Early progression during or after cyclophosphamide, doxorubicin, vincristine, and prednisone chemotherapy indicates poor outcome with rescue protocols in dogs with multicentric lymphoma.

BACKGROUND: Dogs with lymphoma that fail cyclophosphamide, doxorubicin, vincristine, and prednisone chemotherapy (CHOP) before completion of their protocol are commonly thought to have poor long-term outcome, but no previous studies have evaluated the effect of early relapse on progression-free interval (PFI) or overall survival time (OST) for patients undergoing rescue chemotherapy. OBJECTIVE: Correlate rescue treatment outcomes in dogs with multicentric lymphoma with outcomes after 1st-line CHOP chemotherapy. METHODS: Data were collected from 6 previous retrospective or prospective studies in 187 dogs with multicentric lymphoma that received 1st-line CHOP chemotherapy and then received either lomustine (CCNU), L-asparaginase and prednisone (LAP), or rabacfosadine (RAB, Tanovea), with or without prednisone or L-asparaginase. RESULTS: The PFI after initiation of CHOP chemotherapy was significantly associated with response rate postprogression, PFI, and postrescue survival time (ST) for both rescue protocols. Immunophenotype (B- vs T-cell) was not significantly associated with response, PFI or OST for LAP but was significantly associated with response and PFI for RAB. CONCLUSION: Dogs that experience short PFI during or after 1st-line CHOP chemotherapy had lower response rates to rescue treatment, with shorter PFI and ST. Immunophenotype did not significantly affect outcome with LAP but was associated with PFI for RAB.

A case of equine multicentric lymphoma: Clinical, microscopical, and molecular findings.

Background: Although relatively uncommon, lymphoma is the most prevalent haematopoietic neoplasia in horses, and multicentric lymphoma remains the most common presentation of the disease. The pathogenesis of equine lymphoma is still poorly understood and the diagnosis is usually confirmed at an advanced stage of the disease, compromising the prognosis. This study investigated the clinical, pathological, and molecular features of a case of equine multicentric lymphoma. Case Description: An apparently healthy 5-year-old crossbreed mare hospitalized at the Centre of Animal Reproduction of Vairão, Portugal, suddenly presented clinical signs of supraorbital oedema and mandibular lymph node enlargement, developing fever, facial oedema, and generalized lymphadenopathy. The mare ended up dying twenty-four days after the first clinical signs due to multisystem organ failure. Haematological and biochemical analyses, necropsy, and microscopic and molecular evaluation of affected tissues were performed. At necropsy, the main findings were multiple multinodular lesions, distributed along the serous surface of oropharynx, trachea, pericardium, gastrointestinal tract, and mesentery. Microscopically, these consisted of solid proliferations of neoplastic round cells that exhibited immunopositivity for CD3 (T cells). Based on these findings, a medium-grade multicentric T-cell lymphoma was diagnosed. Conclusion: There is still very little research regarding the molecular characterization of lymphoma in horses. As an entity itself is quite heterogeneous, it is important to describe the interspecies particularities to understand its development and behaviour.

The diagnostic relevance of mesenteric lymph node biopsy in small intestinal lymphoma in cats.

