# Highlighting a histopathological dilemma: atypical dermatofibrosarcoma protuberans diagnosed with multimodal dermoscopy

## TL;DR

A case study shows how combining different types of dermoscopy with histopathology and immunohistochemistry helps diagnose a rare skin tumor.

## Contribution

Demonstrates the diagnostic value of integrating multimodal dermoscopy with histopathology and IHC for atypical dermatofibrosarcoma protuberans.

## Key findings

- Multimodal dermoscopy revealed key features of a myxoid variant of DFSP.
- Histopathology showed spindle-cell infiltrate without atypia.
- Immunohistochemistry confirmed CD34 positivity and S100 negativity.

## Abstract

An adult male agricultural worker presented with an asymptomatic, heterogeneously pigmented, indurated nodule featuring multiple protuberances on the left pelvic skin. Cross-polarized dermoscopy revealed pink structureless areas and a hyperpigmented reticular network; yellow light dermoscopy accentuated the pigmentary network and entangling vasculature. Ultraviolet-induced fluorescence dermoscopy demonstrated blue–white autofluorescence of surface keratin and milky-white fluorescence of the collagenous/myxoid stroma. Histopathology showed a monomorphic spindle-cell infiltrate without atypia; immunohistochemistry (IHC) confirmed a CD34-positive, S100-negative spindle-cell neoplasm consistent with a myxoid variant of dermatofibrosarcoma protuberans. This case highlights the diagnostic utility of multimodal dermoscopy integrated with histopathology and supportive IHC in precisely evaluating atypical cutaneous tumours.

An adult with a protuberant cutaneous nodule underwent multimodal dermoscopy, revealing features suggestive of dermatofibrosarcoma protuberans (DFSP). Despite inconclusive histopathology, immunohistochemistry confirmed a myxoid variant of DFSP. This case highlights the critical integration of multimodal dermoscopy, histology and advanced diagnostics to resolve challenging cutaneous tumours.