesenchymal tumors.

Canine smooth muscle tumors: A clinicopathological study.

Canine smooth muscle tumors (SMTs) commonly develop in the alimentary and female genital tracts and less frequently in soft tissue. The definition of histological criteria of malignancy is less detailed for SMTs in dogs than in humans. This study evaluated the clinicopathologic features of canine SMTs and compared the veterinary and human medical criteria of malignancy. A total of 105 canine SMTs were evaluated histologically and classified according to both veterinary and human criteria. The Ki67 labeling index was assessed in all SMTs. Estrogen receptor (ER) and progesterone receptor (PR) expression was evaluated for soft tissue SMTs. Follow-up data were available in 25 cases. SMTs were diagnosed in the female genital tract (42%), alimentary tract (22%), and soft tissue (20%). Soft tissue SMTs frequently arose in the perigenital area, pelvic cavity, and retroperitoneum. A subset of soft tissue SMTs expressed ER and/or PR, resembling the gynecologic type of soft tissue SMT in humans. SMTs were less frequently malignant when assessed with human criteria than with veterinary criteria, better reflecting their benign behavior, especially in the genital tract where human criteria tolerate a higher mitotic count for leiomyoma. Decreased differentiation was correlated with increased proliferation, necrosis, and reduced desmin expression. Mitotic count, Ki67 labeling index, and necrosis were correlated with metastases and tumor-related death. Further prognostic studies are warranted to confirm the better performance of the human criteria when assessing SMT malignancy, especially genital cases, to confirm their usefulness in ER/PR-expressing soft tissue SMTs, and to better define the most useful prognostic parameters for canine SMTs.

Surgical treatment of uterine neoplasia in 13 production size pigs with a comparison to pot-bellied pigs.

OBJECTIVES: The primary objective of this study was to describe the clinical management and surgical treatment of production size pigs (PrdP) with uterine neoplasia. A secondary objective was to compare tumor diagnoses as well as short- and long-term survival between PrdP and a published report of pot-bellied pigs (PBP) following surgical intervention. STUDY DESIGN: Retrospective clinical study. ANIMALS OR SAMPLE POPULATION: Client-owned PrdP (n = 13) treated with exploratory celiotomy ±ovariohysterectomy for uterine neoplasia. METHODS: Medical records from a university hospital were reviewed for historical treatment, presenting complaint, clinical signs, diagnostics, surgical intervention, pathology, and outcome. An online owner survey was performed for follow-up. The novel PrdP cohort was compared to a previously published PBP cohort for differences in tumor diagnoses, surgical complications, and survival. Descriptive statistics, Fischer's exact tests and odds ratios were reported. RESULTS: PrdP were affected by uterine leiomyoma (4/11), leiomyosarcoma (2/11), adenoma (1/11), adenocarcinoma (3/11), and carcinosarcoma (1/11) with no difference in tumor types between PrdP and PBP. PrdP surviving to hospital discharge (6/13) survived at least 1 year postoperatively, with median follow-up of 16 months (14-60 months). PrdP were less likely than PBP to survive in the short-term despite similar frequencies of marked intraoperative hemorrhage. PrdP and PBP had comparable rates of long-term survival following hospital discharge. CONCLUSION: PrdP are afflicted by similar uterine neoplasia diagnoses as PBP, but they have lower rates of short-term survival to hospital discharge with surgical treatment. CLINICAL SIGNIFICANCE/IMPACT: PrdP have a guarded prognosis for survival to hospital discharge when operated for uterine neoplasia.

Invasive leiomyosarcoma involving the tongue of an Arabian mare.

