Sebaceous cyst does not occur in the ...................................

• Epidermoid cyst results from proliferation of epidermal cells within a circumscribed space of dermis (which had got implanted within the dermis) • Sebaceous cyst is a misnomer as the cysts are not of sebaceous origin and the white creamy material filled within is not sebum, but is keratin (desquamated epithelial cells) • Type of retention cyst (secretions are pent up in a gland owing to blockage of the duct) Pathology • Cyst wall consist of a layer of epidermis oriented with the basal layer superficial and more matured layers are deep. • Desquamated cells (keratin) collect in the centre and form creamy substance of the cyst. Clinical Features • Usually asymptomatic, unless get infected or inflamed and become painful • Firm, round, flesh colored to yellow or white subcutaneous nodules of variable size. • Central punctum may teether the cyst to the overlying epidermis, from which the white creamy material can be expressed. • Rarely malignancies (BCC, SCC) can develop in epidermoid cyst. • No punctum in scrotal and scalp sebaceous cyst. Treatment • Excision with the wall is treatment of choice. • Infected cyst: Incision and drainage (After resolution of the abscess, cyst wall must be excised to prevent recurrence)