Nodular fasciitis mimicking a soft tissue sarcoma – A case report

INTRODUCTION: Nodular Fasciitis, also known as infiltrative or pseudosarcomatous fasciitis, is a benign soft tissue tumour of fibroblastic/myofibroblastic differentiation, that was first described in 1955 by Konwaler et al. PRESENTATION OF CASE: This is a case report of a 27-year old male with complaints of a swelling in the right axilla for 2 and ½ years measuring 12 cm × 10 cm. Chest X-Ray was normal. Magnetic Resonance Imaging of the right arm and chest showed an irregular mass in the axilla in the muscular-subcutaneous plane measuring 10.8 cm × 8.8 cm × 12 cm, with no neural involvement. Magnetic Resonance Angiogram showed feeders from the branches of the Right Subclavian and Right Axillary Artery and venous drainage into the Right Subclavian Vein. USG guided biopsy was done which showed benign spindle cell neoplasm. Patient underwent wide local excision under general anesthesia. The specimen was sent for histopathological examination which showed histological and immunohistochemical features in favour of Nodular Fasciitis. DISCUSSION: Most nodular fasciitis lesions are solitary and occur in adults 20–40 years of age. Nodular fasciitis affects both men and women with equal frequency. Differential diagnosis of nodular fasciitis includes, fibrosarcoma, fibroma, fibrous histiocytoma, and desmoids and histopathology and immunohistochemistry play a key role in identifying the condition. CONCLUSION: Owing to the size, location and findings of the Magnetic Resonance Angiogram we initially suspected a Soft Tissue Sarcoma, but to our surprise, on further investigation the mass was revealed to be Nodular Fasciitis.