|Classification and external resources|
Muir–Torre syndrome (MTS) is a rare hereditary, autosomal dominant cancer syndrome:663 that is thought to be a subtype of HNPCC. Individuals are prone to develop cancers of the colon, breast, and genitourinary tract, and skin lesions, such as keratoacanthomas and sebaceous tumors. The genes affected are MLH1, MSH2, and more recently, MSH6, and are involved in DNA mismatch repair.
Muir-Torre Syndrome is characterized by both:
- At least a single sebaceous gland tumor (either an adenoma, an epithelioma, or a carcinoma)
- A minimum of one internal malignancy
The Amsterdam criteria are frequently used to diagnose Lynch syndrome and Muir–Torre syndrome. They include the following:
- 3 or more relatives with an HNPCC-associated cancer (i.e., colorectal, cancer of the endometrium, small bowel, ureter, or renal pelvis)
- 2 or more successive generations affected by cancer
- 1 or more persons with cancer is a first-degree relative of the other 2, at least 1 case of colorectal cancer younger than age 50 years, a diagnosis of familial adenomatous polyposis has been excluded, tumors are verified by histologic examination
Muir-Torre Syndrome is a genetic condition. Mutations in MLH1 and MSH2 are linked with the disease. These genes code for DNA mismatch repair genes, and mutations increase the risk of developing cancerous qualities.
The 2 major MMR proteins involved are hMLH1 and hMSH2. Approximately 70% of tumors associated with the MTS have microsatellite instability. While germline disruption of hMLH1 and hMSH2 is evenly distributed in HNPCC, disruption of hMSH2 is seen in greater than 90% of MTS patients.
Gastrointestinal and genitourinary cancers are the most common internal malignancies. Colorectal cancer is the most common visceral neoplasm in Muir–Torre syndrome patients.
Immunohistochemistry is now being used more often to diagnose patients likely to have Muir-Torre. Sebaceous neoplasms are only infrequently encountered, and immunohistochemistry is reliable and readily available, so researchers have recommended its use. Routine immunohistochemical detection of DNA mismatch repair proteins help identify hereditary DNA mismatch repair deficiency.
Genetic Overlap with Turcot Syndrome
A couple studies have been conducted on patients with both Muir-Torre Syndrome and Turcot Syndrome. It is thought that the two may have some genetic overlap. Both have been associated defects in MLH1 and MSH2 genes.
In one study, a patient with defective MSH2 and MSH6 mismatch repair genes exhibited both syndromes. This is the first case where a patient with genotypic changes consistent with HNPCC has been properly diagnosed with an overlap of both syndromes. Along with neoplasms of the sebaceous gland, this patient developed cerebral neoplasms, characteristic of Turcot Syndrome.
- List of cutaneous conditions
- List of cutaneous conditions associated with increased risk of nonmelanoma skin cancer
- James, William D.; Berger, Timothy G. et al. (2006). Andrews' Diseases of the Skin: clinical Dermatology. Saunders Elsevier. ISBN 0-7216-2921-0.
- Cohen PR, Kohn R, Kurzrock R. (May 1991). "Association of sebaceous gland tumors and internal malignancy: The muir-torre syndrome". The American Journal of Medicine 90 (5): 606–13. doi:10.1016/S0002-9343(05)80013-0. PMID 2029018.
- South CD, Hampel H, Comeas I, Westman JA, Frankel WL, Chapelle A. (February 2008). "The Frequency of Muir-Torre Syndrome Among Lynch Syndrome Families". Oxford Journal 100 (4): 277–81. doi:10.1093/jnci/djm291. PMID 18270343.
- Ponti G, Losi L, Pedroni M. (October 2006). "Value of MLH1 and MSH2 mutations in the appearance of Muir-Torre syndrome phenotype in HNPCC patients presenting sebaceous gland tumors or keratoacanthomas. |". J Invest Dermatol 126 (10): 2302–7. doi:10.1038/sj.jid.5700475. PMID 16826164.
- Okan G, Vural P, Ince U, Yazar A, Uras C, Saruc M. (August 2012). "Muir-Torre syndrome: a case report and review of the literature". Turk J Gastroenterol 23 (4): 394–8. PMID 22965514.
- Orta L, Klimstra DS, Qin J et al. (2009). "Towards identification of hereditary DNA mismatch repair deficiency: sebaceous neoplasm warrants routine immunohistochemical screening regardless of patient's age or other clinical characteristics". Am J Surg Pathol 33 (6): 934–44. doi:10.1097/PAS.0b013e318199edca. PMID 19342947.
- Graefe T, Wollina U, Schulz H, Burgdorf W. (March 2000). "Muir-Torre Syndrome – Treatment with Isotretinoin and Interferon Alpha-2a Can Prevent Tumour Development". Dermatology 200 (4): 331–3. doi:10.1159/000018399. PMID 10894967.
- Spielvogel RL, DeVillez RL, Roberts LC. (March 1985). "Oral isotretinoin therapy for familial Muir-Torre syndrome". J Am Acad Dermatol 12 (3): 475–80. doi:10.1016/S0190-9622(85)70066-7. PMID 3857234.
- Muir EG, Bell AJ, Barlow KA (March 1967). "Multiple primary carcinomata of the colon, duodenum, and larynx associated with kerato-acanthomata of the face". Br J Surg 54 (3): 191–5. doi:10.1002/bjs.1800540309. PMID 6020987.
- Torre D (November 1968). "Multiple sebaceous tumors". Arch Dermatol 98 (5): 549–51. doi:10.1001/archderm.98.5.549. PMID 5684233.
- Kleinerman R, Marino J, Loucas E. (May 2012). "Muir-Torre Syndrome / Turcot Syndrome overlap? A patient with sebaceous carcinoma, colon cancer, and a malignant astrocytoma". Dermatology Online J. 18 (5): 3. PMID 22630573.
- Grandhi R, Deibert CP, Pirris SM, Lembersky B, Mintz AH. (April 2013). "Simultaneous Muir-Torre and Turcot's syndrome: A case report and review of the literature". Surg Neurol Int. 4 (52): 52. doi:10.4103/2152-7806.110512.