Muir-Torre syndrome

Topic Completed: 2 February 2021

Minor changes: 8 March 2021

Copyright: 2002-2021,, Inc.

PubMed Search: Muir-Torre syndrome [title] colon

Jennifer Findeis-Hosey, M.D.
Raul S. Gonzalez, M.D.
Page views in 2021 to date: 1,286
Cite this page: Findeis-Hosey J, Gonzalez RS. Muir-Torre syndrome. website. Accessed October 28th, 2021.
Definition / general
  • Clinical variant of Lynch syndrome with cutaneous sebaceous neoplasms (including sebaceous adenoma, sebaceoma and sebaceous carcinoma) or keratoacanthomas in addition to visceral malignancies of Lynch syndrome
  • See also Lynch syndrome, sebaceous adenoma: skin, sebaceous carcinoma: skin, breast
Essential features
  • Variant of Lynch syndrome with skin manifestations
  • More common in men
  • Also called Torre-Muir syndrome
  • Sebaceous neoplasms present at mean age of 53 years
  • M:F = 3:2
  • Sebaceous tumors are most common below the neck
  • Colorectal tumors are more commonly located in proximal colon
  • Typically due to germline mutations in a DNA mismatch repair gene: most commonly MSH2 (60 - 90%); may be due to mutation in MLH1 or MSH6
  • May also be due to inactivation through hypermethylation of a DNA mismatch repair gene
Clinical features
  • Skin neoplasm may be presenting lesion 22% of time (J Am Acad Dermatol 1999;41:681)
  • Colorectal adenocarcinoma is prototypical tumor of Lynch syndrome (typically proximal colon); however, patients may develop other low grade carcinomas, including endometrial carcinomas (15%) and genitourinary carcinomas
  • Clinical algorithms include Amsterdam criteria and revised Bethesda criteria
  • Mayo Muir-Torre syndrome risk scoring system assesses whether patients with sebaceous neoplasms are in need of further evaluation for Lynch Syndrome (Genet Med 2014;16:711)
  • Can screen using immunohistochemical testing for loss of mismatch repair protein expression (MLH1, MSH2, MSH6, PMS2) or microsatellite instability testing via PCR
  • Germline genetic testing
Prognostic factors
  • Muir-Torre associated neoplasms tend to be less aggressive than the same tumors in nonsyndromic patients
Case reports
  • 58 year old man with retroperitoneal undifferentiated pleomorphic sarcoma associated with Muir-Torre syndrome (J Cutan Pathol 2013;40:730)
  • Unusual case of hepatocellular carcinoma in noncirrhotic background in Muir-Torre patient (Fam Cancer 2012;11:7)
  • Sebaceous adenoma arising within an ovarian mature cystic teratoma in Muir-Torre syndrome (Ann Diagn Pathol 2012;16:485)
Microscopic (histologic) description
  • Cutaneous tumors demonstrate sebaceous origin or differentiation, including coarsely vacuolated cytoplasm and starry nuclei (mulberry cells) (Arch Pathol Lab Med 2014;138:1685)
  • Muir-Torre syndrome associated sebaceous tumors are often nodulocystic
  • Cystic sebaceous neoplasms have only been reported in patients with Muir-Torre syndrome
  • Colorectal adenocarcinomas tend to have mucinous features, with tumor infiltrating lymphocytes and Crohn-like reaction
Microscopic (histologic) images

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Significant loss of MSH6

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Colon adenoma and colonic mucosa

Positive stains
  • EMA in sebaceous neoplasms
Negative stains
Molecular / cytogenetics description
  • Autosomal dominant inheritance
  • Mutations most commonly in MLH1 or MSH2 mismatch repair genes (3p22.2 and 2p21, respectively)
  • Microsatellite instability is present in approximately 70% of Muir-Torre syndrome associated tumors
  • Germline testing confirms the diagnosis
Differential diagnosis
  • Lynch syndrome:
    • Similar presentation and genetics, except no sebaceous neoplasms
Board review style question #1
Muir-Torre syndrome is considered a clinical variant of what syndrome?

  1. Cowden syndrome
  2. Juvenile polyposis syndrome
  3. Li-Fraumeni syndrome
  4. Lynch syndrome
Board review style answer #1
D. Lynch syndrome

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Reference: Muir-Torre syndrome
Board review style question #2
Which of the following is a typical manifestation of Muir-Torre syndrome?

  1. Cylindroma
  2. Desmoid fibromatosis
  3. Sebaceous adenoma
  4. Trichilemmoma
Board review style answer #2
C. Sebaceous adenoma

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Reference: Muir-Torre syndrome
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