Sebaceoma (Sebaceous Epithelioma)

 Autosomal dominant disease due to mutations in mismatch repair genes MLH1, MSH2, MSH6

image Multiple sebaceous tumors including sebaceous adenomas, less likely carcinomas and sebaceomas

Clinical Issues

• Rare tumors; typically occur in adults

• Most common on face

• Usually single but may be multiple, especially in MTS patients


• Nodular, dermal-based adnexal tumor
• Well circumscribed, noninfiltrative

• Composed mostly of basaloid cells

• Minor population of clear cells with multivacuolated cytoplasm, consistent with mature sebaceous cells

image Show nuclear hyperchromasia with indentations

• Basaloid cells may show mild cytologic atypia and increased mitotic figures

• Sebaceous cells do not show significant atypia or mitotic activity

Top Differential Diagnoses

• Basal cell carcinoma with sebaceous differentiation
image Basal cells show greater atypia and peripheral palisading

image Mucinous stroma and retraction artifact often present (lacking in sebaceoma)

• Sebaceous adenoma
image > 50% clear cells

• Sebaceous carcinoma

• Trichoblastoma with sebaceous differentiation

Sebaceoma at Low Magnification
Low magnification of a sebaceoma shows a dermal-based basaloid to clear cell neoplasm with peripheral basaloid cells surrounding clear cells image, sebaceous secretions, and a focal cystic space image.

Sebaceoma at Higher Magnification
Higher magnification of sebaceoma shows a superficial, well-circumscribed lobule of predominantly basaloid cells with a smaller population of bland-appearing, mature sebaceous cells image.

Sebaceoma at High Magnification
High magnification of a sebaceoma shows a population of scattered, bland-appearing, multivacuolated clear cells demonstrating nuclear hyperchromasia and nuclear indentations image, which are due to cytoplasmic lipids.

Cystic Sebaceoma
This is an example of a sebaceoma with cystic areas, which shows a proliferation of predominantly basaloid image and focal clear cells image surrounding the cystic space image.



• Sebaceous epithelioma (older term, should be discouraged)


• Benign proliferation of mature sebaceous cells associated with predominant basaloid cell population


Unknown in Most Cases

• Some cases are part of Muir-Torre syndrome (MTS)
image Autosomal dominant disease due to mutations in mismatch repair genes MLH1, MSH2, MSH6

image Patients present with multiple sebaceous tumors, including sebaceous adenomas (most common), sebaceomas, and sebaceous carcinomas

image Also associated with internal malignancies including gastrointestinal carcinomas (most common), genitourinary, breast, and ovarian tumors

• Rare cases arise in nevus sebaceous of Jadassohn



• Incidence
image Rare tumors

• Age
image Typically occur in adults


• Often occur on face but may also present on trunk


• Slow-growing papular to nodular lesion
image Usually single, but may be multiple, especially in MTS

• Flesh-colored to yellowish


• Surgical approaches
image Complete conservative excision is curative


• Excellent; very low malignant potential
image Possible transformation to sebaceous carcinoma in longstanding lesions

Apr 24, 2017 | Posted by in PATHOLOGY & LABORATORY MEDICINE | Comments Off on Sebaceoma (Sebaceous Epithelioma)

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