犬皮肤淋巴瘤，表现为大颗粒淋巴细胞非 B、非 T 自然杀伤免疫表型，并累及心脏、胃和肝脏

Cases of natural killer (NK)-cell large granular lymphocyte lymphoma are extremely rare, accounting for approximately 0. 8% to 2. 56% of lymphomas in dogs. A 5-year-old male Rottweiler presented with multiple cutaneous nodules and progressive weight loss, with a clinical course of less than 2 months. Following inconclusive cytology, an incisional biopsy was performed for histopathological and immunohistochemical analyses. Histopathological examination revealed a neoplastic proliferation of round cells infiltrating the deep dermis and subcutaneous tissue. The microscopic features, combined with the immunostaining profile-negative for CD3 and CD79a and positive for CD18 and granzyme-indicated a diagnosis of large granular lymphocyte lymphoma with a non-B/non-T immunophenotype of NK-cell origin. The patient underwent chemotherapy with lomustine and completed three treatment sessions before being euthanized, with a survival time of 93 days. Necropsy revealed involvement of the lymph nodes, heart, stomach, liver, and skin. Histopathological and immunohistochemical findings confirmed the antemortem diagnosis at all sites. To the best of our knowledge, this is the first report of cutaneous, cardiac, gastric, and hepatic involvement associated with non-B, non-T large granular lymphocyte lymphoma in dogs.

Casos de linfoma de grandes linf citos granulares de c lulas natural killer (NK) s o extremamente raros, representando aproximadamente 0,8% a 2,56% dos linfomas em c es. Um c o da ra a Rottweiler, macho e com 5 anos de idade, apresentou m ltiplos n dulos cut neos e perda de peso progressiva, com um curso cl nico inferior a dois meses. Ap s citologia inconclusiva, realizou-se bi psia incisional para an lises histopatol gica e imuno-histoqu mica. O exame histopatol gico revelou uma prolifera o neopl sica de c lulas arredondadas infiltrando a derme profunda e o tecido subcut neo.

As caracter sticas microsc picas, combinadas com o perfil de imunomarca o negativo para CD3 e CD79a e positivo para CD18 e granzima , indicaram o diagn stico de linfoma de grandes linf citos granulares com imunofen tipo n o-B/n o-T de origem em c lulas NK. O paciente foi submetido quimioterapia com lomustina e completou tr s sess es de tratamento antes de ser submetido eutan sia, apresentando um tempo de sobrevida de 93 dias.

A necropsia revelou comprometimento de linfonodos, cora o, est mago, f gado e pele. Os achados histopatol gicos e imuno-histoqu micos confirmaram o diagn stico antemortem em todos os locais. At onde sabemos, este o primeiro relato de acometimento cut neo, card aco, g strico e hep tico associado ao linfoma de linf citos granulares grandes n o B, n o T em c es.