REPORT OF A CASE
A 39-year-old white woman presented complaining of a pruritic lesion on her lower abdomen. It had not changed significantly since she noted it 6 months previously. It would occasionally crust over and was intermittently pruritic.Her medical and family history and a review of systems were unremarkable.Cutaneous examination revealed a single 3-mm, wellcircumscribed, erythematous papule with central umbilication on the left lower abdomen just above the belt line (Figure 1). There were no other skin, nail, or mucosal findings.A shave biopsy specimen of the lesion revealed hyperkeratosis, extensive suprabasalar acantholysis, and a superficial dermal round cell infiltrate (Figure 2 and Figure 3).What is your diagnosis?
The solitary acantholytic acanthoma is a benign cutaneous tumor probably seen much more commonly than is reported. First described by Brownstein1 in 1985, his review of 31
Barnette DJ, Cobb M. A Solitary, Erythematous, Hyperkeratotic Papule. Arch Dermatol. 1995;131(2):213-214. doi:10.1001/archderm.1995.01690140097017