The reports of basal cell carcinoma (BCC) of the perianal and anal area are very infrequent in the dermatologic literature. It is important to distinguish this relatively benign carcinoma from other more aggressive anal carcinomas that may be strikingly similar histologically.
REPORT OF A CASE
An 82-year-old woman who was hospitalized on the gastrointestinal service for a large gastric ulcer was referred to the dermatology clinic in February 1977 with a large posterior perianal ulcer. It was mildly pruritic and had been present for an unknown period of time. She denied any previous roentgenographic therapy to the area.On physical examination a 3- × 4-cm, sharply marginated "kissing" lesion with a firm white border and ulcerated erythematous center was noted just posterior to the anus; it involved the posterior perianal skin and extended onto the medial buttock bilaterally (Fig 1). Anoscopy and a rectal digital examination were normal. An esophagogastroduodenoscopy
Kraus EW. Perianal Basal Cell Carcinoma. Arch Dermatol. 1978;114(3):460-461. doi:10.1001/archderm.1978.01640150088033