Image Challenge in Veterinary Pathology

Image 1

Cow. Diagnosis?

Image 2.

Ferret, haired skin. Immunohistochemical marker to confirm the diagnosis?

Image 3.

Dog, proximal humerus. Discriminating immunohistochemical marker?

Image 4.

Large felid. Most common in which species?

Answers are provided in Veterinary Pathology, 59(5): 883–884