Steatocystoma 1_0513 Derm Dx
Steatocystoma 2_0513 Derm Dx
Steatocystoma 3_0513 Derm Dx
A 50-year-old black male presents with lesions on his arms, chest and neck. He first noticed several lesions around puberty and he has progressively developed more lesions over the years. His father has an identical condition.
A biopsy of a lesion is performed, and a cyst draining a viscous and oily liquid is removed.
Submit your diagnosis to see full explanation.
Steatocystoma multiplex is a condition in which the patient develops multiple yellowish cysts containing an oily viscous material. The cysts – termed steatocystomas – are located mainly on the ventral arms, axilla, neck, thigh and anterior trunk. In severe cases, however, the entire body surface area may be affected except the palms and soles. Rarely, only the face is affected. Onset is in adolescence to adulthood.
Steatocystomas have a characteristic histological appearance. The lining of the cyst wall contains mature sebaceous glands. Sebaceous glands are the oil producing glands in the skin. This explains why the cysts contain the oily material.
Steatocystoma multiplex is an autosomal-dominantly inherited condition due to mutations in keratin 17. Keratin 17 is expressed in the nail bed, sebaceous glands and hair follicles.
Another condition associated the keratin 17 mutations is pachyonychia congenita type II. In addition to steatocystomas, patients with pachyonychia congenita demonstrate eruptive vellus hair cysts, nail bed hyperkeratosis and natal teeth. It is not understood why some patients with keratin 17 mutations develop only steatocystoma multiplex, whereas others will develop pachyonychia congenita type II.
The treatment of steatocystomas consists of removal by either excising the cyst en mass or by extraction through a small excision. Removal may not be practical in patients with large numbers of lesions. Oral retinoids and laser incision are other reported therapeutic modalities; however, the lesions will eventually recur.
Adam Rees, MD, is a graduate of the University of California Los Angeles School of Medicine and a resident in the Department of Dermatology at Baylor College of Medicine in Houston.
- Bolognia J, Jorizzo JL, Rapini RP. “Chapter 110 – Cysts.” Dermatology. St. Louis: Mosby/Elsevier, 2008.
- James WD, Berger TD, Elston DM et al. “Chapter 29 – Epidermal Nevi, Neoplasms, and Cysts.” Andrews’ Diseases of the Skin: Clinical Dermatology. Philadelphia: Saunders Elsevier, 2006.