Diagnosis of dermatofibrosarcoma protuberans and assessment of pre-surgical margins using high-definition optical coherence tomography imaging

Dermatofibrosarcoma protuberans (DFSP) is a slow‐growing, fibrohistiocytic tumour that corresponds to 0.1–1% of all skin malignant neoplasms. Its indolent course and lack of early clinical clues account for frequent delays in diagnosis.1 Recognition of six recently described dermoscopic features could raise the suspicion for DFSP, avoiding diagnostic pitfalls and improving patient outcome.2 DFSP has a high recurrence rate after incomplete surgical excision. Therefore, a 2–4 cm wide local excision (WLE) or Mohs micrographic surgery is considered the treatment of choice.3 Imaging studies can provide additional information concerning disease extent. Magnetic resonance imaging and Doppler ultrasonography have been used with variable results.4, 5 Several non‐invasive imaging techniques, including high‐definition optical coherence tomography (HD‐OCT), have emerged in recent years aiming for higher accuracy of in vivo diagnosis. HD‐OCT is capable of capturing not only slice but also en face images in real‐time and fast three‐dimensional acquisition, enabling visualization of individual cells.6 Hence, it represents an ideal tool for diagnostic purposes in skin cancer, and also for monitoring surgical and non‐surgical treatment