A mesenchymal hamartoma in the dorsomedial eyelid of a Staffordshire bull terrier and the incidence and histological features of twenty-two canine mesenchymal periocular hamartoma cases are reported. The archives of the “Comparative Ocular Pathology Laboratory” of Wisconsin (USA) were searched for canine mesenchymal periocular hamartoma. Signalment, clinical appearance, location and histological findings are summarized for twenty-two dogs, containing fourteen different breeds, between four and fourteen years old. Fifteen hamartomas were located at the lateral canthus. Histologically, they consisted of fully differentiated fibrous tissue interspersed with adipose tissue, with bundles of skeletal/smooth muscle in ten cases, and peripheral nerve tissue in two cases. No mitotic figures were noted. Mesenchymal hamartomas may present as a subcutaneous, subconjunctival or orbital mass. Although they have a predisposition to occur at the lateral canthus, they may be located elsewhere on the eyelids or in the orbit.

An 8-year-old Scottish terrier was presented with a red and painful right eye. Slitlamp biomicroscopy and ocular ultrasound demonstrated the presence of a large mass in the anterior chamber. Enucleation was performed one week after initial presentation. Histological examination of the eye revealed a relatively well-delineated mass distorting the dorsal iris and occupying most of the anterior chamber. The tumor was composed of fully differentiated adipose tissue and normal hematopoietic cells of the three major blood-forming elements. These findings were most consistent with the diagnosis of an anterior chamber myelolipoma distorting the iris. To the author's knowledge, this is the first report of an intraocular myelolipoma in any species.

A 14-year-old, female, spayed Domestic Shorthair cat was presented for evaluation of a dark red mass occupying about 75% of the cornea of the left eye. Furthermore, the eye presented upper eyelid trichiasis, lower eyelid entropion and a marked symblepharon. The fellow eye presented upper eyelid trichiasis, lower eyelid entropion, extensive symblepharon and chronic stromal ulcerative keratitis. Based on the results of a corneal biopsy of the left eye, a corneal squamous cell carcinoma was diagnosed and an enucleation was performed subsequently. Histopathology of the globe revealed the presence of variably sized, vascular-like, blood-filled channels in the superficial corneal stroma, lined by spindle cells. In the central cornea, a markedly hyperplastic epithelium was noticed with infiltration of atypical corneal epithelial cells into the superficial stroma. A primary corneal hemangiosarcoma associated with a primary corneal squamous cell carcinoma was diagnosed. In this case report, the rare presence of multiple primary neoplasms within the same anatomical structure is described.