perianal plasmoacanthoma after bcg-immunotherapy: case report and review of literature

Plasmoacanthoma is a rare verrucous tumor classified as a form of reactive plasmacytosis. we present the first reported case of plasmoacanthoma following exposure to bacillus calmette-guérin (bcg) and a comprehensive review of the literature to better illustrate the patients’ characteristics and proposed risk factors, clinical features, diagnosis, treatment, and outcome of current reports. a 64-year-old female presented with a perianal hyperkeratotic plaque and diffused inflammatory macerated erosions in the intergluteal cleft and adjacent to the plaque after intravesical bcg immunotherapy. laboratory studies disclosed systemic abnormalities and local infection or malignancies. biopsy showed intradermal polyclonal plasma cell infiltration with acanthosis. the lesions were successfully treated with carbon dioxide laser ablation followed by the combination of pulsed dye laser and intralesional corticosteroid. diagnosis of cutaneous reactive plasmacytosis should be confirmed by excluding the systemic causes of plasmacytosis and malignancies. it responds well to intralesional corticosteroids; however, in severe cases and large sizes, other treatments such as carbon dioxide laser ablation and pulsed dye laser should be considered as a combined therapy. identification of causative factors is impractical while skin irritants with subsequent inflammation seem to be involved; as in the current report, bcg contact with skin initialized the pathologic process.