Giant Protruding Nodular Fasciitis of the Anterior Chest Wall Clinically Mimicking a Soft Tissue Sarcoma

Abstract

Nodular fasciitis (NF) is a benign reactive proliferation of myofibroblasts that predominantly occurs subcutaneously. Commonly, it presents as a rapidly growing swelling in 4-8 weeks. NF mostly occurs in adults aged 20-50 years and usually has a diameter<3‐4 cm. Giant NF with a diameter>4 cm is rare. Owing to its rapidly growing nature, a precise clinical diagnosis is difficult; it is frequently misdiagnosed as an aggressive or malignant tumor. Herein, we present the case of a 15-year-old male who presented with a large protruding mass on the anterior chest wall. The tumor appeared clinically malignant as it was protruding and had doubled in size within a few weeks, reaching approximately 8×6 cm. Furthermore, the tumor separated and fell off spontaneously due to its large size. As the remaining tumor continued to grow rapidly, surgery was performed. Following wide tumor resection, no recurrence, metastases, or other complications were noted 1 year postsurgery. NF was diagnosed after pathological evaluation, including immunohistochemical analysis, molecular genetic testing, and cytogenetic testing via fluorescence in situ hybridization analysis. Knowledge of the atypical clinical course and a combination of histopathological examinations are necessary to accurately diagnose NF.

A case of nodular fasciitis that was difficult to distinguish from sarcoma

“…It sometimes shows spontaneous regression [6] and recurrence is rare, even after incomplete excision [2], with no reports of malignant transformation. These lesions may show atypia and mitoses, making nodular fasciitis difficult to distinguish from sarcoma [5,[7], [8], [9]]. In fact, Plaza et al [10] reported that two thirds of their cases were misdiagnosed as sarcoma.…”

Nodular fasciitis of the anterior chest wall mimicking myxofibrosarcoma: A case report and literature review

“…With the rare exception of giant nodular fasciitis [6 , 7] , dimensions are usually below 3-4 centimeters [7] ; history of previous trauma can be referred in a low percentage of cases (10%) [8] .…”

“…Nodular fasciitis may occur in every part of the body, presenting elective localization in the upper extremities and trunk [2 , 7 , 14] , as well as head and neck [15 , 16] - the latter, recognizes a particular involvement of infants and children [1] .…”