BACKGROUND: Regional lymph nodes are frequently sampled in cats with suspected intestinal lymphoma; however, their diagnostic value has not been explored. OBJECTIVES: To investigate whether histologic and immunohistochemical analysis of mesenteric lymph nodes correlates with the diagnosis of intestinal lymphoma in cats. ANIMALS: One hundred 2 client-owned cats diagnosed with intestinal lymphoma. METHODS: Retrospective study. The inclusion criteria required a full-thickness biopsy of the small intestine and concurrent excision of mesenteric lymph nodes. Histologic and immunophenotypic analyses were performed on intestinal biopsies and corresponding lymph nodes. Selected nodal samples diagnosed with reactive lymph nodes underwent clonality testing. RESULTS: Transmural T-cell lymphomas, encompassing small and large cell types, were predominant (64 cases, 62.7%), with large B-cell lymphomas being more frequently transmural (68.8%) than mucosal (31.2%). Among all lymph nodes examined, 44 (43.1%; 95% CI: 33.9%-52.8%) exhibited neoplastic infiltration. Among cases of small cell lymphoma, 51 out of 72 (70.8%; 95% CI: 59.4%-80.1%) showed no nodal involvement. Clonality results correctly identified 19/30 (63.3%; 95% CI: 45.5%-78.2%) reactive lymph nodes. Concerns were raised regarding clonal identification in the remaining cases and potential misdiagnoses based on phenotypic characteristics. CONCLUSION AND CLINICAL IMPORTANCE: The study underscores the potential drawbacks of relying solely on mesenteric lymph nodes for diagnosing intestinal lymphomas in cats, particularly small cell subtypes. It emphasizes the importance of full-thickness biopsies for assessing transmural infiltration and recommends caution when utilizing mesenteric lymph nodes for histologic, immunohistochemical and clonality evaluations in mucosal lymphomas. Despite limitations, this research highlights the need for comprehensive diagnostic strategies in cats with intestinal lymphoma.

Efficacy and adverse events of L-Asparaginase administration as a first-line treatment for feline large-cell gastrointestinal lymphoma.

L-Asparaginase (L-Asp) is often used to induce remission in feline large-cell gastrointestinal lymphoma (LCGIL). However, no study has evaluated the efficacy and adverse events following the initial use of this drug as a first-line treatment in feline LCGIL. We retrospectively reviewed medical records of cats with LCGIL treated with L-Asp to induce remission. This study included 43 cats. The response rate (RR) after the first administration of L-Asp was 37.2% (Complete remission: 7.0%, partial remission: 30.2%). RR was significantly higher in cases with primary gastric lesions (64.3%) than in those with primary intestinal lesions (24.1%) (P=0.018), and it was also higher in cases without anemia (57.1%) than those with anemia (15.0%) (P=0.009). The most common adverse event was hyperammonemia, which occurred in 10 of 12 cases where we could compare plasma ammonia concentrations before and after the first dose of L-Asp. Plasma phosphate concentrations were also significantly increased (P<0.001) within 24 hr after the first dose. Decreased appetite, vomiting, and diarrhea were also observed in five, three, and seven cases, respectively, and Grade 3 or higher gastrointestinal signs were observed as adverse events in three cases. The median overall survival of all cats was 150 days (range, 5-1,065 days), and the median progression-free survival was 104 days (range, 2-978 days). In conclusion, L-Asp was effective to induce remission, and severe adverse events were uncommon in feline LCGIL.

THE MANAGEMENT OF LYMPHOPROLIFERATIVE NEOPLASIA IN FOUR NORTHERN SEA OTTERS (ENHYDRA LUTRIS KENYONI).

Lymphoproliferative neoplasia has been reported in both free-ranging sea otters and those in managed care, but little information is available on the management of this neoplastic disease in this species. This case series describes clinical lymphoma in four northern sea otters (Enhydra lutris kenyoni) in managed care. Two otters presented with Stage 5 lymphoma with evidence of hematologic spread resulting in leukemia. Two additional otters presented with Stage 3 disease. Immunophenotypes in these cases included disseminated large B-cell lymphoma and lymphoblastic lymphoma of potential T-cell origin. Cases were managed with multiagent chemotherapy protocols including prednisone, L-asparaginase, cyclophosphamide, vincristine, cytosine arabinoside, lomustine, and doxorubicin. Unique approaches included the use of a vascular access port in one case and development of an autologous vaccine in another. Survival time ranged from 81 to 409 days. Diagnosis, staging, and treatment with multiagent protocols is recommended for the management of lymphoma in sea otters.

Diagnosis of renal lymphoma by Wright-Giemsa-stained cytocentrifuged urine evaluation in a cat.

