Folliculosebaceous cystic hamartoma in a patient with neurofibromatosis type I.

Folliculosebaceous cystic hamartoma (FSCH) is a rare cutaneous hamartoma composed of dilated folliculosebaceous units and mesenchymal elements. It presents as a papule or nodule usually on the face and scalp, rarely on the genital or trunk area. Histologically, FSCH shares several similar features to sebaceous trichofolliculoma. We report one case of FSCH misdiagnosed as a neurofibroma. He was a 38-year-old man with a neurofibromatosis type I and a nodule on his left earlobe was excised under the impression of neurofibroma. Pathological examination revealed FSCH. Although FSCH is clinically not distinctive, awareness of the lesion is important to differentiate papulonodular or cyst-like cutaneous lesions.