Bowen's Disease Histologically Showing Epidermal Sebocytes at the Sites of Spontaneous Regression

Abstract

Although normal-appearing skin among the lesion of Bowen's disease has been thought to represent partial spontaneous regression of the tumor, only a few reports describe the spontaneous regression of Bowen's disease. Herein we report a case of 68-year-old female with a 40×35 mm erythematous patch on her left upper arm. The patient noticed the patch 3 years before seeking treatment. She was initially treated with topical corticosteroids because two biopsies performed in different dermatology clinic did not reveal any malignancy. When we performed a third biopsy, the diagnosis of Bowen's disease was finally established. Histopathological examination of the resected specimen disclosed that foci of atypical keratinocytes were scattered among almost normal-appearing epidermis with a dermal inflammatory infiltrate and fibrosis, which was thought to represent partial spontaneous regression. The characteristic finding was the presence of scattered epidermal nests of sebocytes in the regression areas. Additional biopsies should be considered when a single biopsy failed to demonstrate atypical keratinocytes in a lesion suspected of Bowen's disease. Further cases are needed to evaluate the relation between spontaneous regression and development of intraepidermal nests of sebocytes.