Lymphoma represents up to 30% of neoplasms diagnosed in cats. Diagnosis of lymphoma in the urinary system by examination of urine sediment has been described in a dog, but apparently not previously in cats. Concurrent samples of serum, EDTA whole blood, and urine were submitted from a 15-year-old spayed female domestic shorthair cat exhibiting weight loss, polyuria, and polydipsia. Hematology and biochemical abnormalities included a mild normocytic, normochromic, non-regenerative anemia; an inflammatory leukogram; and azotemia. Urinalysis evaluation revealed inadequate urine concentration and marked proteinuria. Wet-mount urine sediment examination revealed moderate numbers of leukocytes and erythrocytes. A uniform population of intermediate-to-large lymphocytes was observed on a fresh, Wright-Giemsa-stained preparation from cytocentrifuged urine. The cat was euthanized and necropsy was completed. Bilateral renomegaly was identified and characterized by multifocal, pale-yellow, coalescing, poorly defined, homogenous nodules. Microscopically, these nodules were composed of dense sheets of CD3-positive round cells, consistent with T-cell renal lymphoma. Key clinical message: Lymphoma is a common neoplasm in cats that can affect many organ systems, including the upper urinary tract. This case represents an uncommon method of identifying neoplastic lymphocytes via evaluation of cytocentrifuged urine, and emphasizes the benefits of examining Romanowsky-stained urine sediment in animals.

Diagnostic du lymphome rénal chez un chat par évaluation d'urine cytocentrifugée avec coloration Wright-Giemsa. Le lymphome représente jusqu'à 30 % des néoplasmes diagnostiqués chez le chat. Le diagnostic d'un lymphome du système urinaire par examen des sédiments urinaires a été décrit chez un chien, mais apparemment pas à ce jour chez le chat. Des échantillons simultanés de sérum, de sang total dans un tube avec EDTA et d'urine ont été soumis provenant d'une chatte domestique à poils courts stérilisée de 15 ans présentant une perte de poids, une polyurie et une polydipsie. Les anomalies hématologiques et biochimiques comprenaient une légère anémie normocytaire, normochrome et non régénérative; une formule leucocytaire inflammatoire; et une azotémie. L'analyse d'urine a révélé une concentration urinaire insuffisante et une protéinurie marquée. L'examen microscopique des sédiments urinaires a révélé un nombre modéré de leucocytes et d'érythrocytes. Une population uniforme de lymphocytes de taille intermédiaire à grande a été observée sur une préparation fraîche colorée au Wright-Giemsa à partir d'urine cytocentrifugée. Le chat a été euthanasié et une autopsie a été réalisée. Une rénomégalie bilatérale a été identifiée et caractérisée par des nodules multifocaux, jaune pâle, coalescents, mal définis et homogènes. Au microscope, ces nodules étaient composés de feuilles denses de cellules rondes CD3-positives, compatibles avec un lymphome rénal à cellules T.Message clinique clé :Le lymphome est une tumeur courante chez le chat qui peut affecter de nombreux systèmes organiques, y compris les voies urinaires supérieures. Ce cas représente une méthode rare d'identification des lymphocytes néoplasiques via l'évaluation de l'urine cytocentrifugée et met l'emphase sur les avantages de l'examen des sédiments urinaires avec coloration de Romanowsky chez les animaux.(Traduit par Dr Serge Messier).

Outcome of serial cardiac evaluations during doxorubicin-based chemotherapy in small- to medium-sized dogs with multicentric lymphoma.

Doxorubicin is an anthracycline antitumor antibiotic with dose-dependent and cumulative cardiotoxicity. However, the necessity for serial cardiac evaluation is unknown in dogs without risk factors for dilated cardiomyopathy (DCM). This study aimed to investigate serial changes in echocardiographic and electrocardiographic measures in small- and medium-sized dogs after four doxorubicin doses. We included 17 dogs, weighting < 20 kg, with multicentric lymphoma. All dogs received doxorubicin over 30 min every 4 weeks as part of a multi-drug chemotherapy protocol. The average doxorubicin dose was 3.8 times per dog. Clinical cardiotoxicity was not observed during the monitoring period. The incidence of developing arrhythmia was not significantly associated with the number of doxorubicin doses received (P = 0.600). The development of valvular regurgitations and mitral regurgitation in these dogs was not significantly associated with the number of doxorubicin doses (P = 0.363 and P = 0.779, respectively). The other echocardiographic results were not significantly different between each evaluation. In conclusion, our results showed no significant cardiotoxicity under echocardiogram and electrocardiogram in small- and medium-sized dogs without risk factors for DCM after four doses of doxorubicin in a 30-minute infusion method.

