The Landmark Series: Desmoid

Desmoid-type fibromatosis represents a challenge in the landscape of surgical oncology, for several reasons. The tumors can be infiltrative and locally aggressive, surgery may be morbid, and patients are usually young, and thus treatment sequelae must be managed for decades. Desmoids do not have metastatic potential, therefore management strategies for desmoids have evolved to employ frontline treatments that are largely non-operative. In fact, with unpredictable and benign behavior, we now recognize that desmoids can also stabilize and regress, making active observation an option for many patients. Moreover, many medical therapies are active in the disease. We reviewed landmark studies describing contemporary issues that affect treatment recommendations for desmoid patients: prognostic factors, indication to active surveillance, role of surgical margins, postoperative radiotherapy, and the most recent expert consensus papers.

Hereby, we report a case of fibromatosis arising in the left popliteal fossa, proven by histopathology and immunohistochemistry. Local excision of the mass was performed. The patient was asymptomatic for 6 months, after which she complained of difficulty in walking. Clinical evaluation elicited recurrence in the surgical bed. In spite of the surgical excision with tumor-free margins, recurrence was seen within a span of 6 months. 18F-fluorodeoxyglucose (FDG) positron emission tomography-computed tomography (PET/CT) was done to rule out multifocal disease and to define the extent of relapse. Although magnetic resonance imaging provides an excellent soft-tissue resolution to delineate the disease, 18F-FDG PET/CT is an important and supplementary tool which aids in the management of fibromatosis.

Here we report a case of a 41-year-old male patient who underwent resection of a desmoid tumor originating from the greater omentum with no history of open surgery. An elastic hard mass was palpated in the left upper abdomen, but there were no abnormalities on serum chemical tests, including tumor markers. Computed tomography showed a parenchymal tumor located near the descending colon. Integrated positron-emission tomography and computed tomography revealed moderate accumulation of tracer in the tumor. An intra-abdominal malignant mesenchymoma was suspected and surgery was performed. The tumor was located in the anterior portion of the greater omentum. It partially invaded the diaphragm, and the affected regions were concurrently resected. The resected specimen measured 80 mm at longest diameter. The cut surface was grayish white and parenchymal. The histopathological findings showed the atypical spindle shaped tumor cells grown with collagen fiber progression. Immunohistochemical staining for beta-catenin showed strong staining in the nuclei and cytoplasm of tumor cells. The patient was diagnosed with desmoid tumor originating from the greater omentum.

We experienced a case of intra-abdominal desmoid tumors occurring 4 years after open radical prostatectomy with some literature review. A 72-year-old man had undergone open radical prostatectomy for prostate cancer. Four years after that resection, multiple intra-abdominal tumors measuring 56 mm in maximum diameter was identified on follow-up computed tomography, and he was referred to our department for management. We performed laparotomy and investigation of the biopsy. Immunohistochemistry of the resected specimen indicated the tumor cells were positive for vimentin and beta-catenin, and the diagnosis was desmoid. We performed partial resection of the small intestine and ileocecal resection. His postoperative course was uneventful and he was discharged on the 12th postoperative day. He has shown no sign of recurrence in the 4 months follow-up since surgery.

Cryoablation is an interventional radiology technique that is suitable for desmoid tumours (DTs) patients (pts) on the basis of repeated cycles of freezing, leading to cell death. CRYODESMO-01 (ClinicalTrials.gov Identifier: NCT02476305) is a prospective, open-label, non-randomised, non-comparative, multicenter study assessing cryoablation in non-abdominopelvic progressing DT. 50 pts were enrolled (78% female) from four French centres and all were treated. The mean age was 41 y.o. (19-73). The median number of prior treatments was 2.00 [1-4] including non-steroidal anti-inflammatory drugs (NSAIDs), hormone therapy, chemotherapy, and anti-angiogenics. Tumour location included limbs (36%), trunk (60%), and cervical area (4%). The median tumour largest diameter was 89 mm. The rate of non-progressing disease at +12 months was 86% [confidence level (CI) 95% 73-94%]. Median PFS was not reached at a median follow-up of 31 months. Cryoablation significantly improved functional status and pain scores. Cryoablation demonstrated feasibility in progressive DT pts. The study met is primary end-point with 86% of non-progressive disease at +12 months, with reduced pain, better functional status, and encouraging long-term disease control.

The Desmoid Tumor Research Foundation (DTRF) was founded in 2005 with the mission of facilitating and funding research toward a cure for DT and supporting patients with information (staging-dtrforg.kinsta.cloud). The DTRF constantly receives inquiries from healthcare professionals, patients, and family members for advice on the management of DT. Similarly, as is the case for other rare tumors, known experts in the field of DT are inundated with email queries from colleagues seeking guidance. These messages often contain limited information; yet, the recipient typically feels a moral obligation to respond resulting in recommendations that may or may not be appropriate. With the desire to meet the needs of patients with DT and physicians worldwide, the DTRF initially raised the idea with members of its Scientific and Medical Advisory Boards of creating a virtual forum for discussion of complex DT cases. The idea was then taken to the annual DTRF International Research Meeting in 2017 where the virtual tumor board was born. The mission of this virtual tumor board includes four key tenants: multidiscipline, resourceful, inclusive, and collaborative. A core group of committed discipline-specific expert panelists from pediatric and medical oncology, radiology, general and orthopedic surgical oncology, pathology and radiation oncology were identified. A web-based platform was selected with funding and operations provided by the DTRF.