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

Abstract

Nodular fasciitis is a benign tumor of soft tissues originating from the proliferation of fibroblasts and myofibroblasts, generally developing between the subcutaneous tissue and the underlying muscular layer. Nodular fasciitis predominantly localizes in the upper extremities, trunk, head and neck. Biomolecular and immunohistochemical analyses result essential to demonstrate the benign origin of the process, also confirmed by very low recurrence rate after complete excision, which represents the gold standard for treatment. We report the case of a 36 years-old man who developed a nodular protuberance clinically evident in the upper-left side of the thorax. We further, highlight the main characteristics of this rare neoplasm trough a thorough review of the literature.

Keywords: Mesenchymal tissue; Nodular fasciitis; Soft tissue mass; Ultrasound Magnetic resonance imaging.

Fig. 1

Ultrasound assessment shows an iso-hyperechoic nodular mass of 32 × 18 × 29 mm, partially encapsulated and provided with a median septum (A), with no signs of invasions of surrounding structures (B); itdevelops superficially within sub-fascial layer of left major pectoralis muscle (C), in correspondence with second sternochondral joint. No adenopathies were found in the explored region (D).

Fig. 2

Color Doppler examination reveals weak peripheral signals.

Fig. 3

MRI scan confirms the presence of a circumscribed nodular lesion, tenuously hyperintense compared to adjacent muscular structures in T1-W sequences (A: axial, B: sagittal), inhomogeneously hyperintense in T2-W ones (C) and SPAIR (D), that moreover shows elevated restriction of water diffusion in DWI (E: axial, F: coronal MIP with background signal suppression). It's located within fatty tissue between minor and major pectoralis muscles: no macroscopic local invasion of the adjacent compartments was observed.

Fig. 4

Gross Pathology of nodular fasciitis demonstrates a relatively well-circumscribed lesion, without a clear capsule.

Fig. 5

Histopathological examination (Hematoxylin-Eosin stain, 20X magnification): microscopically striated muscle appeared infiltrated by well-circumscribed nodular proliferation along the fascia. Marginal areas presented more fibrous stroma and the proliferating cells closely remembered immature fibroblasts and myofibroblasts of granulation tissue. There were scattered microhemorrhages between spindle cells and some lymphocytes and sidero-phages. The diagnosis of nodular fasciitis, intramuscular type, was made.