Question of the day

A five-year-old female spayed Australian shepherd is presented for poor appetite and lethargy.

Bloodwork reveals hypercalcemia. Urinalysis is normal. Abdominal ultrasonography is unremarkable. Thoracic radiographs are shown below.

Which of the following choices is the most likely diagnosis?

Idiopathic hypercalcemia

Hypertrophic osteopathy

Metastatic lung disease

Hepatic parathyroid hormone-related protein releasing tumor

Mediastinal lymphoma