A 10 year-old endurance Arabian mare was presented with an invasive, firm, multilobulated mass at the left ventral face of the tongue. The mare had a history of four months of ptyalism, dysphagia, severe halitosis, and dysmastication. The Evaluation of the horse included physical and oral examination, complete blood count and serum biochemistry profile, computed tomography evaluation of the head, and histopathology of the mass. The computerized tomography (CT) head scan showed the homogeneous mass in the oral cavity confirming the degree of invasion on the tongue, as well as a small mineral focus at the left dorsal mandibular border and increased density of the submandibular lymph nodes. At necropsy, gross findings in the oral cavity revealed an irregular, nodular and partially ulcerated mass at the level of the body of the tongue in the ventral aspect, with a size of approximately 10 × 15 × 8 cm. Histologically, the tongue revealed a neoplastic process of mesenchymal muscle origin. The tumor cells showed distinctive morphological and architectural patterns in some areas. An immunohistochemistry panel was done yielding a positive reaction for Calponin and Desmin, confirming diagnostics of as a soft tissue leiomyosarcoma in the tongue. Immunohistochemistry results, in combination with histopathologic morphology, were suggestive of a leiomyosarcoma originating in the perivascular wall tissue. Oral leiomyosarcoma are very rare in veterinary medicine, and to the authors' knowledge, this is the first case report to utilize histopathology, immunohistochemistry and imaginology to describe oral leiomyosarcoma in a horse.

Outcome, prognostic factors and histological characterization of canine gastrointestinal sarcomas.

Canine gastrointestinal sarcomas, a group of tumours that includes leiomyosarcomas (LMSAs), gastrointestinal stromal tumours (GISTs) and other rarer sarcomas, comprise about 10-30% of all gastrointestinal tumours. This study aims to characterize the histologic characteristics and clinical behaviour in order to identify prognostic factors predictive of outcome. A single institution database search for surgically treated gastrointestinal sarcomas yielded 47 cases with adequate tissue remaining for histologic analysis and 42 cases available for analysis of clinical outcome. Tumours were then prospectively evaluated for mitotic count, necrosis, haemorrhage and inflammation, as well as categorized via immunohistochemical (IHC) staining for smooth muscle actin, c-KIT and DOG-1. IHC analysis defined 32 tumours as GISTs, 14 as LMSAs and one as a sarcoma not otherwise specified. For both GISTs and LMSAs, the overall median survival time (MST) is 1024 days (range 31-1456), which did not differ statistically between tumour types (p = .92). The overall metastatic rate of GISTs in this study was 32.1% (n = 9) which was not significantly different to that of LMSAs at 15.3% (n = 2, p = .45). In multivariate analysis, mitotic count under 9 in GIST patients and complete surgical excision in all tumour types correlated with improved MST. For patients with GISTs, the intensity of c-KIT staining also correlated positively with survival, with an MST of 250 days in cases with weak staining and an MST of 1418 days in cases with moderate or strong c-KIT staining (p = .005).

Prostatic leiomyosarcoma in a dog treated using a multimodal approach.

Prostatic leiomyosarcoma is an uncommon tumor encountered in male dogs, with only 2 cases reported in the veterinary literature with no follow-up described. A 12-year-old male intact German Wirehaired Pointer presented for evaluation of straining to defecate and urinate. Whole body computed tomography (CT) examination identified a spherical multicavitary expansile mass arising from the prostate gland and severely obliterating the pelvic canal. Partial subcapsular prostatectomy was performed, and histological and immunohistochemical results were consistent with prostatic leiomyosarcoma. Metronomic cyclophosphamide and nonsteroidal anti-inflammatory drugs were administered as adjuvant chemotherapy. Follow-up CT 10 months later indicated no signs of recurrence or metastasis. To the best of our knowledge, this patient represents the first report of successful multidisciplinary treatment consisting of partial subcapsular prostatectomy and adjuvant chemotherapy for prostatic leiomyosarcoma in a dog. After 15 months of follow-up, the patient remained recurrence-free without metastasis.

Intestinal Myxoid Leiomyosarcoma in a Sambar Deer (Rusa unicolor).

A 9-year-old male sambar deer (Rusa unicolor) that died during sedation had a large and firm polypoid mass, which expanded the small intestinal wall and partially obstructed the duodenal lumen. Histopathology revealed a pleomorphic sarcoma composed of stellate to spindloid cells loosely arranged in an abundant myxoid matrix. The cytoplasm of the neoplastic cells was strongly immunopositive for vimentin and smooth muscle actin, but negative for c-KIT, desmin and myoglobin. The findings are consistent with intestinal myxoid leiomyosarcoma, which is rare in cervids and has not been described in the sambar deer, which is an endangered species.