RESUMO
BACKGROUND: Bowenoid papulosis occurs primarily on the genitalia of young adults and this is characterized by multiple, apparently benign maculopapular lesions. Bowenoid papulosis shows the histopathological findings of a squamous cell carcinoma in situ, but it follows a largely benign clinical course. If it is misdiagnosed as malignant tumor, unnecessary excessive therapy may be performed. Therefore, exact recognition of this entity is important. OBJECTIVE: The purpose of this study is to examine the clinical and histopathologic features and outcomes of Bowenoid papulosis. METHODS: Twelve patients who had been diagnosed with Bowenoid papulosis between June 1996 and September 2007 were reviewed clinicopathologically. RESULTS: The mean age of the patients was 34.8 years (range: 23~57 years), and the mean duration of Bowenoid papulosis until presentation was 6.3 months (range: 5~48 months). Nine patients were males and 3 patients were females. Eleven patients (92%) had multiple lesions. The average size of the individual lesions was 1.4x0.6 cm in diameter. The colors of the papules were red to black. Seven of 9 male patients had lesions on the penile shaft, with 6 of those occurring at the proximal shaft. The other 2 male patients had lesions on the scrotum and perianal area, respectively. Three female patients had lesions on the labium major, labium major and clitoris, and perianal area respectively. Nine patients (75%) presented without symptom and 3 (25%) presented with mild pruritus. The histopathologic features were as follows: a rete ridge of approximately equal length and breadth throughout the entire lesion (100%), skipped areas of normal keratinocytes between zones of atypical keratinocytes (100%). necrotic keratinocytes (92%), parakeratosis (83%), mitotic figures (83%), vacuolated cells resembling owl's eyes (83%), multinucleated cells (67%), residual changes of typical condyloma acuminatum (17%), involvement of acrotrichia (100%) and involvement of acrosyringia (100%). Eleven patients were effectively treated with surgical excision (8 patients), CO2 laser (2 patients), diphenylcyclopropenone (DPCP) and immunotherapy (1 patient) and 1 patient underwent biopsy only. We followed 12 patients for an average 78.1 months (from 24 to 137 months). During this period, no recurrence or malignant transformation was observed. CONCLUSION: Bowenoid papulosis shows a form of squmaous cell carcinoma in situ for its histopathology, but it hardly ever progresses to squmaous cell carcinoma. On our long term follow-up, there was no malignant transformation. Thus, excessive treatment of Bowenoid papulosis by amputation of the external genitalia is not necessary. Therefore, a through understanding of the clinical and histopathologic features of this entity is necessary for making the diagnosis, the treatment planning and determining the prognosis.