Percutaneous Microwave Ablation of Desmoid Fibromatosis [Full Article]

To demonstrate the feasibility of percutaneous microwave ablation in desmoid fibromatosis with respect to tumor volume control and improvement in the quality of life. Twelve microwave ablations were performed in 9 patients with a histological diagnosis of desmoid fibromatosis between January 2010 and January 2019. The study population included 6 female and 3 male, with an age range of 21-76 years (mean = 46.6 years; standard deviation [SD] = 19.3 years). The mean major axis of the tumors was 10.9 cm (SD = 5.2 cm) and mean lesion volume was 212.7 cm³ (SD = 213 cm³). Their anatomical distribution was as follows: 3 lesions in the thigh, 2 in the gluteus, 2 in the leg and 2 in the periscapular region. We evaluated the reduction in tumor volume and improvement in the quality of life based on the Eastern Cooperative Oncology Group (ECOG) scale. An average tumor volume reduction of 70.4% (SD = 24.9) was achieved, while the quality of life (ECOG scale) improved in 88.9% of patients. Percutaneous microwave ablation may potentially be a safe, effective, and promising technique for controlling tumor volume and improving the quality of life in patients with desmoid fibromatosis.

Introduction and importance: Desmoid fibromatosis is a benign monoclonal fibroblastic tumor that was first reported in 1832 and arises from musculoaponeurotic structures. It is an uncommon tumor that can mimic breast carcinoma in both hits clinical and radiological presentation. This entity mainly affects patients in their fourth and fifth decades of life. Case presentation: Our four patients were of young women in their 2nd and 3rd decade that consulted for masses of the breast. These lesions were suspicious for malignancy in both their clinical and radiological features despite not having any family history of breast carcinoma. Clinical discussion: Only histology provides the diagnosis, it is locally invasive, non-metastatic but with a high potential of recurrence and the sole treatment is complete and wide local excision with clear margins. Conclusion: Although it is a rare clinical scenario, the presence of an unusual breast or chest wall tumor such as a desmoid tumor should be considered when obvious breast changes and history do not correlate with routine diagnostic measures.

Sinonasal myxoma (SNM) is a rare benign mesenchymal tumor that arises in the sinonasal cavity or maxilla and almost exclusively affects young children. Currently, it is considered a specific entity, but its molecular characteristics have not been reported. Lesions diagnosed as SNM and odontogenic myxoma/fibromyxoma (OM/OFM) were identified from the participating institutions, and the clinicopathologic features were recorded. Immunohistochemistry for β-catenin was performed on all cases with available tissue. Next-generation sequencing (NGS) was performed on all SNM cases. Five patients with SNM were identified, including 3 boys and 2 girls with an age range of 20-36 months (mean: 26 months). The tumors were well-defined, centered in the maxillary sinus, surrounded by a rim of woven bone, and composed of a moderately cellular proliferation of spindle cells oriented in intersecting fascicles in a variably myxocollagenous stroma that contained extravasated erythrocytes. Histologically, the tumors resembled myxoid desmoid fibromatosis. Three tested cases showed nuclear expression of β-catenin. In 3 tumors, NGS revealed intragenic deletions of APC exons 5-6, 9 and 15, or 16, respectively, with concurrent loss of the other wild-type copy of APC, predicted to result in biallelic inactivation. The deletions were identical to those that occur in desmoid fibromatosis, and copy-number analysis raised the possibility that they were germline. In addition, one case showed possible deletion of APC exons 12-14, and another case exhibited a CTNNB1 p.S33C mutation. Ten patients with OM/OFM were identified, including 4 women and 6 men (mean age: 42 years). Seven tumors involved the mandible, and 3 the maxilla. Histologically, the tumors differed from SNM, and all cases lacked nuclear expression of β-catenin. These findings suggest that SNM represents a myxoid variant of desmoid fibromatosis that often arises in the maxilla. Because the APC alterations might be germline, genetic testing of the affected patients should be considered.

We report a case of a relatively large desmoid fibromatosis that responded completely to tamoxifen as a single drug therapy. A 47-year-old Japanese man underwent laparoscopy-assisted endoscopic submucosal dissection for a duodenal polyp. He developed postoperative generalized peritonitis and underwent an emergency laparotomy. Sixteen months after the surgery, a subcutaneous mass was found on the abdominal wall. Biopsy of the mass revealed estrogen receptor alpha-negative desmoid fibromatosis. The patient underwent total tumor resection. Two years after the initial surgery, he was found to have multiple intra-abdominal masses, with the largest mass measuring 8 cm in diameter. Biopsy revealed fibromatosis, as in the case of the subcutaneous mass. Complete resection was impossible due to the proximity of the duodenum and superior mesenteric artery. Tamoxifen was administered for three years, resulting in complete regression of the masses. No recurrence was observed for the following three years. This case indicates that relatively large desmoid fibromatosis can be successfully treated with a selective estrogen receptor modulator alone and that its effect is not dependent on the estrogen receptor alpha status of the tumor.

We report the case of a young, healthy soldier with chronic diarrhea and progressively worsening abdominal distention that began during his deployment to Honduras who was subsequently found to have a large intra-abdominal desmoid tumor. Desmoid tumor is a rare and benign neoplasm that typically appears on the extremity, abdominal wall, intra-abdominal space, and occasionally in the chest wall. This tumor may be associated with abdominal distension and gastrointestinal complaints. A large tumor can compress organs, causing local tissue damage and, in rare cases, death.

Desmoid-type fibromatosis (DF) is a locally aggressive but non-metastatic (myo)fibroblastic neoplasm. A hallmark of the tumor is nuclear positivity for beta-catenin in immunohistochemistry due mostly to CTNNB1 mutations. However, a recent study has reported that even beta-catenin ‘nuclear-negative’ DFs can harbor CTNNB1 mutations and that the positive ratio of nuclear beta-catenin in DF is different among antibodies. Here, we reviewed soft tissue lesions for which the possibility of DF was considered and compared the sensitivity and specificity of nuclear beta-catenin for the diagnosis of DF among commonly used anti-beta-catenin antibodies, i.e., clone beta-catenin 1, 17C2 and 14. We analyzed 26 cases of DF, 28 cases of benign fibroblastic lesions, and 27 cases of other soft tissue tumors. The sensitivity and specificity of nuclear beta-catenin for the diagnosis of DF were different among antibodies; 54% and 98% in clone beta-catenin 1, 85% and 84% in 17C2, and 96% and 62% in 14. IHC of LEF1 showed comparable results with IHC of beta-catenin, with a sensitivity of 88% and specificity of 76%. Additionally, when beta-catenin 1 was used, DFs showed characteristic dotted cytoplasmic staining, often appearing as rings. Our results might be helpful for making a correct diagnosis of DF.