A Case of Canine Malignant Histiocytosis

Abstract

An 8-year-old female Rottweiler dog with anorexia, depression and the left hindimb lameness, showed groundglass shadows in the cranial peritoneal cavity and caudal disposition of the intestinal gas content by abdominal radiography. Remarkable splenomegaly with various-sized round hypoecho areas were observed by abdominal ultrasonography. Laparotomy revealed accumulation of bloody fluid in the peritoneal cavity and remarkable splenomegaly with multiple grayish-white nodules variable in size and partly hemorrhagic, and splenectomy was performed. Histopathology of the spleen revealed malignant histiocytosis characterized by disappearance of the normal structure, invasive proliferation of atypical histiocytes and multinucleated giant cells, frequent mitosis, erythrophagocytosis. At 18 days postoperation, hepatomegaly and a nodular lesion in the right cranial lung lobe were detected by radiography and at 4 weeks postoperation, several nodular lesions appeared in the cervical and abdominal skin. Taking a turn for the worse later, the patient died at 36 days postoperation.