Elevated levels of IL-12/IL-23p40 in Nova Scotia Duck Tolling Retrievers with autoimmune disease and lymphoma.

The Nova Scotia Duck Tolling Retriever (NSDTR) is predisposed to immune mediated rheumatic disease (IMRD), steroid-responsive meningitis-arteritis (SRMA) and certain forms of cancer. Cytokines are the main regulators of the immune system. Interleukin 2 is a cytokine involved in activation of T regulatory cells, playing a role in central tolerance and tumor immunity. Interleukin 12 and interleukin 23 share the same subunit, p40, and are both pro-inflammatory cytokines. The aim of this study was to compare levels of IL-2 in healthy NSDTRs to those with cancer or autoimmune disease and to compare levels of IL-12/IL-23p40 in healthy NSDTRs and beagles versus NSDTRs with cancer or autoimmune disease. 62 dogs were included in the analysis of IL-12/IL-23p40; healthy NSDTRs (n = 16), healthy beagles (n = 16), NSDTRs autoimmune (n = 18) and NDSTRs lymphoma/mastocytoma (n = 12) and 68 dogs for IL-2; healthy (n = 20), autoimmune (n = 36) and lymphoma/mastocytoma/adenocarcinoma (n = 12). NSDTRs with autoimmune disease had higher levels of IL-12/IL-23p40 compared to healthy dogs (p = 0.008). NSDTRs with lymphoma also had higher levels of IL-12/IL-23p40 compared to healthy NSDTRs (p = 0.002). There was no difference in levels of IL-2 between healthy and diseased NSDTR. Statistical analysis was performed using Bonferroni corrections for multiple testing. These findings can contribute to the knowledge of autoimmune disease and cancer in dogs.

Alternating rabacfosadine and doxorubicin for treatment of naïve canine lymphoma.

The current standard of care treatment for canine lymphoma is a multi-agent, CHOP-based chemotherapy protocol. Single agent doxorubicin (DOX) is less burdensome; however, multi-agent chemotherapy protocols are often superior. The recently approved drug rabacfosadine (RAB, Tanovea) provides an attractive option for combination therapy with DOX, as both drugs demonstrate efficacy against lymphoma and possess different mechanisms of action. A previous study evaluating alternating RAB/DOX reported an overall response rate (ORR) of 84%, with a median progression-free survival time (PFS) of 194 days. The aim of this prospective trial was to evaluate the same protocol in an additional population of dogs. Fifty-nine dogs with treatment naïve lymphoma were enrolled. RAB (1.0 mg/kg IV) was alternated with DOX (30 mg/m2 IV) every 21 days for up to six total treatments (3 cycles). Response assessment and adverse event (AE) evaluation were performed every 21 days using VCOG criteria. The ORR was 93% (79% CR, 14% PR). The median time to maximal response was 21.5 days; median PFS was 199 days. T cell immunophenotype and lack of treatment response were predictive of inferior outcomes. AEs were mostly gastrointestinal. Six dogs developed presumed or confirmed pulmonary fibrosis; four were grade 5. One dog experienced grade 3 extravasation injury with RAB that resolved with supportive treatment. These data mirror those of the previously reported RAB/DOX study, and support the finding that alternating RAB/DOX is a reasonable treatment option for canine lymphoma.

Evaluation of clinical response and prognostic factors in canine multicentric lymphoma treated with first rescue therapy.

