Giant solitary sebaceous gland hyperplasia clinically simulating epidermoid cyst.

We report an unusual case of sebaceous gland hyperplasia manifested clinically as a large solitary intracutaneous nodule, which was at first diagnosed as an epidermoid cyst. Histologically, the nodule consisted of a single large central cavity connected with numerous fully-matured sebaceous glands. We discuss the unique clinical appearance and its histopathological differential diagnosis including sebaceous adenoma, sebaceous trichofolliculoma, organoid nevus and sebaceous gland hyperplasia.