Case report – 34-year-old women presented to the fertility clinic at university hospital Monklands, Scotland, UK with unexplained primary infertility for 2 years. During the workup, the transvaginal ultrasound showed a thickened endometrium of 14 mm, saline infusion sonography suggested the possibility of an endometrial polyp measuring 13X11 mm in size. She denied any history of heavy menstrual or inter-menstrual bleeding. Hysteroscopic polypectomy and endometrial biopsy was preformed, and the result revealed a complex endometrial hyperplasia in places amounting to endometroid adenocarcinoma FIGO grade 1. Genetic testing for the biopsy sample showed loss of nuclear staining for MSH6 which is consistent with the diagnosis of Lynch syndrome.

She had a family history of colon cancer. Her mother had colon cancer at the age of 42. Her sister is under colonoscopic surveillance for bowel polyps.

Management options were offered, including fertility sparing treatment and surgery (Total hysterectomy and Bilateral salpingoophrectomy) and she opted for surgery.

A Total laparoscopic hysterectomy and bilateral salpingoophrectomy and washing cytology was performed. Pathology results were consistent with well differentiated endometroid adenocarcinoma stage 1A and peritoneal washing showed no malignant cells. 

Referred to colorectal surgeons and colonoscopy showed no abnormality apart from mucosa ulceration in the terminal ileum therefore, according to British society for gastroenterology guideline for 2 yearly colonoscopic surveillance. 

Discussion - In this case the main presentation was infertility, on reviewing literature there was no evidence that Lynch syndrome is associated with infertility.  Around 3% of endometrial cancer are hereditarily related to Lynch syndrome. The old screening criteria would recommend screening women with endometrial cancer below the age of 50 for Lynch syndrome which ultimately led to missed cases of Lynch syndrome. The recent changes in the NICE guideline, 2020 recommended screening all patients regardless of their age and family history for Lynch syndrome when resources are permitted.

Conclusion – This case represents atypical presentation of Lynch syndrome. Therefore, it is essential to have a systematic approach for managing gynecology patients. A Detailed family history is the key in identifying patients requiring screening for Lynch syndrome.