Bowen's disease: statistical study of a 10 year period.

According to histological records, a total of 74 patients were diagnosed with Bowen's disease (B.d.) between 1 January 1984 and 31 December 1993 at the Department of Dermatology of Kitasato University. There was slight female predominance (36 male, 38 female), and 73% of the patients were older than 60 years; the mean age was 66.8 years. Fifteen patients had multiple (two-five) lesions. In 13 patients, other benign skin lesions were also found. Arsenic exposure as etiologic factor could have been present in 2 cases. Only 3 patients had other associated malignant tumors, which does not confirm the paraneoplastic nature of B.d. One-fifth of the lesions were on sun-exposed areas (head, neck and hands). Although we excluded invasive carcinomas from our statistical study, we mention the 8 invasive carcinomas developing from B.d. in that period. Histopathological classification of B.d. is uncommon. Classifying our cases by Darier's histopathological classification, 63.3% of them belonged to the lenticular type. The malignant potential of different histopathological types of B.d. needs further investigation.