Despite an initial strong response in most dogs with multicentric lymphoma treated with chemotherapy, relapse remains common. There is no clearly superior first rescue protocol described either for resistant or relapsed canine multicentric lymphoma. The objectives of this study were to assess clinical response and outcomes for canine multicentric lymphoma treated with first rescue protocols. The secondary objective was to assess prognostic variables for dogs undergoing these protocols. This was a bi-institutional retrospective cohort study. Two hundred and sixty-five dogs were treated with first rescue chemotherapy, including anthracycline-based combination chemotherapy (CHOP-like, n = 50), nitrosourea alkylating agent-rich chemotherapy (n = 45), anthracycline-based or related compound chemotherapy (n = 34), or nitrosourea single-agent chemotherapy (n = 136). The overall median progression free survival time of first rescue protocol was 56.0 days (0-455 days). Important prognostic factors identified for first rescue protocol included the attainment of a complete response to the first rescue chemotherapy (p < .001), the use of a CHOP-like first rescue protocol (p = .009), duration of first remission (HR 0.997, p = .028), and if prednisolone was included in the first rescue protocol (HR 0.41, p = .003). Adverse events (AE) were common, with 81.1% of dogs experiencing at least one AE during first rescue chemotherapy. This study highlights the need for improved first rescue therapies to provide durable remission in canine resistant or relapsed lymphoma.

Lymphomas in seabirds: case reports in a black skimmer (Rynchops niger) and a brown booby (Sula leucogaster).

A black skimmer (Rynchops niger) and a brown booby (Sula leucogaster) were rescued and gross, histopathological, immunohistochemical and polymerase chain reaction evaluations were conducted to investigate the cause of death. There were neoplastic infiltrations of CD3+ PAX5- lymphocytes in the black skimmer and CD3- PAX5+ lymphocytes in the brown booby. Molecular assays for viral agents were negative in both cases. This is the first report of disseminated lymphoma as the cause of stranding and death in these species in Brazil.

Vincristine-induced adverse events related to body weight in dogs treated for lymphoma.

BACKGROUND: Traditional dosing of chemotherapy drugs based on body surface area may overdose small dogs, leading to an increased frequency of adverse events (AEs). HYPOTHESIS/OBJECTIVES: Evaluate the frequency of hematologic and gastrointestinal AEs in dogs with newly diagnosed lymphoma treated with vincristine weighing ≤15 kg in comparison to dogs weighing >15 kg. We hypothesized that dogs weighing ≤15 kg would experience a higher frequency of AEs. ANIMALS: One hundred and thirty-eight dogs with newly diagnosed lymphoma were treated with vincristine. METHODS: A multicenter retrospective study reviewing hematologic data and medical record information. Complete blood counts were performed no more than 24 hours before vincristine administration and then between 4 and 8 days post-administration. Data were evaluated using logistic regression or ordinal logistic regression. RESULTS: Thirty-eight dogs weighing ≤15 kg and 100 dogs weighing >15 kg were included. The median vincristine dose for both groups was 0.6 mg/m2. Seventeen (12.3%) instances of neutropenia occurred with no significant difference in overall frequency or grade between groups. Thirty initially asymptomatic substage A dogs (29.4%) experienced gastrointestinal AEs. Because of the widespread use of gastrointestinal supportive care medications, statistical comparison between groups could not be performed. Seven instances of hospitalization occurred (5.0%) and the risk of hospitalization did not differ significantly between groups (P = .37). CONCLUSIONS AND CLINICAL IMPORTANCE: Vincristine dosed at ≤0.6 mg/m2 does not increase the risk of hematologic AEs in dogs weighing ≤15 kg.

Stage Migration in Canine Multicentric Lymphoma: Impact of Diagnostic Techniques on Assessing Disease Extent.

