Malignant transformation of a putative eyelid papilloma to squamous cell carcinoma in a dog

Abstract

A 6-year-old female spayed Chihuahua was presented for the evaluation of generalized pigmented cutaneous masses, one of which was present on the lower right eyelid. The dog was not on immunosuppressive medications and did not have historical or laboratory evidence of underlying endocrine disease, including hypothyroidism and hyperadrenocorticism. Histopathology, immunohistochemistry, and polymerase chain reaction of a cutaneous biopsy from the left antebrachium containing representative lesions confirmed viral papillomatosis. Additionally, histopathology of the antebrachial mass revealed regions of epithelial dysplasia suggestive of possible early transformation to malignancy. Over the course of 5 months, the mass on the right lower eyelid progressed to encompass and efface the majority of the eyelid margin. Additionally, the eyelid tumor had changed from an ovoid, brown pigmented mass to an irregular, flesh-colored mass. At the dog's last recheck examination, a corneal ulcer had developed beneath the irregular dorsal margin of the tumor. Histopathology of the eyelid mass was consistent with squamous cell carcinoma (SCC) and was positive for the presence of papillomavirus using polymerase chain reaction. This report describes the transformation of a putative viral eyelid papilloma into a malignant SCC in an adult dog.

Canine ocular neoplasia: a review

“…The adjacent corneal epithelium may be hyperplastic/dysplastic and is often pigmented. Corneal stromal inflammation and neovascularization are common findings when the stroma is available for histopathologic evaluation . In the few corneal squamous cell carcinomas assessed, immunoreactivity for cytokeratin (1/1), e‐cadherin (1/1), and GADD45 (1/1) with rare immunopositive cells for caspase 3 was detected.…”

“…Corneal stromal inflammation and neovascularization are common findings when the stroma is available for histopathologic evaluation. 9,11,[54][55][56][58][59][60][61][62] In the few corneal squamous cell carcinomas assessed, immunoreactivity for cytokeratin (1/ 1), e-cadherin (1/1), and GADD45 (1/1) with rare immunopositive cells for caspase 3 was detected. One of three masses was positive for p53.…”

p16 Immunostaining of Canine Squamous Cell Carcinomas Is Not Associated with Papillomaviral DNA

“…Naturally occurring PV infections have been demonstrated to cause benign epithelial proliferations, including exophytic or endophytic (inverted) papillomas and pigmented plaques [ 9 ]. Papillomas, most frequently occurring in young dogs [ 10 – 12 ], are associated with infection by Canis familiaris PV (CPV-1, canine oral PV), CPV-2, CPV-6 and CPV-7. Pigmented plaques, which have been reported to have breed predispositions in pugs and miniature schnauzers, are associated with CPV3-5, CPV-8-12 and CPV-16 [ 13 – 15 ].…”

Squamous Papillomas of the Conjunctiva in Dogs

“…Although some papilliferous growths are malignant or may undergo malignant transformation, most of these masses are benign. 8 Viral papillomas can be diagnosed by histopathology, polymerase chain reaction (PCR), immunohistochemistry, and in situ hybridization. By convention, viral papillomas are morphologically identified based on the presence of cytopathic effects within superficial epithelial cells, including hyperplasia of the stratum granulosum and formation of giant keratohyaline granules, keratinocytes with clear or amphophilic cytoplasm, and small, smudged, or vesiculate nuclei (koilocytes) or occasional basophilic intranuclear viral inclusions.…”