Colon
Syndromes
Muir-Torre syndrome
Last author update: 2 February 2021
Last staff update: 8 March 2021
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PubMed Search: Muir-Torre syndrome [title] colon
Table of Contents
Definition / general | Essential features | Terminology | Epidemiology | Sites | Etiology | Clinical features | Diagnosis | Prognostic factors | Case reports | Microscopic (histologic) description | Microscopic (histologic) images | Positive stains | Negative stains | Molecular / cytogenetics description | Differential diagnosis | Additional references | Board review style question #1 | Board review style answer #1 | Board review style question #2 | Board review style answer #2Cite this page: Findeis-Hosey J, Gonzalez RS. Muir-Torre syndrome. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/colontumormuirtorre.html. Accessed December 11th, 2024.
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
Terminology
- Also called Torre-Muir syndrome
Epidemiology
- Sebaceous neoplasms present at mean age of 53 years
- M:F = 3:2
Sites
- Sebaceous tumors are most common below the neck
- Colorectal tumors are more commonly located in proximal colon
Etiology
- 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
Diagnosis
- 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
Images hosted on other servers:
MSH2+
Significant loss of MSH6
Colon adenoma and colonic mucosa
Positive stains
- EMA in sebaceous neoplasms
Negative stains
- Loss of MSH2 and MSH6 staining in colonic polyps (Arch Dermatol 2006;142:1039)
- CK15 and MSH2 in sebaceous neoplasms (J Cutan Pathol 2006;33:634, Dermatol Online J 2006;12:4, Am J Clin Dermatol 2007;8:315)
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
Additional references
Board review style question #1
Muir-Torre syndrome is considered a clinical variant of what syndrome?
- Cowden syndrome
- Juvenile polyposis syndrome
- Li-Fraumeni syndrome
- Lynch syndrome
Board review style answer #1
Board review style question #2
Which of the following is a typical manifestation of Muir-Torre syndrome?
- Cylindroma
- Desmoid fibromatosis
- Sebaceous adenoma
- Trichilemmoma
Board review style answer #2
