Fantastic Case #2
Multicentric Squamous Cell Carcinoma in situ
and Invasive Squamous Carcinoma in a Basenji
If you reviewed Fantastic Case #1, you may see some similarities in the gross appearance of the lesions seen here. Both dogs have raised pigmented plaques, although some lesions in this Basenji were less superficial with evidence of deeper infiltration. In this case the histologic appearance of some lesions was similar to the pigmented plaques described in case 1, but others had the appearance seen in the photomicrograph above. The epidermis is thickened and has pigment, but also has epidermal cells with increased basophilia due to increased nuclear to cytoplasmic ratio and there is loss of normal organization of cells in addition to the very dark, small cells seen that represent single cell necrosis. Epidermal cells had moderate pleomorphism with mitoses above the basal layer. There were other lesions in which neoplastic cells invaded the dermis and subdermal tissues. Eventually this dog also developed metastatic squamous cell carcinoma in the lymph node and lung.
Multicentric squamous cell carcinoma is more common in cats and very rarely seen in dogs, but, in both species papillomavirus has been isolated from lesions. In dogs, a unique papillomavirus is being sequenced and papillomavirus was identified with PCR in this case. Dogs often have long progression and lesions may vary in appearance from benign epidermal plaques to carcinoma in situ or invasive squamous carcinoma. Metastasis is extremely rare, making this case unique and we will be sequencing the virus identified in the metastatic lesions.
References: Mary Beth Callan et al. Multiple papillomavirus-associated epidermal hamartomas and squamous cell carcinomas in situ in a dog following chronic treatment with prednisone and cyclosporine. Vet Dermatol.
October 2005;16(5):338-45.
N Zaugg et al. Detection of novel papillomaviruses in canine mucosal, cutaneous and in situ squamous cell carcinomas. Vet Dermatol. October 2005;16(5):290-8.
Multicentric Squamous Cell Carcinoma in situ
and Invasive Squamous Carcinoma in a Basenji
If you reviewed Fantastic Case #1, you may see some similarities in the gross appearance of the lesions seen here. Both dogs have raised pigmented plaques, although some lesions in this Basenji were less superficial with evidence of deeper infiltration. In this case the histologic appearance of some lesions was similar to the pigmented plaques described in case 1, but others had the appearance seen in the photomicrograph above. The epidermis is thickened and has pigment, but also has epidermal cells with increased basophilia due to increased nuclear to cytoplasmic ratio and there is loss of normal organization of cells in addition to the very dark, small cells seen that represent single cell necrosis. Epidermal cells had moderate pleomorphism with mitoses above the basal layer. There were other lesions in which neoplastic cells invaded the dermis and subdermal tissues. Eventually this dog also developed metastatic squamous cell carcinoma in the lymph node and lung.
Multicentric squamous cell carcinoma is more common in cats and very rarely seen in dogs, but, in both species papillomavirus has been isolated from lesions. In dogs, a unique papillomavirus is being sequenced and papillomavirus was identified with PCR in this case. Dogs often have long progression and lesions may vary in appearance from benign epidermal plaques to carcinoma in situ or invasive squamous carcinoma. Metastasis is extremely rare, making this case unique and we will be sequencing the virus identified in the metastatic lesions.
References: Mary Beth Callan et al. Multiple papillomavirus-associated epidermal hamartomas and squamous cell carcinomas in situ in a dog following chronic treatment with prednisone and cyclosporine. Vet Dermatol.
October 2005;16(5):338-45.
N Zaugg et al. Detection of novel papillomaviruses in canine mucosal, cutaneous and in situ squamous cell carcinomas. Vet Dermatol. October 2005;16(5):290-8.
