Malignancy of the nail apparatus – clinical and dermoscopic analysis

Introduction
Malignant neoplasms of the nail apparatus are rare tumours, often diagnosed with delay, which influences the further course. Dermoscopy improves the clinical differentiation of benign and malignant conditions of the nail apparatus, patients’ follow-up and determination of the margins during surgical intervention (intraoperative onychoscopy). Herein we present another series of Polish patients with malignant tumours of the nail apparatus analysed with dermoscopy.

Objective
Epidemiological, clinical and dermoscopic analysis of patients with nail apparatus melanoma and nail apparatus squamous cell carcinoma.

Material and methods
We retrospectively analysed clinical data of 840 patients diagnosed and treated surgically at the Department of Dermatology, Venerology and Allergology, Medical University of Gdańsk (Poland) between January 2015 and November 2017. Three cases of nail apparatus melanoma and 4 cases of nail apparatus squamous cell carcinoma were identified and included in further detailed analysis. In all cases clinical diagnosis was confirmed histopathologically. Dermoscopy was available in 5 cases.

Results
Nail apparatus melanoma represented 8.3% of all diagnosed melanomas and nail apparatus squamous cell carcinoma 9.2% of all squamous cell carcinomas in the analysed period of time.

Conclusions
According to our material, nail apparatus malignancy is not uncommon. Dermoscopy supports the clinical differentiation between benign and malignant disorders of the nail apparatus, but should always be interpreted in association with medical history and physical examination. Histopathological examination remains the gold standard in the diagnosis of malignant tumours of the nail unit.