Desmoid Tumours in Familial Adenomatous Polyposis: Review of 17 Patients from a Portuguese Tertiary Center

Unraveling the Mystery of Desmoid Tumors: Insights From a Moroccan Tertiary Center

Desmoid tumors (DTs) are rare, aggressive malignancies developing from clonal fibroblastic proliferation originating from soft tissues. Despite their low metastatic potential, their invasiveness towards neighboring organs and a high recurrence rate contribute significantly to morbidity and mortality, thereby impacting the quality of life of patients. Several therapeutic options are available, but standardized protocols are lacking. In this study, we reviewed 14 cases of DT retrospectively over a period of 15 years, from September 2008 to December 2023. The most prevalent tumor locations were in the extremities, and the majority of patients were female. We identified risk factors in two patients, those being surgical trauma and familial adenomatous polyposis (FAP). Half of the patients underwent surgery for DT, and two received salvage radiotherapy. Systemic therapy was used in the first and second lines and comprised of chemotherapy, endocrine therapy, and non-steroidal anti-inflammatory drugs (NSAI). Active surveillance was proposed in three patients. This is the first retrospective study to assess the characteristics of DT in Moroccan patients in a tertiary care setting. It aims to shed light on the challenges faced in treating these rare tumors in the context of a lack of therapeutic standardization.

Familial adenomatous polyposis associated with desmoid tumors presenting with abdominal abscess: A case report and literature review

RATIONALE

Familial adenomatous polyposis (FAP) associated with desmoids tumors (DTs) complicated by abscess formation is rare. The management is not easy and the choice of the best treatment may be controversial.

PATIENT CONCERNS

A 33-year-old man was admitted to our hospital for abdominal pain, fever, chills, nausea, and vomiting. He had a family history of FAP, and history of abdominal surgery.

DIAGNOSES

An abdominal enhanced chest computed tomography (CT) scan revealed a soft tissue mass in the abdominal wall and an irregular mesenteric soft tissue mass with internal fistula and intra-abdominal abscess. A CT-guided biopsy of the abdominal wall mass revealed DTs.

INTERVENTIONS

The patient was given oral antibiotics for 6 months, and ultimately underwent surgery.

OUTCOMES

The patient had no evidence of recurrence on follow-up at 10 months.

LESSONS

This case indicates that for patients with FAP who have a history of abdominal surgery and a progressively enlarging mass and abscess in the abdomen, it is necessary to consider the possibility of DTs. FAP-related DTs are rarely complicated by abscess formation. Antibiotic therapy plus surgical resection of the tumor may be effective and make good prognosis.

The Management of Desmoid Tumors: A Retrospective Study of 30 Cases

Objectives

Desmoid tumor also called aggressive fibromatosis is a rare type of benign tumor. It is a mesenchymal malignancy without metastatic potential. The standard management is resection, but other options including observation may be discussed. Desmoid-type fibromatosis may occur throughout the body, but the abdominal wall is the most common site. The aim of our study was to assess the clinicoepidemiological profile, prognostic factors, and treatment outcome of desmoid tumors.

Methods

A monocentric retrospective study was conducted over a period of 19 years between February 2000 and November 2019 at the oncology department of Salah Azaïz Institute. Our study concerns 30 patients with desmoid tumor. All data regarding patients were obtained from the medical record.

Results

Thirty patients were included. The median age was 35 years with a female predominance (sex ratio = 0.07). A palpable mass was the most common complaint (n = 27). Median tumor size was 5 cm. The principal site of involvement was the abdominal wall (n = 14). Surgery was performed in 27 patients. The histopathology reports listed 14 (52%) cases with negative margins and 13 (48%) cases with positive margins. Radiation therapy was performed in 2 patients. One patient received tamoxifen. Local recurrence occurred in 11 patients. Two patients died of their desmoid tumor. Abdominal wall tumors have less risk of recurrence compared with other sites (p=0.047). Macroscopic margin involvement (R2) was the only prognostic factor influencing disease-free-survival (p=0.034).

Conclusion

Desmoid tumors are aggressive tumors with a tendency for local recurrence. Abdominal wall tumors have less risk of recurrence. Macroscopic margin involvement was the only prognostic factor that affects disease-free-survival.

Radiotherapy in the treatment of aggressive fibromatosis: experience from a single institution

Background

Desmoid-type fibromatosis is a rare, potentially locally aggressive disease. Herein we present our experience in the treatment with radiotherapy.

