Clinicopathological study of 47 cases of sebaceoma.
BACKGROUND
Sebaceoma is a rare and poorly understood form of sebaceous tumour, and it is of great significance since it may reveal Muir-Torre syndrome (MTS). Herein, we present a series of cases with details of the histopathological appearance.


METHODS
We examined records of cases labelled as sebaceous tumour recorded at the Strasbourg Dermatopathology Laboratory between 1991 and 2015. We include cases of benign sebaceous tumour predominantly involving immature basophilic cells. The clinical and histological data were collected as well as screening for a history of MTS.


RESULTS
We studied 47 cases of sebaceomas (26 men), in patients of mean age 67.6years, located primarily in the head or neck (32 cases). Of the 17 patients followed up, 6 had MTS. Different types of architecture were seen: dermal nodule (9 cases) or cystic nodule (9 cases), multiple dermal nodules (22 cases), exophytic tumour (4 cases) and an appearance intermediate with sebaceous adenoma (3 cases). The cells involved were basophilic, with the presence of round ducts exhibiting an eosinophilic cuticle and, in rare cases, mature sebocytes. Mitoses were observed: mean 6.6/10 fields (0 to 19). In all cases, there was expression of CK17, EMA and androgen receptors, but not of BerEP4.


CONCLUSIONS
Sebaceoma is a small benign tumour but identification is imperative due to association with MTS. A knowledge of the associated cytological and architectural elements - particularly cysts and labyrinthine patterns - and immunolabelling enable differential diagnosis with respect to other tumours. The extra-facial and cystic forms in particular require screening for MTS. If there is any doubt, immunolabelling of androgen receptors provides a precious tool.
Clinique dermatologique, faculté de médecine, université de Strasbourg, hôpitaux universitaires de Strasbourg, hôpital civil, 1, place de l'Hôpital, BP 426, 67091 Strasbourg cedex, France.
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Bourlond
Clinique dermatologique, faculté de médecine, université de Strasbourg, hôpitaux universitaires de Strasbourg, hôpital civil, 1, place de l'Hôpital, BP 426, 67091 Strasbourg cedex, France. Electronic address: charles.velter@gmail.com.
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Velter
Clinique dermatologique, faculté de médecine, université de Strasbourg, hôpitaux universitaires de Strasbourg, hôpital civil, 1, place de l'Hôpital, BP 426, 67091 Strasbourg cedex, France.
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B
Cribier
D000236:Adenoma / Q000473:pathology*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008297:Male; D053842:Microsatellite Instability; D008875:Middle Aged; D055653:Muir-Torre Syndrome / Q000150:complications / Q000175:diagnosis; D012626:Sebaceous Gland Neoplasms / Q000473:pathology*
Adénome sébacé; Glande sébacée; Muir-Torre syndrome; Sebaceoma; Sebaceous adenoma; Sebaceous gland; Sebaceous tumour; Syndrome de Muir-Torre; Sébacéome; Tumeur sébacée