[Recognition of congenital endometrial carcinoma: the importance of family history and investigation of microsatellite instability in the tumour].

Endometrial cancer diagnosed at a relatively young age or in a patient with a medical history of colorectal cancer may be indicative of Lynch syndrome. Four women, aged 43, 60, 41 and 54 respectively, with a family history of endometrial or colorectal neoplasm were examined for microsatellite instability (MSI) in tumour tissue with positive results. Subsequently, a mutation was found in one of the DNA mismatch repair genes. Lynch syndrome, also known as hereditary non-polyposis colorectal cancer (HNPCC), is caused by a germline mutation in a mismatch repair gene and is an autosomal dominant disorder that is characterized by the development of carcinoma of the endometrium and colorectum at a relatively young age. Until recently, recognition of Lynch syndrome was mainly based on an, often incomplete, family history, but today the presence of MSI in tumour tissue can be used to identify patients at risk for Lynch syndrome. A pathologist can contribute to identifying a patient at risk for Lynch syndrome by initiating MSI testing when: (a) endometrial cancer is diagnosed under the age of 50, (b) a combination of endometrial cancer and colorectal cancer is diagnosed under the age of 70.