An Unusually Encountered Folliculosebaceous Cystic Hamartoma Clinically Resembling an Epidermal Inclusion Cyst

Folliculosebaceous cystic hamartoma (FSCH) is a rare cutaneous hamartoma comprising epithelial and mesenchymal components. It typically appears as slow-growing, skin-coloured nodules on the face and scalp. We report a case of a mid-forties male with a 4 mm nodule on his left temple, initially thought to clinically represent an epidermal inclusion cyst (EIC). Excisional biopsy results identified the lesion as FSCH, characterised by its unique dilated infundibulocystic configuration with radiating sebaceous lobules and associated mesenchymal elements. FSCH can be misdiagnosed for EIC due to similar clinical presentations but has distinct histological features. Surgical excision is the standard treatment, and the patient has remained recurrence-free since the procedure. This case underscores the importance of considering FSCH in the differential diagnosis of particularly facial and scalp nodules.