Desmoid tumours in the surveillance era: What are the remaining indications for surgery?

The treatment of desmoid tumours (DTs) has greatly evolved in recent years, and surgery is no longer considered a first-line treatment. Percutaneous biopsy with molecular analysis for beta-catenin or APC gene mutation provides a certain diagnosis. After imaging, a specialized multidisciplinary tumour board (MDT) addresses the following therapeutic strategy. As more than half of patients stabilize or regress, despite initial progression, active surveillance is offered to most patients as the first option. Surgery is proposed for complications such as perforation and occlusion, which sometimes are the first manifestations of the disease. In these cases, limiting surgery to the treatment of complications and leaving the tumour in place is possible if significant bowel sacrifice is needed, especially in patients with previous colectomy for polyposis. Medical therapy is discussed by the MDT in cases of functional or life-threatening masses and is preferred to local treatments that could be mutilating and often incomplete. First-line surgery is now contraindicated in cases of incomplete unplanned surgery, recurrence, pregnancy or DTs occurring in familial adenomatous polyposis(FAP). The best indications of second-line surgery are significantly progressing disease when morbidity is acceptable, such as parietal locations. Medical and other locoregional treatments (radiotherapy, isolated limb perfusion and cryotherapy) should be considered by the MTB when surgery might cause sequelae.

A 28-year-old man visited Peking Union Medical College for a tangible abdominal mass without abdominal pain or distention. Considering the imaging characteristics and clinical manifestation, this mass was primarily diagnosed as GIST before surgery. During the surgery, the occupancy was found under the ileocecal mesentery, with grayish white appearance, tough texture, and poor mobility, which was not consistent with the character of the GIST. After the surgery, pathological examination and individual immunohistochemistry results demonstrated that the lesion was compatible with the diagnosis of retroperitoneal fibromatosis with purulent inflammation of chronic lymphadenitis. Therefore, we decided to perform tumor mass resection, right colon resection, partial duodenum resection, and intestinal anastomosis on laparotomy, but the right ureter was retained. After excision of the tumor, the ends of the intestine segment were continuously sutured. The patient experienced no intraoperative or postoperative complications, and was discharged 3 days after surgery. Periodic follow-up physical examinations such as the abdominal ultrasound and computed tomography were performed each 3 months, and no evidence of recurrence was observed during the whole 12 months.

Desmoid tumors are a manifestation of familial adenomatous polyposis (FAP), associated with mutation of the APC gene. Although considered benign tumors, desmoids can be aggressive and cause considerable morbidity. Known risk factors for desmoid tumor growth include location of mutations within the APC gene, family history of desmoid tumors, previous surgery, female gender, and pregnancy. Desmoids occur at diverse sites, commonly within the abdomen or at sites of previous surgery; thoracic desmoids are relatively uncommon. Reported here is a highly desmoid tumor-prone FAP family with a truncating mutation in the APC gene at codon 1550 (c.4648G>T) in which female siblings developed remarkably similar thoracic desmoids with highly aggressive tumor behavior during the onset of puberty, throughout adolescence, and in one sibling during and following pregnancy. Both siblings had a fatal outcome. This case underscores the potential for aggressive behavior of desmoids during adolescence and the need for close vigilance during the adolescent and young adult (AYA) age range in desmoid-prone FAP kindreds.

A 42-year-old female patient with a history of cervicothoracic junction meningioma World Health Organization grade I, resected in early 2011, was admitted to the hospital with intractable headache and lower extremity weakness. Magnetic resonance imaging (MRI) showed an epidural mass compressing the spinal cord at the prior surgical site, which was interpreted as recurrent meningioma. Following surgical resection, histopathological analysis revealed desmoid fibromatosis (desmoid tumor). In retrospect, dynamic contrast-enhanced magnetic resonance imaging performed prior to surgery should have allowed for prospective exclusion of meningioma as the recurrent mass and suggested an alternative diagnosis such as post-traumatic desmoid fibromatosis or the need for biopsy to confirm diagnosis.

A 36-year-old man was admitted to hospital for a right thyroid nodule incidentally discovered on a chest computed tomography scan for a rib fracture. He had no history of radiation to the head and neck, no known family history of endocrine disease, and no medical or surgical history. A 17 × 10?mm, well-demarcated, multinodular, whitish nodule with neither necrosis nor hemorrhage was found in the right thyroid. Microscopically, the tumor consisted of epithelial cell nests with oval, plasmacytoid or polygonal cells with speckled chromatin, inconspicuous nucleoli and granular cytoplasm. The surrounding stroma showed amyloid deposition and prominent spindle cell proliferation with myxoid substance. Epithelial cell nests showed an immunoreactive pattern for typical medullary thyroid carcinoma (MTC), and the spindle cell stroma showed nuclear expression of beta-catenin. This may be the first report on histopathologic findings of MTC with desmoid-type fibromatosis. Further studies are necessary to discover the clinicopathologic characteristics and pathogenesis of this rare type of tumor.

This systematic review aims to evaluate the efficacy of low-dose chemotherapy with methotrexate and vinblastine for patients with extra-abdominal desmoid-type fibromatosis. We searched the pertinent literature from January 1990 to August 2017. The search yielded 40 studies, 9 of which were included after the first and second screenings. There were three prospective case series but no randomized controlled trials among the nine studies. There was no case-control report (vs. no treatment). According to Response Evaluation Criteria in Solid Tumors criteria, the mean response rate (complete remission or partial response) was 36% (11-57%). Including stable disease, namely, clinical benefit was consistently as high as 85% (69-100%). Mean adverse event rate of G3 or G4 according to CTCAE was 31%. One study reported improvement of pain (87.5%) because of this chemotherapy. The efficacy of this chemotherapy was convincing. However, the overall evidence was weak, and this chemotherapy is not covered by insurance in Japan; we only weakly recommend low-dose chemotherapy with methotrexate and vinblastine in patients with extra-abdominal desmoid-type fibromatosis.