Folliculosebaceous Cystic Hamartoma: A Rare Entity

Abstract

Folliculosebaceous Cystic Hamartoma (FSCH) is an uncommon cutaneous hamartomatous lesion. It is basically a tumour like malformations exhibiting abnormal overgrowth of biphasic elements i.e., epithelial and mesenchymal components that are normally found in the skin. Few other hamartomas of pilosebaceous origin are trichofolliculoma, trichodiscoma, fibrofolliculoma and pilar sheath acanthoma. Though distinct, this entity shares similar histological features to Sebaceous Trichofolliculoma (STF). Hence, a proper histological examination is must in differentiating it from STF and other clinical and histological entities. Authors hereby, describes a case of FSCH in a 37-year-old male who presented with a slow growing cystic mass on his left earlobe, an uncommon location for such lesion. The mass was excised, and a detailed histological evaluation showed a characteristic multinodular growth pattern with lobules of pilosebaceous glands forming nodules around cystically dilated follicular infundibular structures. No hair shafts were seen in the cystic cavity ruling out differential diagnosis of sebaceous hyperplasia which could have been a close mimic. The intervening stroma revealed dense collagen, sheets and lobules of adipocytes, many vascular channels filled with fibrinous deposits. Perivascular adipocytes were also noted along with few nerve tissues (perineurium). A detailed clinicopathological work-up helped in arriving at a final diagnosis of FSCH with neural component. The patient was doing well till last six months of follow-up. No recurrence of similar lesion was noted in the patient.

Keywords

• hamartomatous lesion
• histopathology
• pilosebaceous unit
• sebaceous trichofolliculoma