Desmoplastic melanoma on the nose: electrochemotherapy as an alternative treatment to local advanced disease

Background: Desmoplastic malignant melanoma (DMM) is a rare and usually misdiagnosed type of melanoma. Delayed detection at complicated anatomical locations can lead to the necessity of alternative therapies.

Objective: Characterization of DMM on the nose, which is the second more frequent type of MM.

Methods: Review of case series of eight pathologically proven DMM on the nose from two referral centres with a mean follow-up of 69 ± 40.5 months.

Results: According to a single centre experience, there is a more than 70-fold increased risk of having a DMM on the nose compared with a non-DMM (P < 0.0005, CI99% 16.3-317.3). Clinical and pathological misdiagnoses were frequent, only three of the eight cases were properly diagnosed and treated and indeed they did not experience relapses. Due to non-clinical suspicion and superficial biopsies, three cases were initially pathologically misdiagnosed as basal cell carcinomas and a nevus respectively. Atypical vessels and remnants of pigment on dermoscopy are indicative findings even in non-pigmented cases. Although not significant, the mean disease-free survival differed between cases with a correct initial management (four cases, 66.7 ± 57.3 months) in contrast to improper (four cases, 16.25 ± 18.9 months). Electrochemotherapy achieved a complete local control of disease in two cases unsuitable for surgery.

Conclusions: Use of dermoscopy and correctly selected biopsy of lesions on the face is mandatory to improve early diagnosis of DMM. Improper management of challenging cases implies a more complicated therapy and loco-regional invasion risk. Electrochemotherapy could be a promising therapy in local advanced tumours.