Intra-Operative Dermoscopy in Assessment of Melanonychia and as a Guide for Biopsy

Ishmeet Kaur; Sundeep Chowdhry; Paschal D'Souza; Deepak Jakhar; Mukesh Kumar Yadav; Onkar Kaur

doi:10.4103/idoj.IDOJ_94_19

Intra-Operative Dermoscopy in Assessment of Melanonychia and as a Guide for Biopsy

Indian Dermatol Online J. 2020 Mar 9;11(2):171-176. doi: 10.4103/idoj.IDOJ_94_19. eCollection 2020 Mar-Apr.

Authors

Ishmeet Kaur¹, Sundeep Chowdhry¹, Paschal D'Souza¹, Deepak Jakhar², Mukesh Kumar Yadav¹, Onkar Kaur³

Affiliations

¹ Department of Dermatology and Venereology and Leprosy, ESI-PGIMSR Hospital, Basaidarapur, Delhi, India.
² Department of Dermatology and Venereology and Leprosy, NDMC and Hindu Rao Hospital, Delhi, India.
³ Department of Pathology, ESI-PGIMSR Hospital, Basaidarapur, Delhi, India.

Abstract

Background and aims: Melanonychia can be a manifestation of benign or malignant pathology and often poses a diagnostic challenge on clinical examination. Even with distinguishing dermoscopic features (nail plate), it can be quite difficult to determine the nature of pigmentation as complete assessment of nail bed and matrix is still not possible. Intraoperative dermoscopy (IOD) can serve as a useful tool to appreciate the bed and matrix changes. The aim here is to study the intraoperative dermoscopic features in patients with melanonychia and correlate with histopathology.

Methods: 20 consecutive patients with melanonychia were recruited. Inclusion criteria was melanonychia of sudden onset, progressive nature, irregular width/color/symmetry on dermoscopy, positive Hutchinson sign, solitary nail involvement or associated nail dystrophy. Preoperative dermoscopy was performed and recorded. Patients were planned for nail matrix biopsy, during which IOD was performed over nail matrix and bed after removal of the nail plate. Images were recorded and analyzed and correlated with the histopathology.

Results: Out of 20 patients, 12 were females and 8 males. On IOD-histopathological correlation, 2 patients were found to have melanoma of the nail unit, 5had nail lichen planus, 9 had benign melanocytic nevi, and 4 had fungal melanonychia. IOD revealed fine, parallel and regular lines of pigmentation localized to proximal nail bed and matrix in all patients with benign melanonychia, while dark thick bands with irregular borders, dots, globules, streaks and structureless areas in the two patients with melanoma. Fungal melanonychia revealed an unremarkable nail bed and matrix on IOD.

Conclusion: Intraoperative dermoscopycan help in determining the nature of melanonychia and obviate the need to perform biopsy in certain cases. It can also aid in delineating the most suitable site for biopsy, along with grossly assessing the extent of involvement in case of malignancy.

Keywords: Dermatoscope; dermoscope; longitudinal pigmentary band; melanoma; melanonychia; nail; onychomycosis.