BACKGROUND/AIM: Stage migration, a phenomenon triggered by technological advancements allowing more sensitive tumor spread detection, results in alterations in the distribution of cancer stages within a population. Canine multicentric lymphoma is staged I to V based on the affected anatomic site(s) and substage a or b depending on the presence of tumor-related clinical signs. The primary objective of this study was to assess the influence of various diagnostic techniques on staging accuracy and determine whether multiple staging methods lead to significant stage migration, impacting the reliability of disease stage assignments. MATERIALS AND METHODS: Dogs cytologically diagnosed with multicentric lymphoma were staged using four different staging methods (A-D): A (physical examination, hemogram, blood smear), B (A plus thoracic X-ray, abdominal ultrasound), C (B plus liver and spleen cytology) and D (C plus bone marrow cytology). RESULTS: Twenty-three dogs were enrolled: 16 females (70%) and seven males (30%). Regarding immunophenotype, 21 dogs (91.3%) were B-cell and two dogs (8.7%) were T-cell. Stage migration was observed between all staging methods. Between A and B, 12 animals migrated from stage III to stage IV. Between B and C, four animals migrated, three to a higher stage (stage III to IV) and one to a lower stage (stage IV to III). Between C and D, one animal migrated from stage IV to V. The differences between staging methods A and B were statistically significant (p≤0.001). CONCLUSION: Stage migration in canine multicentric lymphoma depends on the diagnostic methods used and reinforces the need to use standardized staging methods to avoid it.

Environmental radon, fracking wells, and lymphoma in dogs.

BACKGROUND: Multicentric lymphoma (ML) in dogs resembles non-Hodgkin lymphoma (NHL) in humans. Human NHL is associated with multiple environmental exposures, including to radon and volatile organic compounds (VOCs). HYPOTHESIS/OBJECTIVES: The objective of this study was to determine whether ML in dogs was associated with environmental radon or proximity to horizontal oil and drilling (fracking), a source of VOC pollution. METHODS: We identified dogs from the Golden Retriever Lifetime Study that developed ML (n = 52) along with matched controls (n = 104). Dog home addresses were categorized by Environmental Protection Agency radon zone and average residential radon by county, as well as by distance from fracking and associated wastewater wells. RESULTS: We found no significant differences in county level radon measurements. Individual household radon measurements were not available. There was no difference in residential proximity to active fracking wells between dogs with ML and unaffected dogs. While dogs with ML lived closer to wastewater wells (123 vs 206 km; P = .01), there was no difference in the percentage of cases vs controls that lived in close proximity (20 km) to a fracking well (11.5% for cases, 6.7% for controls; OR 1.81, 95% CI 0.55 to 5.22; P = .36), or a wastewater well (6.7% for cases, 4.4% for controls; P > .99). CONCLUSIONS AND CLINICAL IMPORTANCE: These data suggest that more proximate sources of chemical exposures need to be assessed in dogs with ML, including measurements of individual household radon and household VOC concentrations.

Comparison of chemotherapy outcomes between normal and high serum cortisol concentration in dogs with lymphoma.

BACKGROUND: Increased serum cortisol (COR) concentrations may induce glucocorticoid resistance by down-regulation of glucocorticoid receptor (GCR), resulting in decreased chemotherapy efficacy in dogs with lymphoma. HYPOTHESIS: Investigate the relationship between serum COR concentrations and chemotherapy outcomes in dogs with lymphoma. ANIMALS: Thirty client-owned dogs with lymphoma, with serum COR concentration measured using serum samples collected at diagnosis. METHODS: Retrospective study. Dogs were divided into 2 groups based on serum COR concentrations: a normal group (n = 16) with COR concentrations <6 µg/dL and a high group (14) with COR concentrations ≥6 µg/dL. We compared signalment, clinical signs, stage, type of lymphoma, adrenal gland size, alkaline phosphatase (ALP) activity, response to chemotherapy, progression-free survival (PFS), overall survival (OS), and rate of P-glycoprotein (P-gp)- and GCR-positive cells between the 2 groups. RESULTS: No significant differences were found in the demographic characteristics between the 2 groups. However, the high COR group exhibited a significantly lower response to chemotherapy, PFS, and OS compared with the normal COR group. Serum ALP activity was significantly higher in the high COR group than in the normal COR group. Adrenal gland size was also significantly larger in the high COR group. Although no significant differences were found in the rate of P-gp-positive cells between the 2 groups, the rate of GCR-positive cells was significantly lower in the high COR group. CONCLUSIONS AND CLINICAL IMPORTANCE: Our data suggests that measurement of serum COR concentrations may serve as a potential prognostic factor and evaluation index.

