Case Study

Lymphoma diagnosed by trucut biopsy of mediastinal lymph node in a 7-year-old MN Boxer dog

A 7-year-old MN Boxer with history of hypothyroidism (on Soloxine) was presented for PU/PD and decreased appetite. Physical examination of the dog was non-remarkable. Abnormalities on blood chemistry were elevated ALP and ALT activity, marked hypercalcemia, and hyperglobulinemia. An ACTH stimulation test was within normal range.

DX

Lymphoma, enlarged mediastinal lymph nodes

Sonographic Differential Diagnosis

Cranial mediastinal parenchymal mass: lymphoma or similar neoplasia likely, thymoma minimally possible.

Image Interpretation

A large, dramatically hypoechoic to anechoic cranial mediastinal mass is noted. This is likely of lymph node origin given that no trapped air is present nor is there peripheral scalloping of a normal lung/alveolar air interface. The linear focus in video 2 represents core biopsy trajectory into the mass.

Outcome

Biopsy revealed lymphoma.

Clinical Differential Diagnosis

Neoplasia (lymphoma/anal sac carcinoma/soft tissue sarcomas), granulomatous disease (idiopathic/fungal), hypervitaminous D, renal disease, hyperparathyroidism