New-onset cutaneous nodule arising from hypertrichotic brownish patch in a 6-year-old girl.

A 6-year-old girl presented with an enlarging asymptomatic nodule within a hyperpigmented hypertrichotic patch on her left thigh. Histopathological examination revealed tumour cells with round to fusiform nuclei in a fine fibrillary collagenous stroma, along with increased cellularity. Most of the tumour cells were positive for S-100 and negative for HMB-45 and Melan-A.