What is this lesion on the upper eyelid of a three year old crossbred dog likely to be?
While this could be inflammatory, the liklihood is that it is neoplastic. Complete excision yielded this histopathology. Note how the tumour cells hug the epithelium – their cell phenotype shows this to be a histiocytoma. Go back to the clinical picture and notice how the hairs stand erect within the body of the mass. This is another feature of this type of tumour because of the infiltration around the hair follicles.