Folliculosebaceous cystic hamartoma presenting as a subcutaneous nodule on the thigh

Folliculosebaceous Cystic Hamartoma Mimicking Preauricular Sinus Cyst

Folliculosebaceous cystic hamartoma (FSCH) is a rare cutaneous hamartoma that consists of follicular, sebaceous, and mesenchymal elements. These lesions are mostly seen on the central face and scalp of adults and mostly present as single 0.5-1.5 cm papules or exophytic nodules. A 17-year-old female patient presented at our clinic with the complaint of swelling, pain and discharge in front of the left ear, which had been recurrent since childhood. The lesion was clinically suspected to be an infected preauriculer sinus cyst. After the medical treatment, the patient was operated on with a pre-diagnosis of preauricular sinus cyst. Histopathological findings revealed FSCH. To the best of our knowledge, this is the first reported case of FSCH originating from the preauricular region, located subcutaneously.

Intracranial epidermoid cyst with proliferative folliculosebaceous epithelium: Report of a rare case and discussion on pathogenesis

Intracranial epidermoid cysts are rarely known to increase in size over a brief period. While malignant transformations of epidermoid cyst have been previously described, no reports to date have described rapid proliferation accompanied by mature hair follicles and sebaceous glands without malignant transformations. The present case involved a 71-year-old man who visited a local physician with disturbance of equilibrium. A mass lesion was detected at the left cerebellopontine angle and was subsequently removed. Histopathological diagnosis of this lesion was as an epidermoid cyst. Seventeen years after this initial surgery, worsened left hypoacusis, disorientation, eating disorder and gait disturbance appeared, and the patient visited the physician again. Local recurrence of the lesion was observed, and the patient was referred to our hospital for its removal. Intraoperative findings revealed a pearly white tumor, histopathologically diagnosed as an epidermoid cyst. Three years later, local recurrence was observed, and the cyst was again removed. Intraoperative findings revealed a partially pearly white tumor similar to the tumor observed during the second surgery, but the majority of the tumor was non-shiny, ochre-colored and suckable. Histopathological diagnosis was an epidermoid cyst with an epidermis-like structure. Postoperative activities of daily living were independent thereafter, but from March of the following year, he began to experience increasing difficulty in walking and subsequently visited our hospital again. Tumor recurrence was observed and was removed again in November of the same year. Intraoperative findings revealed a tumor that was primarily ochre-colored, non-shiny, brittle and suckable. The histopathological diagnosis was folliculosebaceous epithelial proliferative lesion accompanied by an epidermis-like epithelium and a differentiation into hair follicles and sebaceous gland,s and the tumor was determined to be an epidermoid cyst with proliferative folliculosebaceous epithelium.