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.

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.

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