MTS follows an autosomal dominant pattern of inheritance in the majority of cases. One reported subtype of MTS may follow an autosomal recessive pattern. MTS may also occur sporadically or present in transplant recipients or immunocompromised populations. It also has a high degree of penetrance but variable expression. MTS occurs in both sexes, but in the literature, there is a male-to-female ratio of about 3:2. Patients may present at any age, from childhood to old age, but most patients with MTS are discovered in middle age, with a median age of about 50 years.
Clinical diagnostic criteria for MTS include one or more of the following (Mayo Muir-Torre syndrome risk score algorithm). Risk score ranges from 0-5; a risk score of 2 or more has a sensitivity of 100% and specificity of 81% for predicting a germline mutation in MMR genes:
- Younger than 60 years at first diagnosis of sebaceous neoplasm (1 point)
- Presence of one or more sebaceous neoplasms (0 points for one; 2 points if 2 or more)
- Personal history of Lynch-related malignancy (1 point)
- Family history of Lynch-related malignancy (1 point)
C18.9 – Malignant neoplasm of colon, unspecified
403824007 – Muir-Torré syndrome
- Sebaceous neoplasms can occur in isolation unrelated to any genetic syndrome, and the same holds true for keratoacanthomas.
- Gardner syndrome is an autosomal dominant form of familial adenomatous polyposis (FAP) that presents with polyposis of the colon, an increased risk of colorectal malignancy, osteomas, and other cutaneous manifestations such as epidermoid cysts. It does not involve specifically sebaceous neoplasms as does MTS.