Methods and materials

In total 40 patients who received 44 treatments from 2009 to 2018 at the Heidelberg University Hospital with photons (N = 28) as well as protons (N = 15) and carbon ions (N = 1) were investigated. The median age at radiotherapy was 41 years [range 8–78]. Familial adenomatous polyposis (FAP) was confirmed for nine patients and 30 had a unifocal desmoid tumor. The localizations were abdominal wall, abdominopelvic cavity, thoracic wall, extremity, head and neck and trunk. The median prescribed dose was 54 Gy/ Gy (RBE) [range 39.6–66, IQR 50–60]. Eleven treatments were performed at the time of first diagnosis; 33 at the time of progression or recurrence. Post-operative radiotherapy was performed in 17 cases. The median planning target volume was 967 ml [84–4364 ml, IQR 447–1988]. Survival analysis was performed by the Kaplan-Meier Method.

Results

The median follow-up time was 32 months [1–153]. At the end of the follow-up interval all patients but one were alive. The estimated local progression free survival of the treated lesion in 3 and 5 years was 76.4% and 63,8%, respectively. The progression-free survival in 3 and 5 years was 72.3 and 58.4% and the overall survival was 97.4 and 97.4%, respectively. In case of macroscopic tumor (N = 31) before radiotherapy a partial remission was observed in 12 cases (38.7%) and a complete remission in 4 cases (12.9%). Progression was observed in 13 (29.5%) cases, predominantly at the margin of the planning target volume (PTV, N = 5, 38,4%) followed by progression within the PTV (N = 4, 30.8%). In univariate analysis multifocal localization was associated with impaired progression-free survival (p = 0.013). One patient developed a grade V gastrointestinal bleeding, otherwise no acute toxicity >°III was observed. Late toxicity was depending on the localization of the desmoid tumor and was especially severe in patients with FAP and abdominopelvine desmoids including gastrointesinal fistula, perforation and abscess.

Conclusion

Radiotherapy in the treatment of desmoids can lead to long term control. Treatment of patients with abdominopelvine desmoids should be avoided, as the risk of higher-grade complications is substantial.

An unusual finding in a desmoid-type fibromatosis of the pancreas: a case report and review of the literature

Background

Desmoid-type fibromatoses are rare benign and fibrous tumors that account for approximately 0.03% of total neoplasms. Within this category of neoplasms, pancreatic desmoid-type fibromatosis is an extremely rare subgroup, accounting for approximately 5% of desmoid-type fibromatoses. Although the etiology is unknown, some risk factors include trauma, surgery, family history of desmoid tumor, pregnancy, use of contraceptives, genetic mutation, and familial adenomatous polyposis or Gardner syndrome. Desmoid-type tumors are primarily diagnosed by pathological and immunohistochemical studies. The treatment of choice is surgical resection of the tumor. Systemic chemotherapy and radiotherapy are optional treatment approaches for patients with high risk for surgery.

The following is a report of an unusual case of a pancreatic desmoid-type fibromatosis in which a very rare variation in the immunohistochemistry findings was demonstrated: slides were immunopositive for S100 protein and not immunonegative. Most desmoid tumors are immunonegative for S100 protein with just a few cases being positive for this protein.

Case presentation

We describe the case of a 15-year-old boy, a Chinese national, who was diagnosed as having a pancreatic desmoid-type fibromatosis. He was a healthy individual who was incidentally diagnosed with an abdominal mass. His chief complaints were mild generalized abdominal pain for 1 week, nausea, vomiting, and a low-grade fever. An enhanced computed tomography scan of his abdomen showed a large cystic mass in the anterior surface of the body of his pancreas. He underwent a radical resection of the pancreatic mass, partial pancreatectomy, splenectomy, segmental resection of transverse colon and distal jejunum, and subsequently a one-stage jejunojejunostomy and colonic anastomosis. Postoperatively, he was diagnosed as having a desmoid-type fibromatosis of the pancreas by pathological and immunohistochemical studies.

Conclusions

The diagnosis of desmoid-type fibromatosis is usually incidental and challenging. Pathological and immunohistochemical testing are essential for confirming diagnosis where demonstration of β-catenin nuclear staining is probably the single most important characteristic. Other markers, such as vimentin, are usually positive, while S100 protein is usually negative. Our case however, confirms that there are rare cases that can be S100 positive. This is the first diagnosed case of pancreatic desmoid-type fibromatosis with S100 protein positivity.

Recurrent Enlarging Mesenteric Desmoid Tumor following Remote Surgical Resection

Intra-abdominal desmoid tumors are commonly associated with genetic syndromes such as familial polyposis coli. Radiological cross imaging studies such as CT and MRI are used in the preoperative work-up of such tumors. Postoperatively, CT and MRI are useful in the assessment of recurrent desmoid tumors. MRI is more accurate in tissue characterization. Where possible, surgical resection remains the standard first-line treatment. For patients where surgery is not possible, or the resection margins are not clear, other forms of treatment are possible. These include hormonal and nonhormonal options. We present a case of a recurrent sporadic intra-abdominal (mesenteric) desmoid tumor. Such an entity is rare with few cases reported in the literature. Treatment options regarding intra-abdominal desmoid tumors will be discussed.