Splenic myxoid liposarcoma in a dog

A 7-year-old Maltese was presented to a veterinary clinic for a history of anorexia, soft feces, and anemia. During abdominal sonography and computed tomography imaging, splenic mass was suspected. Laparotomy revealed the bloody ascites, and the enlarged spleen containing a large spherical mass. Microscopically, the splenic parenchyma was replaced by neoplastic cells with cytoplasmic vacuolation and abundant myxoid matrix. Cellular vacuolation and myxoid matrix were positive to Oil-Red-O and Alcian-blue stains. The neoplastic cells were positive to vimentin on immunohistochemistry. The case was diagnosed as myxoid liposarcoma. Based on a poor prognosis, the dog was euthanized three weeks after splenectomy.

Carcinoid tumor of gallbladder in a dog

A 7-year-old female mixed-breed dog was presented to a veterinary clinic for pyometra. During abdominal ultrasonography, an abnormal finding was noted in the gallbladder. A cholecystectomy was performed. Grossly, the gallbladder wall was thickened with a polypoid nodular projection into the lumen. Microscopically, the polyp consisted of a solid sheet of round to polygonal-shaped cells that formed small packets with fibrovascular septa. The neoplastic cells contained abundant cytoplasmic eosinophilic granules. Immunohistochemically, the neoplastic cells were positive to chromogranin A and neuron-specific enolase, whereas they were negative to vimentin and cytokeratin. This case was diagnosed as a primary gallbladder carcinoid tumor.

Fulminant multicentric osteosarcoma with systemic metastasis in a dog

A 15-year-old castrated mixed breed dog presented due to a 5-month history of cough and difficulty in ambulation. Necropsy showed multiple periosteal and intramedullary infiltrative masses in the appendicular skeleton. In addition, single and multiple neoplastic nodules were observed in several organs, including the lungs, liver, kidney, and heart. Microscopically, several skeletal neoplastic masses and nodules in the parenchymal organs revealed similar changes. The neoplastic cells were spindle- to polygonal-shaped with prominent osteoid production and occasional cartilaginous and bone formation. Based on the gross findings and histopathology results, the case was diagnosed as multicentric osteosarcoma with systemic metastases.

Amyloidosis in a Whooper swan (Cygnus cygnus)

Two Whooper swan (Cygnus cygnus) died after suffering from pododermatitis, lethargy, and ataxia; necropsy was performed. Grossly, the liver was swollen and firm. The kidney and spleen were also enlarged and a pale tan color. On histopathologic examination with Congo red staining, amyloidosis was noted in liver, spleen, and kidney. In addition, marked osseous metaplasia was present in the liver. Based on these results, systemic amyloidosis involving liver, spleen, and kidney with osseous metaplasia in the liver was diagnosed. Study results indicate that an inflammatory reaction associated with pododermatitis had a role in the amyloidosis in this particular case.

Ferret coronavirus infection in a domestic ferret (Mustela putorius furo)

A female domestic ferret (Mustela putorius furo) presented to a veterinary clinic with a clinical history of anorexia and poor body condition. Due to gradual deterioration of the body condition, explorative laparotomy was performed. Diffusely, the mesentery was severely thickened and adhered with prominent mesenteric lymph nodes. A portion of the mesentery and mesenteric lymph nodes were biopsied and fixed. Microscopic analysis revealed severe pyogranulomatous peritonitis and lymphadenitis, but staining revealed no bacterial organisms. However, immunohistochemistry for feline coronavirus exhibited strong immunoreactivity, primarily in the macrophages. Based on these results, the case was diagnosed as ferret coronavirus infection.

Pericardial mesothelioma in a dog with lymph node metastasis and chylothorax

Pericardial mesothelioma is a rare neoplasm in dogs. This report describes a case of pericardial mesothelioma in a 13-year-old Shih Tzu that presented with a clinical history of dyspnea. Hemorrhagic pericardial effusion and chylous pleural effusion with reactive mesothelial cells were identified by radiograph and cytology. Necropsy revealed multiple round nodules throughout the pericardium and regional lymph nodes in addition to chylothorax. Histopathology revealed invasive neoplasm on the pericardial surface with metastasis to the lymph nodes. The neoplastic cells were immunopositive to both cytokeratin and vimentin. Diagnosis of pericardial mesothelioma with regional lymph node metastasis was made.