Pathogenic Idiopathic Extramedullary Hematopoiesis in a Yellow-Collared Macaw (Primolius auricollis).

1.5-year-old yellow-collared macaw (Primolius auricollis) was presented as a referral case for chronic breathing difficulties and coelomic distension. The bird was in poor body condition, and coelomic distension and green-colored urates were noted during the physical examination. Radiographic images revealed a large coelomic space-occupying soft-tissue lesion that was ultrasonographically confirmed to be hepatomegaly; the liver had a heterogeneous echogenic pattern. An ultrasound-guided fine needle aspirate of the liver was performed. The cytological results revealed immature hematopoietic cells with signs of dyserythropoiesis and were consistent with extramedullary hematopoiesis (EMH). The plasma biochemistry panel revealed a marked increase in aspartate aminotransferase and bile acids, consistent with severe hepatic disease. Following the results of the diagnostic tests, chemotherapy was initiated using hydroxyurea. Two weeks after the initial presentation and treatment, the bird died and a full postmortem examination was performed. Macroscopic examination confirmed severe hepatomegaly and severe splenomegaly. Histopathological examination of tissue samples confirmed severe EMH in the liver and spleen, splenic and renal hemosiderosis, and acute pulmonary congestion. The bone marrow was normal. The final diagnosis was pathogenic idiopathic EMH, and this case was unusual in both its presentation and severity. Extramedullary hematopoiesis is usually related to myeloid proliferative disorder, chronic blood loss, hemolytic disease, or chronic inflammatory disease. Mycobacteriosis and parasitic infection have been reported to be associated with EMH in birds; however, the inflammatory patterns seen in those cases were lacking in this case. Myeloproliferative neoplasia also appears an unlikely disease condition in this case considering that histopathology found normal architecture in the studied bone marrow; however, bone marrow abnormalities in locations other than the one sampled could not be excluded. A short review of homeostatic and pathogenic hematopoiesis in birds is provided to support the likely diagnosis of idiopathic EMH.

Multiple progressive piloleiomyomas in a ferret (Mustela putorius furo): a case report.

A 2.5-year-old ovariectomized female ferret developed multiple progressive linear and raised nodules on the skin. The first lesions occurred on the tail, which was then amputated. Over the following 3 years, additional lesions appeared in the vicinity of the scar and then further rostrally on the flanks and thorax. Histological and immunohistochemical investigation led to a diagnosis of multiple piloleiomyomas. The unique characteristics of this ferret disease are described and compared with those of multiple piloleiomyomas in humans and with those of other cutaneous smooth muscle cell tumours reported in the veterinary literature.

A KIT-positive gastrointestinal stromal tumor in a ferret (Mustela putorius furo).

A 1.5-year-old, neutered, male ferret (Mustela putorius furo) was presented with sudden lethargy, anorexia, and diarrhea. Clinical and radiographic examinations revealed an intra-abdominal mass. An explorative laparotomy was performed. A neoplasm, located in the ileum wall, was submitted for histopathologic examination. The tumor consisted of weakly eosinophilic spindle cells arranged in a compact pattern with haphazardly interlacing bundles. Neoplastic cells labeled positively for KIT (cluster of differentiation 117, stem cell factor receptor) and vimentin. Based on histologic and immunohistologic results, this tumor was diagnosed as a gastrointestinal stromal tumor. Results suggest that this ferret tumor shares strong similarities with the canine and human counterparts.