Cytological Diagnosis and Misdiagnosis of Nodular Fasciitis

BACKGROUND: Nodular fasciitis (NF) is a rapidly growing, self-limiting, subcutaneous nodular cytologic exuberant fibroblastic/myofibroblastic proliferation prone to cytological misdiagnosis. AIMS: This study aimed at finding out the utility of fine needle aspiration cytology (FNAC) from NF patients and to validate the diagnostic features. MATERIALS AND METHODS: The study group comprised 11 cases diagnosed as NF on cytology or subsequent histology. RESULTS: Out of 11 cases, 9 were cytologically diagnosed as NF. Two cases were misdiagnosed as sarcoma as proven histologically. Of the 9 cases of NF, spontaneous resolution occurred in 7 cases in 2–16 weeks; excisional biopsy was undertaken in the other 2 cases. CONCLUSION: On cytology, NF reveals hypercellular, polymorphic, dispersed cell population, which is most commonly misdiagnosed as sarcoma. For this reason, FNAC has to be correlated with clinical data and followed up for the anticipated spontaneous regression.