Sebaceomas in a Muir–Torre-like Phenotype in a Patient with MUTYH-Associated Polyposis

Sep 21, 2026

This case report describes a patient with MUTYH-associated polyposis (MAP) who presented with multiple sebaceomas displaying a Muir–Torre-like phenotype. MAP is caused by MUTYH mutations affecting base excision repair of the 8-oxo-G:A transversion, and it is linked to adenomatous polyps and colorectal cancer. Muir–Torre syndrome is a cutaneous phenotype of Lynch syndrome, also increasing colorectal cancer risk via mismatch repair dysfunction. The findings support additional workup and genetic testing when multiple sebaceous neoplasms are present.

LanguageEnglish

CategoryHealthcare

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Pages5

Reading Time13 min

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1. Introduction

2. Case Report

3. Discussion

Case Report Sebaceomas in a Muir–Torre-like Phenotype in a Patient with MUTYH-Associated Polyposis Julia Guarrera 1,*, James C. Prezzano 2 and Kathleen A. Mannava 3 Citation: Guarrera, J.; Prezzano, J.C.; Mannava, K.A. Sebaceomas in a Muir–Torre-like Phenotype in a Patient with MUTYH-Associated Polyposis. Dermatopathology 2024, 11, 124–128. [https://doi.org/10.3390/](https://doi.org/10.3390/)[ ](https://doi.org/10.3390/)dermatopathology11010011 Academic Editor: Gürkan Kaya Received: 18 January 2024 Revised: 11 February 2024 Accepted: 29 February 2024 Published: 4 March 2024 Copyright: © 2024 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license ([https://](https://)[ ](https://)[creativecommons.org/licenses/by/](creativecommons.org/licenses/by/)[ ](creativecommons.org/licenses/by/)[4.0/](4.0/)) . 1 Norton College of Medicine, SUNY Upstate Medical University, Syracuse, NY 13210, USA 2 Fayetteville Dermatology, Fayetteville, NY 13066, USA 3 Department of Pathology & Laboratory Medicine, Department of Dermatology, University of Rochester School of Medicine and Dentistry, Rochester, NY 14620, USA * Correspondence: [guarrerj@upstate.edu](guarrerj@upstate.edu) Abstract: This case report describes a case of a patient with MUTYH-associated polyposis (MAP), who presented with multiple sebaceomas in a Muir–Torre-like phenotype. MAP is caused by mutations in MUTYH, a base excision repair gene responsible for detecting and repairing the 8-oxo-G:A transversion caused by reactive oxygen species. MAP is associated with an increased risk of developing adenomatous polyps and colorectal cancer. Muir–Torre syndrome is a clinical phenotype of Lynch syndrome, which presents with multiple cutaneous sebaceous neoplasms. Lynch syndrome, like MAP, increases the likelihood of developing colorectal cancer but with a different pathogenesis and mode of inheritance. This case demonstrates that in a patient presenting with multiple sebaceous neoplasms, further workup and genetic testing may be indicated, not only for Muir–Torre and Lynch syndrome but also for MAP. Keywords: Lynch syndrome; MUTYH associated polyposis; Muire–Torre syndrome; sebaceoma; colorectal cancer; sebaceous neoplasm 1. Introduction MUTYH Associated Polyposis (MAP) is caused by mutations in the MUTYH gene, which is a base excision repair gene responsible for detecting and repairing the 8-oxo-G:A transversion caused by reactive oxygen species [1] . MAP is inherited in an autosomal recessive pattern and is associated with an increased risk of developing many adenomatous polyps, and subsequently, colorectal cancer [1,2] . Lynch syndrome is another inherited disorder, also referred to as hereditary non-polyposis colorectal cancer. Patients with Lynch syndrome have a higher likelihood of developing colorectal cancer as well as other malignancies, like endometrial and ovarian cancers [3] . Unlike MAP, Lynch syndrome hasan autosomal dominant pattern of inheritance and is caused by a mutation in a mismatch repair gene. Lynch syndrome is also associated with high microsatellite instability [3] . Muir–Torre syndrome is a clinical phenotype of Lynch syndrome, which presents with multiple sebaceous neoplasms on the skin. In this case, we present a patient with MAP, who presented with multiple sebaceomas in a Muir–Torre-like phenotype. 2. Case Report A 67-year-old Caucasian man presented to the dermatology clinic for a routine fullbody skin exam. Upon examination, the patient had two flesh-colored smooth appearing papules, one on the right central forehead and one on the right medial inferior chest. Both lesions appeared to be clinically suspicious for basal cell carcinoma vs. sebaceous hyperplasia. In total, two shave biopsies were performed. In both specimens, histologic examination showed well-demarcated intradermal sebaceous neopl

FAQs

What is the key clinical finding in this case report?

The patient presented with multiple sebaceomas on the skin in a Muir–Torre-like phenotype.

How is MUTYH-associated polyposis (MAP) described in relation to DNA repair?

MAP results from MUTYH mutations affecting base excision repair, particularly repair of the 8-oxo-G:A transversion caused by reactive oxygen species.

What genetic information supported the final assessment?

Genetic testing identified an autosomal recessive colorectal polyposis with a MUTYH p.G396D mutation, one of the common MAP-associated variants.

Sep 21, 2026

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