Background: Pilomatricoma is a rare, benign adnexal tumor differentiating toward elements of the hair matrix and shaft. It typically presents as a solitary, deep, dermal nodule. In addition, bullous changes can be rarely seen. Methods: A 16-year-old girl with firm, mobile, multilobule and non-tender mass that has a soft, hemorrhagic blister-like formation on the left infraclavicular region is described. Results: The histopathologic findings were consistent with pilomatricoma. In the dermis above the tumor, there were numerous dilated lymphatic and blood vessels. No pathologic elastic fibrils were identified with elastin stains. Collagen fibrils were normal with Mason trichrome stain. Conclusions: The patient is diagnosed as pilomatricoma with bullous appearance.

Background: Pilomatricoma is a rare, benign adnexal tumor differentiating toward elements of the hair matrix and shaft. It typically presents as a solitary, deep, dermal nodule. In addition, bullous changes can be rarely seen. Methods: A 16-year-old girl with firm, mobile, multilobule and non-tender mass that has a soft, hemorrhagic blister-like formation on the left infraclavicular region is described. Results: The histopathologic findings were consistent with pilomatricoma. In the dermis above the tumor, there were numerous dilated lymphatic and blood vessels. No pathologic elastic fibrils were identified with elastin stains. Collagen fibrils were normal with Mason trichrome stain. Conclusions: The patient is diagnosed as pilomatricoma with bullous appearance.