Utility of flow cytometry in canine primary cutaneous and matched nodal mast cell tumor.

Mast cell tumors (MCT) are among the most frequent tumors in dogs, but studies regarding canine mast cell immunophenotype are lacking. The aim of this study was to assess the feasibility of flow cytometric analysis of MCTs, to describe canine MCTs immunophenotype(s), and to evaluate the ability of flow cytometry to detect mast cells in lymph node aspirates. Thirty-four primary canine MCTs and 12 draining lymph nodes were evaluated regarding the expression of CD117, IgE, CD11b, CD18, CD44, CD34, CD25 and CD45. Distinct populations attributable to mast cells and eosinophils were recognized based on light scatters and CD117 positivity. Common antigens (CD18, CD45, CD44) and CD117 were detected in all cases; positivity for IgE and CD11b was found in 28 (82%) and 23 (68%) cases respectively, while CD34 and CD25 were occasionally expressed. A single multicolor tube (IgE/CD117/CD11b/CD21/CD5) allowed the identification of mast cells in lymph nodes, showing a high correlation with cytology in quantifying mast cells infiltration. In conclusion, flow cytometric analysis can be applied to characterize canine MCTs and can be used to detect the presence of mast cells in lymph nodes. The immunophenotype abnormalities observed may be useful to confirm the neoplastic nature of such mast cells but the diagnostic usefulness of atypical antigen expression remains to be clarified.

Features and prognostic impact of distant metastases in 45 dogs with de novo stage IV cutaneous mast cell tumours: A prospective study.

BACKGROUND: Distant metastases in dogs with cutaneous mast cell tumors (cMCT) are rare and incurable. The aims of this prospective study were to clarify the clinico-pathological features of stage IV cMCTs and to identify possible prognostic factors for progression-free interval (PFI) and survival time (ST). MATERIAL AND METHODS: Dogs were eligible for recruitment if they had a previously untreated, histologically confirmed cMCT and if they underwent complete staging demonstrating stage IV disease. Dogs were uniformly followed-up, whereas treatment was not standardized and included no therapy, surgery, radiation therapy, chemotherapy, tyrosine-kinase inhibitors or a combination of these. RESULTS: 45 dogs with stage IV cMCT were enrolled. All dogs had distant metastatic disease, and 41 (91.1%) dogs had also metastasis in the regional lymph node. Histopathological grade and mutational status greatly varied among dogs. Median ST was 110 days. Notably, PFI and ST were independent of well-known prognostic factors, including anatomic site, histological grade, and mutational status. Conversely, tumor diameter >3 cm, more than 2 metastatic sites, bone marrow infiltration, and lack of tumor control at the primary site were confirmed to be negative prognostic factors by multivariate analysis. CONCLUSION: Currently, there is no satisfactory treatment for stage IV cMCT. Asymptomatic dogs with tumor diameter <3 cm and a low tumor burden, without bone marrow infiltration may be candidates for multimodal treatment. Stage IV dogs without lymph node metastasis may enjoy a surprisingly prolonged survival. The achievement of local tumor control seems to predict a better outcome in dogs with stage IV cMCT.

Feline large granular lymphocyte lymphoma: An Italian Society of Veterinary Oncology (SIONCOV) retrospective study.

Feline large granular lymphocyte (LGL) lymphoma is an uncommon subtype of lymphoma characterized by a grave prognosis and scarce response to chemotherapy. There are limited reports on clinico-pathological and prognostic factors. One-hundred and 9 cats with newly diagnosed LGL lymphoma that underwent initial staging (including hematology, serum biochemistry, thoracic radiographs and abdominal ultrasound), and followed-up were retrospectively evaluated. LGL lymphoma was localized within the gastrointestinal tract with or without extra-intestinal involvement in 91.7% of the cases, and at extra-gastrointestinal sites in 8.3%. Symptoms were frequent. Anemia (31.2%) and neutrophilia (26.6%) were commonly observed, and 14 (12.8%) cats had neoplastic circulating cells. Frequent biochemistry abnormalities included elevated ALT (39.4%) and hypoalbuminemia (28.4%). Twenty (54.1%) of 37 cats had elevated serum LDH. Treatment varied among cats, and included surgery (11%), chemotherapy (23%), corticosteroids (38.5%) and no treatment (27.5%). Median time to progression (MTTP) was 5 days, and median survival time (MST) 21 days. MST was significantly shorter in the case of substage b, circulating neoplastic cells, lack of chemotherapy administration, and lack of treatment response. A small subset of cats (7.3%) survived more than 6 months, suggesting that a more favorable clinical course can be found among LGL lymphoma patients.

Intraoral diode laser epiglottectomy for treatment of epiglottis chondrosarcoma in a dog.

Laryngeal tumours are rare in dogs. Surgery is the treatment of choice, but it is usually palliative in malignant conditions, due to advanced stage of the tumour at the time of diagnosis. In veterinary medicine, little information is available about the use of diode laser in laryngeal oncological surgery. In the case reported here, a dog with an epiglottic chondrosarcoma was successfully treated with diode laser epiglottectomy. The surgical technique and follow up are described.