[Desmoid tumor in familial adenomatous polyposis]

Desmoid tumors (DT) are rare benign tumors that do not metastasize, but tend to invade locally. DT are frequently seen in patients with familial adenomatous polyposis (FAP), and diagnosis and treatment are often difficult.

The article presents the clinical picture, diagnosis and treatment of DT in patients registered in the Danish Polyposis Register by the end of 1999.

Twenty-seven of 486 patients (6%) had DT. Eighteen patients were alive at the time of evaluation. DT were found in the mesentery in 42%, in the abdominal wall in 40%, in the retroperitoneum in 8% and only 10% on the extremities. Fifty percent of the patients had complications (intestinal obstruction, hydronephrosis or fistulas), and 2/9 deaths were caused by DT. Ninety-three percent were treated with surgery, NSAIDs, antioestogenic drugs, chemotherapy or radiotherapy, but all modalities proved disappointing, except for treatment with a combination of the NSAID sulindac and tamoxifen. Five patients treated with this combination showed extensive and long lasting response.

Surgical excision is recommended in patients with DT in the abdominal wall. First line treatment of mesenteric DT is Clinoril in combination with tamoxifen. Elective surgery may be considered in patients with a small well-defined DT with no signs of invasion of vital structures, and in patients with imminent bowel ischaemia or obstruction. The prognosis for mesenteric DT is grave, and improvement of the therapeutic strategy awaits current international studies.