What are your differentials for mineralized pulmonary nodules?

Known Case Conference

This week at KCC we moved back to the digital realm so I have some images for you to look at. Though I do need to save some to surprise our residents with next year!

Case 1

This case is a 10 year old female neutered Jack Russell Terrier with a 6 month history of coughing. These radiographs are really impressive! On thoracic radiographs, there are multiple, large, mineralized pulmonary masses in all lung lobes. There are also some smaller nodules in the right caudal lung lobe. Differential diagnoses included metastatic osteosarcoma, primary lung tumor with multiple metastases, granulomas (fungal, parasitic), and other metastatic disease. Diagnosis: Primary pulmonary carcinoma.

Case 2

Next was a 9 year old female neutered Bernese Mountain Dog with coughing and decreased appetite. 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 diagnoses included histiocytic sarcoma and granulomatous disease. This was a very typical appearance of histiocytic sarcoma, with ill-defined and well-defined pulmonary masses, lobar infiltration, and lymphadenopathy. Faculty commented that Roentgen findings of masses, lymphadenopathy and alveolar pattern should lead you to differentials of PIE and histiocytic sarcoma.

Case 3

This case of a 2 year old Labrador Retriever was an old one, still on film radiographs. The dog presented with ascites. The thoracic radiographs were relatively normal, with the exception of an enlarged caudal vena cava. The abdomen included was distended and had poor detail, consistent with the history of ascites. Differentials included common congenital heart diseases such as septal defects and left to right shunts causing right heart failure. But if you think about it, all of those diseases result in an enlarged heart which this was not. Our second year resident nailed it by diagnosing cor triatriatum dexter. In this congenital condition, there are septae within the right atrium that block inflow of blood from the caudal vena cava and cause obstructive disease. Rare, but classic!