INTRODUCTION
Nodular fasciitis (NF) or pseudosarcomatous fibromatosis was first described in 1955 (1) and it is a rare benign condition in which fibroblasts rapidly proliferate from the deep fascia to the adjacent tissues, including muscle and subcutaneous tissue. It is a self-limited, solitary lesion whose pathogenesis is still uncertain. NF seems to be related to local traumas in only 10-15% of cases (2).
In most of the non-traumatic cases recent studies identified rearrangements of the USP6 gene, often with MYH9 (3). In about half patients local tenderness or pain is reported whereas paresthesia and shooting pain is mostly present when NF involves the upper limbs. Given the self-limiting nature of the lesion, the definition of “transient neoplasia” has been proposed (3). NF shows no predilection for gender or race, and affects the upper extremities (43%), the trunk (25%), and head and neck district (10%) in young adults aged 20–40 years (2). Differential diagnosis encloses, fibrosarcoma, fibroma, schwannoma, fibrous histiocytoma, and desmoids. Histopathology and immunohistochemistry play a pivotal role in diagnosis as FNAC might be useful but not conclusive (4,5,6,7). In fact, NF can be correctly diagnosed only if the cytologist is aware of its clinical and cytologic features (8). After proper surgical excision recurrence is very rare (2).