Extraocular well-differentiated sebaceous tumors with overlying cutaneous horns: four tumors in three patients
Article first published online: 1 JUL 2014
© 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd
Journal of Cutaneous Pathology
Volume 41, Issue 8, pages 650–656, August 2014
How to Cite
Extraocular well-differentiated sebaceous tumors with overlying cutaneous horns: four tumors in three patients., , , , , .
- Issue published online: 28 JUL 2014
- Article first published online: 1 JUL 2014
- Accepted manuscript online: 19 FEB 2014 02:32AM EST
- Manuscript Accepted: 10 FEB 2014
- Manuscript Revised: 3 FEB 2014
- Manuscript Received: 2 DEC 2013
- NTUH. Grant Number: 102-N2231
- cutaneous horn;
- Muir-Torre syndrome;
- sebaceous neoplasm
Sebaceous tumors are adnexal neoplasms showing sebocytic differentiation. They range from benign to malignant and are associated with Muir-Torre syndrome (MTS). Several clinical and histopathological features associated with MTS have been described. Sebaceous tumors with an overlying cutaneous horn are extremely rare.
Hematoxylin and eosin-stained slides were retrospectively reviewed to identify sebaceous tumors with marked hyperkeratosis, a condition that is often associated with cutaneous horns. Clinical correlation and mismatch repair protein immunohistochemical studies were then conducted.
Four tumors from three patients were identified in our archive. Three were classified as sebaceous adenomas, and the fourth was considered as a borderline sebaceous tumor favoring well-differentiated sebaceous carcinoma. All cases showed loss of expression of mismatch repair proteins (three tumors from two patients exhibited lost expression of MSH2 and MSH6, and the fourth exhibited lost expression of MLH1 and PMS2). Additionally, one patient presented characteristic clinical manifestations of MTS, including multiple sebaceous adenomas and visceral carcinomas.
We suggest that extraocular well-differentiated sebaceous neoplasms with overlying cutaneous horns may be an indication of underlying mismatch repair protein deficiency and potential MTS. This distinctive morphology might be an exaggerated combination of other features associated with MTS, i.e. keratoacanthoma-like architecture and extensive holocrine secretion.