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Sebaceous Adenoma and Sebaceoma

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Cutaneous Adnexal Neoplasms
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Abstract

Sebaceous adenomas and sebaceomas are benign neoplasms with sebaceous differentiation.

Clinically, they present as solitary small yellow papules/nodules in adults most commonly on the face and scalp.

Sebaceous adenomas are neoplasms composed of predominantly mature sebocytes, and sebaceomas are neoplasms composed predominantly of immature germinative sebaceous cells.

Histopathologically, well-differentiated sebaceous adenomas/sebaceomas are composed of multiple sebaceous lobules, resembling normal sebaceous glands and connecting directly with the epidermis or the follicular infundibula through sebaceous ducts. Cystic variants are particularly common in Muir–Torre syndrome.

Less differentiated sebaceous adenomas/sebaceomas are composed of aggregates of predominantly germinative basaloid cells with very little resemblance to lobules of a normal sebaceous gland and with a less evident connection with the epidermis.

Immunohistochemically, well-differentiated sebocytes and sebaceous ducts stain positively for EMA and adipophilin, whereas germinative sebaceous cells stain for hTERT and the nonspecific markers CK56 and CK15.

Muir–Torre syndrome is a rare autosomal dominant genodermatosis characterized by cutaneous sebaceous proliferations and visceral malignancies. Sebaceous adenomas in these patients often show high degree of microsatellite instability. Antibodies against mismatch repair proteins including MSH2, MSH6, MLH1, and PMS2 may be used as a first step in ruling out the possibility of Muir–Torre syndrome.

Surgical removal of sebaceous adenoma/sebaceoma is curative. The most important fact is to rule out the possibility of Muir–Torre syndrome.

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Requena, L., Sangüeza, O. (2017). Sebaceous Adenoma and Sebaceoma. In: Cutaneous Adnexal Neoplasms. Springer, Cham. https://doi.org/10.1007/978-3-319-45704-8_68

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