Assessment of left and right ventricular systolic function in dogs with multicentric lymphoma.

OBJECTIVE: Myocardial dysfunction in cardio-oncology is generally thought to be related to the cardiotoxicity of chemotherapy treatment. However, it is known that some tumors have direct effects on myocardial function. These effects have already been studied in man, but there are no publications of these of the effects in dogs. Novel advanced echocardiographic techniques may allow early detection of myocardial dysfunction when compared to conventional echocardiographic techniques. This study aims to assess myocardial systolic function in dogs with multicentric lymphoma prior to initiation of chemotherapy. ANIMALS: Fifteen dogs with multicentric lymphoma and nineteen healthy dogs. METHODS: Case-control study. Dogs with multicentric lymphoma and healthy control dogs underwent physical examination, electrocardiography, systolic blood pressure measurement, standard and speckle tracking echocardiography to assess biventricular systolic function. RESULTS: There were no differences between groups in terms of ejection fraction, fractional shortening, left ventricular systolic and diastolic diameter, tricuspid annular plane systolic excursion, mitral annular plane systolic excursion and fractional area change of the right ventricle (RV). However, there was a reduction in the values of global circumferential strain (p = 0.0003), RV strain (p = 0.01) and RV tissue motion annular displacement (p < 0.05) in the dogs with lymphoma when compared to the control group. CONCLUSIONS: Speckle tracking techniques appear to demonstrate early systolic dysfunction, primarily affecting the RV, in dogs with lymphoma prior to chemotherapy treatment.

Jaundice caused by primary common bile duct lymphoma of a cat.

A 10-year-old American Shorthair cat presented with anorexia and jaundice, and echogenic evaluation revealed diffuse thickening of the common bile duct (CBD) wall. An exploratory laparotomy was conducted, the lesion was evaluated as difficult to remove, and the cat was euthanized and autopsied. Histologically, round neoplastic cells proliferated in the mucosa of the CBD and infiltrated the hepatic lobe, pancreas, and duodenum. Immunohistochemistry revealed that the neoplastic cells were positive for cytoplasmic-CD3 and granzyme B, and TCR-gamma clonal rearrangement was detected. Based on these findings, the neoplasia was diagnosed as a primary CBD lymphoma originating from cytotoxic T or natural killer cells. To the best of our knowledge, this is the first reported case of feline primary CBD lymphoma. Although rare, lymphoma of the CBD should be considered in cats with jaundice and thickening of the CBD.

Multicentric lymphoma in a donkey with intestinal and bone marrow involvement.

BACKGROUND: Lymphoma is a common neoplasm in horses but is reported much less commonly in donkeys. In this case report, we describe the macroscopic, microscopic and immunohistochemical features of a multicentric lymphoma with intestinal and bone marrow involvement. CASE PRESENTATION: A geriatric female donkey with history of chronic lameness was found dead. Post-mortem examination revealed advanced emaciation, periodontal disease, left front foot laminitis and multiple, soft, white to yellow tan intestinal transmural masses, up to 12 cm in diameter. Cytology suggested a round cell intestinal neoplasm. The femur of the left hint limb was double the size of the normal contralateral, with suspected neoplastic infiltration and replacement of bone marrow and bone. Histologically we diagnosed a lymphoma in the intestine and left femur. Immunohistochemically, the neoplastic cells showed CD3 immunolabelling, supporting a diagnosis of a multicentric T-cell lymphoma. CONCLUSIONS: To the authors' knowledge, this is the first time multicentric lymphoma is diagnosed in donkeys. Further studies of the genetic background, clinical, laboratory, histopathologic, and immunohistochemical, as well as the pathogenesis of lymphoma, is needed to better understand the uniquely low frequency of this neoplasm in donkeys.