Aggressive Fibromatosis of Desmoid Type – a Pictorial Review

Deep fibromatosis of desmoid type comprises rare mesenchymal tumors characterized histologically by proliferation of fibroblasts and myofibroblasts. These lesions are characterized by infiltrative growth and local recurrence but an inability to metastasize. They can be located in the abdominal wall (generally in sutures), intra or extraabdominal. The best imaging modality for evaluation and staging of the deep fibromatoses is MR imaging. These well or ill-defined lesions generally present internal hypointense bands, with lack of enhancement in post contrast images (collagen bundles) and are usually centered in an intermuscular location with a rim of fat (“split fat sign”), although invasion of surrounding muscle is frequent. Linear extension along fascial planes (“fascial tail sign”) is also a frequent manifestation in deep fibromatoses and is uncommon with other soft tissue neoplasms. MR image signal intensity has an implication on tumor recurrence, with a higher recurrence rate in lesions with high T2 signal. In surgically untreated lesions, with undergoing radiation or drug therapy, MR surveillance has been used to assess response to treatment with positive results demonstrating decrease in T2 signal, lesion enhancement and lesion size.

Here, we report the case of a 66-year-old male patient who previously underwent resection of sigmoid colon cancer and its liver metastasis. His follow-up contrast-enhanced CT scan revealed a mass shadow at around the gastrosplenic ligament, which gradually increased in size. Because it could not be pathologically diagnosed by transgastric EUS-FNA, en bloc resection was performed surgically for the tumor in the greater omentum. Hematoxylin-eosin staining of the resected specimen showed fibroblast-like cellswith hyperplasia of bold collagen fibersand spindle-shaped nucleus. While the immunostaining findings denied a diagnosis of mesenchymal neoplasm such as GIST, leiomyosarcoma, or schwannoma, it was pathologically diagnosed as a desmoid tumor. He has been followed up without any recurrence for 2-and-a-half years after the surgical resection. Desmoid tumors tend to be locally invasive; thus, there is the potential for local recurrence, although the frequency of distant metastasis is very low. In cases in which the tumor increases in size, en bloc resection with sufficient surgical margin should be performed. Cases of desmoid tumors originating from the greater omentum are reportedly rare; however, en bloc resection may be useful for both diagnosis and treatment of tumors of the greater omentum showing increased size that are also surgically resectable.

We present the case of a 76-year-old man with no pathological history. admitted in the emergency room due to a 5-day evolution fever associated with abdominal distension and a palpable mass in the hypogastrium.Urgent surgical intervention showed a large tumor of 15×15 cm affecting the jejunum (20 cm from the duodenojejunal angle); intestinal resection was performed with free margins and lateral-lateral mechanical anastomosis was done. Immunohistochemical analysis was negative for CD117, DOG1, ALK1, S100, CD34, desmin and actin and positive for vimentin and beta-catenin, desmoid tumor dependent on the jejunal wall, free neoplasic intestinal margins

We describe the case of a 34-year-old woman who presented with a painful parotid mass. She was found to have an extra-abdominal fibromatosis of her right parotid gland. Medical management with antibiotics and immunosuppression therapy was unsuccessful. Surgical resection was required for both a definitive diagnosis and management. Preoperative findings on computed tomography, magnetic resonance imaging, and both fine-needle aspiration biopsy and surgical biopsy were nonspecific, as is typical in EAF cases.

We reviewed the records of 209 consecutive patients with desmoid fibromatosis treated with RT, either alone or as combined modality therapy (CMT) with surgery, at our institution from 1965 to 2015. Median follow-up time was 98 months (range, 1-509 months). The 5-year and 10-year LC was 71% and 69%, respectively. 59 patients (28%) experienced a local recurrence at a median time of 23 months (interquartile range, 15-38 months). Among all patients, on multivariable analysis, adjusting for anatomic site, size, age, treatment era (>2005 vs. ≤ 2005), treatment approach (RT alone vs. CMT), and an interaction between age and treatment, we found only age ≤30 yrs (HR 2.94, P=0.005, 95% CI 1.38-6.27) and large tumor size >10cm (HR 2.51, P=0.03, 95% CI 1.09-5.78) to be correlated with poorer LC. Notably, for patients receiving RT alone the 5-year LC was 43% for patients ≤30 yrs vs 75% for >30 yrs (P<0.001). On multivariable analyses, for patients receiving RT alone, the only factor associated with inferior LC was age ≤30 yrs (HR 2.87, P=0.001, 95% CI 1.51-5.47). The same was true for patients treated with CMT; age ≤30 yrs was the only factor associated with inferior LC (HR 5.36, P=0.01, 95% CI 1.40-20.58). Among all patients with desmoid fibromatosis, RT is an effective local therapy for tumor control. However, young patients ≤ 30 yrs have notably high rates of local recurrence regardless of treatment strategy, which requires further study. Treatment decisions should be risk-adapted by large referral centers with multidisciplinary expertise in desmoid management.

We present 3 cases of desmoid fibromatosis post pancreatectomy for pancreatic adenocarcinoma. All cases occurred within 3 years of diagnosis of pancreatic cancer, with subsequent extensive diagnostic work-up to rule out metastatic disease. No relationship between pancreatic cancer and desmoid fibromatosis is documented in the literature, with a postulated connection via mutations on the Wnt/APC/Beta-catenin pathway.