This week’s case is a 9-year-old Bernese Mountain Dog that is coughing and has a decreased appetite.
Findings
There are multiple soft tissue masses in the pulmonary parenchyma, including the caudal subsegment of the left cranial lung lobe, right cranial lung lobe, and right middle lung lobe. The cranial mediastinum is widened and increased in opacity, indicating lymphadenopathy. The increased soft tissue opacity and widening of the main stem bronchi indicate hilar lymphadenopathy.Differential Diagnosis
- round cell neoplasia (histiocytic sarcoma, less likely lymphoma)
- granulomatous disease
Diagnosis
Histiocytic sarcomaDiscussion
Multiple pulmonary masses and lymphadenopathy are characteristic of histiocytic sarcoma. The Bernese Mountain Dog is predisposed to this disease. Lymphoma can manifest a similar lymphadenopathy, however the pulmonary infiltrate is usually a diffuse, interstitial pattern. Granulomatous disease is also less likely to cause pulmonary masses. Since this disease is often multicentric, abdominal ultrasound is warranted.References
- Shaiken LC, Evans SM, Goldschmidt MH. Radiographic findings in canine malignant histiocytosis. Veterinary Radiology 1991;32:237-242.
- Ramirez S, Douglass JP, Robertson ID. Ultrasonographic features of canine abdominal malignant histiocytosis. Veterinary Radiology & Ultrasound 2002;43:167-170.
- Cruz-Arambulo R, Wrigley R, Powers B. Sonographic features of histiocytic neoplasms in the canine abdomen. Veterinary Radiology & Ultrasound 2004;45:554-558.