Large granular lymphoma in six cats.

Abstract

Large granular lymphomas (LGLs) comprise a specific group of lymphomas regardless of classifi- cation scheme. An LGL consists of cells that show less or more mature morphology, but typically neoplastic cells possess cytoplasmic azurophilic granules clearly visible during cytological examin- ation. The aim of the present study was to present clinical and cytological data on large granular lymphomas in cats and to analyses the therapeutic responses in treated cases. During the period from 2012 to 2014 six cats were as having large granular lymphoma. In one cat a nasal form of LGL was recognized, a systemic form was recognized in another cat, and in four cases an alimentary form was recognized. Cellular samples for cytopathology were collected from the cat with nasal cavity mass, from the enlarged mandibular lymph node and thoracic cavity from second cat, and in four cats from the abdominal mass during ultrasound-assisted fine-needle biopsy. Therapy was introduced in 5 of the 6 cats. In two cases palliative therapy with glucocorticoids was conducted, in two cases chemotherapy with COP protocol, and therapy with masitinib in one case. The median of survival time for cats treated with anticancer therapy was 9 months, the median of survival time for cats treated with glucocorticoids was 1.5 months. In conclusion, large granular lymphomas, especially the alimentary form, are a relatively common type of lymphoma in cats. Simple diagnostic methods such as clinical examination, imaging techniques and routine cytology are sufficient in majority of cases. Despite aggressive behavior and poor general prognosis, conventional chemotherapy lead to a good response in some treated cats regardless of anatomic form and histologic grade of malignancy.