Copyright ©The Author(s) 2018. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Clin Cases. Sep 26, 2018; 6(10): 322-334
Published online Sep 26, 2018. doi: 10.12998/wjcc.v6.i10.322
Mystery behind labial and oral melanotic macules: Clinical, dermoscopic and pathological aspects of Laugier-Hunziker syndrome
Ning Duan, Yang-Heng Zhang, Wen-Mei Wang, Xiang Wang
Ning Duan, Wen-Mei Wang, Xiang Wang, Department of Oral Medicine, Nanjing Stomatological Hospital, Medical School of Nanjing University, Nanjing 210008, Jiangsu Province, China
Yang-Heng Zhang, Department of Periodontology, Nanjing Stomatological Hospital, Medical School of Nanjing University, Nanjing 210008, Jiangsu Province, China
Author contributions: Duan N, Zhang YH and Wang WM contributed to this paper equally, and should be considered as co-first author; all the authors read and approved the final version of the manuscript before submission.
Supported by The National Natural Scientific Foundation of China, No. 81570978; the Nonprofit Industry Research Specific Fund of National Health and Family Planning Commission of China, No. 201502018; the Key Project of Science and Technology Department of Jiangsu Province, No. BL2014018; and the Project of Invigorating Health Care through Science, Technology and Education: the Project of Jiangsu Provincial Medical Youth Talent, No. QNRC2016118.
Conflict-of-interest statement: All the authors declare no conflicts of interest.
Open-Access: This article is an open-access article, which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See:
Correspondence to: Xiang Wang, MD, PhD, Associate Specialist, Department of Oral Medicine, Nanjing Stomatological Hospital, Medical School of Nanjing University, 30 Zhongyang Road, Nanjing 210008, Jiangsu Province, China.
Telephone: +86-25-83620220 Fax: +86-25-83620202
Received: April 21, 2018
Peer-review started: April 21, 2018
First decision: June 15, 2018
Revised: June 28, 2018
Accepted: July 23, 2018
Article in press: July 24, 2018
Published online: September 26, 2018

Labial and oral melanotic macules are commonly encountered in a broad range of conditions ranging from physiologic pigmentation to a sign of an underlying life-threatening disease. Although Laugier-Hunziker syndrome (LHS) shares some features of labial and oral pigmentation with a variety of conditions, it is a benign and acquired condition, frequently associated with longitudinal melanonychia. Herein, the demographic, clinical, dermoscopic, and pathological aspects of LHS were reviewed comprehensively. The important differential diagnoses of mucocutaneous and nail pigmentation are provided. An accurate diagnosis is crucial to design a reasonable medical strategy, including management options, malignant transformation surveillance, and psychological support. It is important that clinicians conduct long-term follow-up and surveillance due to the potential risks of malignant transformation and local severe complications in some conditions.

Keywords: Laugier-Hunziker syndrome, Dermoscopy, Pathology, Pigmentation, Differential diagnosis, Peutz-Jeghers syndrome, Neurofibromatosis type 1, Carney complex, Melanonychia

Core tip: Although Laugier-Hunziker syndrome (LHS) is an uncommon disorder, labial or oral pigmentation is often encountered daily and clinically. By conducting a thorough review of the topic, the aims of the paper are to present the clinical, dermoscopic, and pathological features of LHS concisely and clearly. More to the point, the outlined typical features of various conditions associated with labial, oral, and nail pigmentation are conducive to facilitate differential diagnosis, promote early recognition of underlying diseases, and prevent unnecessary testing.