Metachronous cutaneous squamous cell carcinoma in a young patient as the only presenting symptom to uncover Lynch syndrome with MLH1 Germline mutation

Clinical factors associated with skin neoplasms in individuals with Lynch syndrome in a longitudinal observational cohort

BACKGROUND

Little is known about patient-specific risk factors for skin neoplasia in individuals with Lynch syndrome (LS).

OBJECTIVE

Identify clinical factors associated with development of skin neoplasms in LS.

METHODS

Clinical data were systematically collected on a cohort of LS carriers (confirmed pathogenic germline variants in MLH1, MSH2, MSH6, PMS2, or EPCAM) age ≥18 undergoing clinical genetics care at Dana-Farber Cancer Institute from January 2000 to March 2020. Multivariable logistic regression was performed to evaluate clinical factors associated with skin neoplasia.

RESULTS

Of 607 LS carriers, 9.2% had LS-associated skin neoplasia and 15.0% had non-LS-associated skin neoplasia; 58.2% (353/607) had documentation of prior dermatologic evaluation; 29.7% (38/128) with skin neoplasms lacked a history of visceral LS-associated malignancy. LS-associated skin neoplasms were significantly associated with male sex, age, race, MLH1 pathogenic germline variants, MSH2/EPCAM pathogenic germline variants, and personal history of non-LS skin neoplasms. Non-LS-associated skin neoplasms was significantly associated with age, number of first- and second-degree relatives with non-LS-associated skin neoplasms, and personal history of LS-associated skin neoplasms.

LIMITATIONS

Single-institution observational study; demographic homogeneity.

CONCLUSIONS

Skin neoplasms are common in individuals with LS. We identified clinical factors associated with LS- and non-LS-associated skin neoplasms. Regular dermatologic surveillance should be considered for all LS carriers.

Cutaneous Squamous Cell Carcinoma in Lynch Syndrome - An Overlooked Association

Lynch syndrome is an autosomal dominant disorder caused by germline mutation affecting mismatch-repair genes. Genetic testing is performed selectively. Diagnosed individuals are to undergo surveillance to detect and manage Lynch syndrome-related cancers early in the course.

Muir-Torre syndrome is a phenotypic variant of Lynch syndrome characterized by sebaceous neoplasms, keratoacanthoma, or both in addition to other Lynch syndrome-related cancers. Other neoplasms of the skin, such as squamous cell carcinoma, are not recognized as part of the Lynch syndrome tumor-spectrum. We report a case of cutaneous squamous cell carcinoma occurring in a patient with Lynch syndrome and explore some of the characteristic features and significance of this association.