QuestionSBA
QuestionChoice
This is associated with parathyroid hyperplasia, phaeochromocytoma and medullary thyroid carcinoma. It is therefore unlikely to cause hereditary colorectal cancer.
10035016
e
MEN Type IIA
QuestionChoice
This is associated with pancreatic tumours, pituitary adenomas and parathyroid hyperplasia. It is therefore unlikely to cause hereditary colorectal cancer.
10035015
d
MEN Type I
QuestionChoice
This is a syndrome associated with dominant germline mutations of TSG STK11. It is associated with brown freckles on the oral mucosa, palms and soles. It greatly increases the risk of GI cancer due to the formation of multiple polyps. It is not as common as HNPCC and therefore less likely to be the underlying genetic syndrome in this scenario.
10035014
c
Peutz-Jegher’s syndrome
QuestionChoice
This is a less common hereditary cause of colorectal cancer. It increases the risk of duodenal tumours in addition to colorectal cancer. As a part of Gardner’s syndrome, there is also an increased risk of osteomas of the mandible and skull as well as thyroid carcinoma. Lynch syndrome therefore is more likely to be the underpinning cause of this patient’s presentation.
10035013
b
Familial adenomatous polyposis
QuestionChoice
Lynch syndrome (HNPCC) is the most common **hereditary** cause of colorectal cancer, which should be suspected given the young age of the patient. It also increases the risk of pancreatic and endometrial cancer.
10035012
a
Lynch syndrome
Concept
Chapter
2693
6118
Genetic syndromes and Cancer
Topic
225
Oncology and Palliative Care
19406
Lynch syndrome is primarily caused by mutations in one of the mismatch repair (MMR) genes: MLH1, MSH2, MSH6, PMS2, or the EPCAM gene, leading to a higher risk of colorectal, endometrial, and other cancers.
A 40-year-old male has weight loss, abdominal pain and bloody diarrhoea and is diagnosed with colorectal cancer after a positive FIT test and colonoscopy.

He has a significant family history of cancer. His father died of pancreatic cancer at the age of 57 and his aunt died of endometrial cancer at the age of 55.

Which genetic syndrome is the most likely cause of this patient’s presentation?
a