Two Cases of Pilomatricoma with Bullous Appearance

Abstract

Pilomatricoma is a common, benign, cutaneous neoplasm, differentiating towards elements of the hair matrix and shaft. It typically presents as a deep-seated, solitary, firm nodule with overlying normal epidermis. However, pilomatricoma with bullous appearance is very rare. We report two cases of pilomatricoma with bullous appearance. The first case was an 11-year-old male who presented with 6 month history of a soft, erythematous, translucent polypoid mass on the left upper arm. The other case was a 20-year-old female who presented with 12 month history of a soft, slightly-brownish, peduncluated mass with indurated nodules on the left upper arm. In both cases, the histopathologic findings revealed multiple islands of shadow cells, with small foci of basophilic cells at the periphery of the deep dermis. There was dilation of lymphatic vessels in the overlying dermis, which explained the clinical bullous appearance.