Clinicopathological characteristics and favourable prognosis of paediatric cutaneous nodular fasciitis: a case series.

Abstract

Cutaneous nodular fasciitis (cNF) is a rare, benign myofibroblastic proliferation commonly misdiagnosed as a malignancy due to its rapid growth and histological features. We reviewed 15 paediatric patients with cNF, highlighting clinical, histological and molecular characteristics. The patients' median age was 6 years, and there was a predilection for cNF in the head and neck region. Histologically, cNF showed plump spindle cells and myxoid stromal changes. USP6 rearrangement, particularly MYH9-USP6 fusion, was present in the majority of patients. Spontaneous resolution was observed in nonsurgically managed cases. Accurate diagnosis by screening for USP6 rearrangement is essential to avoid overtreatment. This study underscores the benign nature of cNF and the importance of conservative management, especially in cosmetically sensitive areas.