Multiple cutaneous mast cell tumours in a Boa imperator
Mast cell tumours (MCTs) are common in dogs and cats, but are only rarely reported in reptiles. This case documents the clinical and pathomorphological results from a Boa imperator with multiple cutaneous nodules, diagnosed as MCT based on histopathology, immunohistochemistry and electron microscopy approaches. Grossly, there were multifocal, poorly demarcated, mostly ulcerated nodules ~3 cm in diameter on the skin. Histologically, the dermis and the subcutaneous tissue were infiltrated by round cell populations with eosinophilic granules. Toluidine blue and Giemsa stain revealed metachromatic granules. Using immunohistochemistry, some cells exhibited cytoplasmic immunostaining positive for tryptase. Ultrastructurally, variable quantities of intracytoplasmic, spherical and electron-dense granules were also detected. The MCT literature on snakes is scarce, especially for the family Boidae, but MCTs should be considered a differential diagnosis for nodular skin lesions in reptiles.