Diagnosis and management of a peripheral T-cell lymphoproliferative disease in an American pine marten (Martes americana).

A 9-year-old neutered male American pine marten (Martes americana) was referred for further evaluation of suspected lymphoproliferative disease. On physical examination, the pine marten was determined to be in an underconditioned state with an enlarged right mandibular lymph node. Hematology revealed a marked leukocytosis characterized by a lymphocytosis. Flow cytometry performed on peripheral blood was suggestive of a CD4+ T-cell lymphoproliferative disease. Whole-body radiographs demonstrated a large cranial mediastinal mass and splenomegaly. These findings were confirmed using ultrasound, which also identified intra-abdominal lymphadenopathy and splenic nodules. Cytologic evaluation of aspirates from the mediastinal mass was interpreted as possible lymphoma. The pine marten was treated with chlorambucil and prednisolone and achieved a durable partial remission. Twelve months after initial diagnosis, progressive disease was noted and treatment with lomustine was initiated as a rescue protocol until euthanasia, which was carried out 15 mo after the initial diagnosis. Based on a literature search, this is the first case report describing the management of peripheral T-cell lymphoproliferative disease, presumably peripheral lymphoma, in a pine marten; this neoplasm should be considered as a differential diagnosis in pine martens that have abnormal complete blood cell count findings and enlarged lymph nodes. Key clinical message: This report describes the diagnosis and management of a peripheral T-cell lymphoproliferative disease, presumably peripheral lymphoma, in an American pine marten (Martes americana). This is the first report of this disease and its successful treatment in a pine marten.