Familial adenomatous polyposis and desmoid tumors

A case report of desmoid tumour—a forgotten aspect of FAP?

“…Desmoid tumours are rare fibromatous lesions that are non-metastasising but locally aggressive and have a high rate of recurrence even after complete resection [1], [2] These slow-growing tumours commonly arise in the abdominal wall or in the intra-abdominal region.…”

“…Whereas the incidence of desmoid tumours in the general population is 2–4 per million per year, the incidence in FAP is 10–20%, meaning that a patient with FAP is at an 852-fold increased risk of developing a desmoid tumours [2], [3], [6]. While sporadic desmoid tumours show a flight female preponderance, there is an equal incidence in males and females in FAP patients [8].…”

“…FAP is characterized by hundreds of adenomatous colorectal polyps, with an almost inevitable progression to colorectal cancer at an average age of 35–40 years [4]. Biallelic mutations of the APC gene induces desmoid tumour formation, hence the association between these two disorders [2]. Surgical trauma has been identified as a predisposing factor for desmoid tumour formation in FAP, with one key study from 1994 noting a history of previous abdominal surgery in 68% of FAP patients with abdominal desmoids, with 55% occurring within 5 years post-operatively [7].…”

“…This may result in intestinal obstruction, ischemic bowel secondary to vascular compression, and hydronephrosis due to ureteric compression. Desmoid tumours can also rarely lead to bowel perforation as well as deep vein thrombosis, pyrexia of unknown origin, gastrointestinal bleeding and intra-abdominal abscess formation [2].…”

“…CT and MRI are used to identify these tumours (and monitoring) [2] but a biopsy is necessary to confirm the diagnosis [1]. They are initially kept under observation while their size remains sTable Surgical excision with a safety margin is the first-line treatment for enlarging desmoid tumours.…”