Desmoid-type fibromatosis or desmoid tumor (DT) is an uncommon condition characterized by the absence of metastasis and frequent recurrences;1-7 it represents 3% of soft tissue tumors, and affects up to 0.4 per 100,000 of population,1,6 mainly between 6 to 40 years.5,7 DT is constituted by myofibroblasts with normal mitosis and variable local invasion;5-7 it may be progressive with recurrences or stable with spontaneous regression; watchful waiting approach is indicated in DTs of limbs or girdles.1-7 Radiotherapy, high-intensity focused ultrasound (MRgFUS), and surgery are therapeutic tools.1-8
A 50-year-old man was admitted in 2015 with swelling in the left shoulder and forearm (Figure 1) and local pain with evolution of five years. He denied fever or weight loss, and was tobacco smoker and alcohol abuser for 30 years. In 2011, local examination showed a mass adhered to deeper planes, and biopsy studies were unspecific. The positron emission chest tomography (PET-CT) showed hypermetabolic lesion (8.7 cm, standardized uptake values: 3.9) in the left supra and infraclavicular regions (Figure 1B). Repeated biopsy revealed fibro adipose tissue without atypia. Immunohistochemistry showed mature adipose tissue and positive antibodies: CD3, CD20 and S100; whereas BCL2, AE1AE3, CD34 and CD31 were negative. Magnetic resonance (MRI) on admission (Figure 1C) showed a low signal heterogeneous mass (12×11×8 cm) with heterogeneous enhancement, compression of vasculo-nervous bundle, and involving the subscapular muscle. PET-CT showed increased mass and uptake compared with previous images (Figure 2A and B). Routine laboratory tests and tumor markers CA 19.9, CA 125, CEA and CA15.3 were unremarkable in 2013 and 2015. A third biopsy in 2015 showed fusocellular proliferation indicative of a low-grade mesenchymal tumor. Immunohistochemistry revealed a myofibroblastic lesion with the markers KI67 and AML positive; whereas EMA, S100, AE1AE3, CD34, desmin, and MUC-4 were negative. The surgery was postponed due to lung thromboembolism and lower limb deep venous thrombosis. Further control by MRI showed increased mass (Figure 2C and D), and the biopsy detected a fusocellular proliferation of low nuclear grade and infiltrative growth with characteristics of aggressive fibromatosis (Figure 3C and D). The surgery occurred in June 2016, and showed infiltrated brachial plexus, and pericardium, pleura, and mediastinum involvement. Limb amputation (Figure 2E) was the option. The patient is under thoracic surgery follow-up.
DT of upper extremity herein described evolved six years with local pain and swelling. Diagnostic pitfalls were non-specific initial histopathologic data, and biopsy confirmed DT.5 Because of difficult management of DTs, the best surgical procedure is not consensual; 1-7 the aggressive invasiveness of soft tissues led to the left upper limb amputation in this case.9 Houdek et al. studied 52 DTs of upper limbs followed by more than two years with 57% of 5-year diseasefree. Radiotherapy increased the period of recurrence, but not disease-free time.2 Machado et al. reviewed predictive factors of recurrences and treatment in 51 cases of fibromatosis with seven years of mean follow- up.3 DTs of limbs or deep sited were more aggressive and recurrences did not depend on free margin or non-invasive control.3 Prudinger et al. reviewed prognostic factors for recurrence-free survival after surgery for DT of extremity in 27 patients with mean followup of 64 months.9 Fourteen had adjuvant radiotherapy, which reduced the recurrences of the extremity tumors.9 Peng et al. evaluated clinicopathologic data and treatment of 211 cases of DT to identify factors of recurrences. 6 The median size of tumors was 7.5 cm, in limbs (32%), abdomen, and thorax. Surgical margins were free in 60% of cases, the 5-year recurrence-free survival was 52.8%, and adverse factors were younger age and extra-abdominal site.6 Postoperative recurrences in 5 years occurred in 60% of cases.6 Santti et al. evaluated 41 patients with DT treated by radiotherapy and the significant response was 55%.7 The progression had no relationship with previous surgery or surgical margin.7 Tang et al. reviewed 21 patients with surgical resections of DTs with mean size of 10.5 cm aiming to preserve vital structures of shoulder girdle. The recurrence rate was 9.5%, the mean follow-up was 49.8 months, and 14.3% of complications.10 Ver Halen reviewed 67 resections of DT with median tumor size of 9.8 cm in extremities (40%), thorax, head and neck, and trunk.11 The 5-year recurrence-free survival was 73% for chest, abdomen and upper limb, and resection was not at expense of function preservation. 11 Avedian et al. evaluated MRgFUS for more than 12 months in five cases of failures of treatment of DTs in popliteal fossa, buttock, posterior ankle and chest wall, and there was 36% of decrease in tumor size.8 Prudinger et al. reviewed recurrence-free survival after surgery of extremity DTs in 27 cases followed by 64 months, and radiotherapy improved 14 of them.9