Evolving strategies for management of desmoid tumor

Desmoid tumors (DTs) are rare soft tissue mesenchymal neoplasms that may be associated with impairments, disfigurement, morbidity, and (rarely) mortality. DT disease course can be unpredictable. Most DTs are sporadic, harboring somatic mutations in the gene that encodes for β-catenin, whereas DTs occurring in patients with familial adenomatous polyposis have germline mutations in the APC gene, which encodes for a protein regulator of β-catenin. Pathology review by an expert soft tissue pathologist is critical in making a diagnosis. Magnetic resonance imaging is preferred for most anatomic locations. Surgery, once the standard of care for initial treatment of DT, is associated with a significant risk of recurrence as well as avoidable morbidity because spontaneous regressions are known to occur without treatment. Consequently, active surveillance in conjunction with pain management is now recommended for most patients. Systemic medical treatment of DT has evolved beyond the use of hormone therapy, which is no longer routinely recommended. Current options for medical management include tyrosine kinase inhibitors as well as more conventional cytotoxic chemotherapy (e.g., anthracycline-based or methotrexate-based regimens). A newer class of agents, γ-secretase inhibitors, appears promising, including in patients who fail other therapies, but confirmation in Phase 3 trials is needed. In summary, DTs present challenges to physicians in diagnosis and prognosis, as well as in determining treatment initiation, type, duration, and sequence. Accordingly, evaluation by a multidisciplinary team with expertise in DT and patient-tailored management are essential. As management strategies continue to evolve, further studies will help clarify these issues and optimize outcomes for patients.

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Background: Desmoid fibromatoses are rare, benign neoplasms of myofibroblast origin that lack metastatic potential but can be locally invasive. Diagnosis and management are challenging as these are based on a multitude of factors such as symptomatology, tumor location, risk of recurrence, and the possibility of treatment-induced morbidity. Case Presentation: A healthy 48-year-old Filipino woman presents with an 2×3 cm incidental jejunal mesenteric mass found intraoperatively during the excision of her choledochal cyst. Histopathology of the core-needle biopsy revealed desmoid fibromatosis. An initial watchful waiting approach was employed since the patient was asymptomatic and resection would cause significant bowel loss. After three months, her abdominal CT scan shows that the mass had progressed, to 4.7 x 4.5 x 4.7cm. Anti-hormonal therapy with high-dose Tamoxifen (120mg daily) was initiated due to its limited toxicity and low cost. The patient is currently asymptomatic, on her sixth month of treatment. The tumor remained stable at 4.5 x 4.6 x 4.7cm, on repeat abdominal imaging. Conclusions: Desmoid fibromatosis represents a benign histology with a malignant and unpredictable course. It warrants a multidisciplinary team approach upfront. Watchful waiting is an appropriate first line option, especially in asymptomatic tumors and those found in non-critical locations. In case of progression, management should be site specific and via a stepwise approach. Therapeutic toxicities, such as significant intestinal loss upon resection, should be carefully weighed before choosing treatment. Preferred management for patients with intra-abdominal desmoid tumors that progress after observation has shifted towards non-surgical approaches or systemic therapies, including antiestrogens, NSAIDs, tyrosine-kinase inhibitors (sorafenib, pazopanib and imatinib) and chemotherapy (methotrexate and vinblastine, and vinorelbine). A stepwise escalation of therapy from less to more toxic agents are a reasonable approach. It is also possible to discontinue treatment and resume watchful waiting for patients not progressing for two years

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An 80-year-old man was referred to our hospital because of epigastric pain. Abdominal computed tomography revealed a well-defined circular intra-abdominal mass in the gastro-pancreatic region measuring 15 mm in diameter. After 6 months, the mass lesion was growing with mild enhancement, and weaker enhancement was found in the lower half of the mass on contrast-enhanced computed tomography. The mass lesion touched the stomach, whereas adipose tissue appeared to intervene between the mass and pancreas. On magnetic resonance imaging, the well-defined mass lesion had isointensity to muscle on T1-weighted imaging, slight hyperintensity to muscle on T2-weighted imaging, which indicated a rich fibrous tumor. Under general anesthesia, the patient underwent open surgery. Intraoperatively, the tumor was separated from the stomach and firmly attached to the pancreas. Therefore, we performed a distal pancreatomy with splenic resection. Pathological diagnosis was desmoid-type fibromatosis in the retroperitoneum, and the tumor margin was attached to the pancreas, splenic artery, and splenic vein. Since there are few reports of desmoid-type fibromatosis occurring in the retroperitoneum of the gastropancreatic region, it is difficult to distinguish from other soft tissue tumors and to identify the tumor origin. Close observation by radiological re-valuation was a useful option. Magnetic resonance imaging signals and an enhanced pattern may help distinguish a desmoid-type fibromatosis from other soft tissue tumors. A desmoid-type fibromatosis that is well-defined in radiological findings may infiltrate the surrounding organs with gross or pathological analyses.

Introduction: Desmoid-type fibromatosis, also known as desmoid tumors, are rare fibroblastic neoplasms that account for less than 3% of all soft tissue tumors. Although they are benign neoplasms without metastatic potential, they are known to be locally aggressive and may invade adjacent structures leading to fatal complications. Case presentation: We describe the case of a 26-year-old woman who presenting with the clinical picture of acute peritonitis. Emergency surgery was performed and a large poorly-circumscribed heterogeneous tumor was found, occupying the jejunum mesentery and infiltrating the jejunal wall causing its perforation into the abdominal cavity. En bloc resection of the tumor and the involved jejunum was performed. Histology and immunohistochemistry confirmed it to be mesenteric desmoid-type fibromatosis. The postoperative course was uneventful and the patient had no evidence of recurrence 18 months after tumor resection. Conclusions: Mesenteric desmoid-type fibromatosis is a rare condition with insidious growth and locally aggressive behavior. Serious complications such as bowel perforation are rare but possible, as shown in our presentation. Complete surgical resection is the first-line treatment bur high recurrence rates remain problematic.