A Rare Case Report of Fibromatosis (Desmoid Type-Staghorn vessel Pattern) – Anterior Chest Wall

We report a case of desmoid fibromatosis of the anterior chest wall. Deep fibromatosis or desmoid tumour is a low-grade, soft tissue lesion that is notable for its local infiltration and most commonly occurs in the abdomen. Deep fibromatosis of the chest wall is a rare condition. A 17 year old male presented with an anterior chest wall swelling since 2 months, not associated with pain, gradually increasing in size with features of extension into skeletal muscle on radiology. On Fine Needle Aspiration Cytology, it was diagnosed as a spindle cell tumour and a wide local excision of the tumour was done.

A 3-year-old male child presented with a complaint of swelling between the eyebrows for a 4-month duration. He was evaluated and posted for surgery with a provisional diagnosis of a dermoid cyst. Intraoperatively, the lesion was an ill-defined tissue that was firm and gray-white, occupying the deep subcutaneous plane. Complete excision was possible. The histopathological features were suggestive of the desmoid type of infantile fibromatosis. The postoperative period was uneventful. There was no evidence of recurrence at 3-year follow-up.

Desmoid tumors are rare, locally invasive soft-tissue tumors characterized by a heterogeneous clinical course. Currently, there are no FDA approved therapies for the treatment of desmoid tumors, but a number of agents are used off-label along with locoregional interventions, such as surgery. The identification of physicians who treat these patients and the therapies used is rendered challenging by the lack of a current dedicated ICD-10 code for desmoid tumors. This prevents the utilization of resources, such as claims data, that are typically used to characterize treatment preferences.  Recent joint global consensus guidelines recommend an initial active surveillance period followed by a surgical intervention for abdominal wall tumors and systemic therapies for other locations upon progression. However, in practice, U.S. physician treatment preferences remain unclear.Â
SpringWorks Therapeutics, which is developing a gamma secretase inhibitor for the treatment of desmoid tumors, sought to better understand how U.S. physicians currently treat patients with desmoid tumors. We designed a physician survey to assess past and current therapies used along with a series of hypothetical case studies to evaluate future treatment preferences. The goals of the survey included understanding whether physicians preferred a watchful waiting approach to an active intervention as a front-line therapy, which active treatments (i.e., locoregional or systemic therapies) physicians preferred, and whether patient presentation and etiology altered treatment preferences. The results of the case study portion of the survey were presented at the 2020 American Association for Cancer Research Virtual Annual Meeting II and are described below.

In this paper, the aim was to report our experience with three-dimensional reconstruction (3DR) modeling to determine resection and plan the surgical reconstruction in a patient with a desmoid tumor of the chest wall. A 68-year-old, non-smoking man presented at our outpatient department with painless swelling of the right anterobasal chest wall. A thorax-abdomen-brain CT scan revealed homogenous solid tissue with a dense mass measuring 80 mm × 62 mm. The final 3D model was evaluated by the surgical team (three medical doctors), who found the model to be powerful. Based on the results and the accuracy of the model, the multidisciplinary team decided that the tumor was resectable. The patient underwent right anterolateral thoracotomy at the seventh intercostal space, which confirmed the CT scan findings and revealed infiltration of the serratus muscle and medial portion of the diaphragm. A radical tumor en bloc resection with chest wall and diaphragm resection was performed. The full-thickness chest wall and diaphragm defects were reconstructed using two separate biological patches of a porcine dermal collagen implant (Permacol™ Surgical Implant). Postoperative X-ray revealed unremarkable findings; the patient had an uneventful recovery and was discharged 6 days after surgery.

This study aimed to establish a specified magnetic resonance imaging (MRI) signal and size criterion for assessing the response of desmoid-type fibromatosis (DF). This retrospective study included 129 patients with DF who received non-surgical therapy. All patients underwent pretreatment and 6-month-interval follow-up MRI for >3 years (6 follow-up visits). Signal grade and size among three response groups (partial response [PR], stable disease [SD], progression disease [PD]) were compared. The specified signal and size criterion was established, used to assess tumour response at each follow-up, and compared with the reference. The Response Evaluation Criteria in Solid Tumours (RECIST)1.1 criterion at the end of the 3rd year was considered the reference. MRI signals were moderately correlated with size changes (r = -0.56 and -0.41 for T2 grade and contrast-enhanced T1 grade, respectively). Changes in T2 grade and size in the three response groups were significantly different (all p < 0.01). The signal and size criterion accurately predicted 95% of PR patients at 2nd follow-up and 81.2% of PD patients at the 3rd follow-up, while only 13.1% of PR and 56.3% of PD patients were predicted by RECIST1.1. However, the accuracy of the signal & size criterion for predicting SD was lower than that of RECIST1.1. MRI signal is useful in assessing the response of DF. Signal & size criterion can identify patients with PR and PD earlier than RECIST1.1.

To investigate differential imaging features of intra-abdominal desmoid tumors and peritoneal seeding in patients with history of cancer surgery. Thirty-two patients who had a single pathologically proven intra-peritoneal lesion that developed after cancer surgery were enrolled between January 2000 and June 2019. There were 16 desmoid tumors and 16 peritoneal seeding lesions. Portal phase CT and/or 18F-FDG PET findings were analyzed by two radiologists in consensus for the following items: location, size, shape, margin, contour, homogeneity, necrosis, adjacent organ invasion, calcification, intra-lesional fat, peritoneal infiltration, mass effect, and degree of enhancement. Hounsfield units (HU) and maximum standardized uptake values (SUVmax) of the lesions were measured. Desmoid tumors frequently showed well-defined margins (9/16) and smooth contours (12/16), whereas peritoneal seeding had ill-defined margins (13/16) and lobulated contours (11/16) (P = 0.028 and 0.013, respectively). Intra-lesional fat was found more frequently in desmoid tumors (7/16) than peritoneal seeding (1/16) (P = 0.014). Desmoid tumors showed iso-attenuation (13/16) compared to psoas muscle in portal phase, while peritoneal seeding depicted high attenuation (12/16) (P = 0.002). Mean HU was significantly lower in desmoid tumors (64.3) than peritoneal seeding lesions (95.1) (P = 0.001). However, the mean SUVmax of desmoid tumors (4.1) did not significantly differ from peritoneal seeding lesions (5.2) (P = 0.519). Several CT features including iso-attenuation in portal phase and presence of intra-lesional fat can be helpful in differentiating desmoid tumors from peritoneal seeding in patients with history of intra-abdominal cancer surgery.