Dermoscopic features of 266 cases of melanonychia / 中华皮肤科杂志

Objective:To investigate dermoscopic manifestations and features of melanonychia.Methods:A retrospective analysis was carried out on dermoscopic images of 4 common types of melanonychia collected in Department of Dermatology, Xijing Hospital, the Fourth Military Medical University from January 2016 to July 2020.Results:A total of 266 cases of melanonychia were collected, including 64 (24.1%) of subungual melanoma, 52 (19.5%) of nail matrix nevi, 89 (33.5%) of subungual hemorrhage, and 61 (22.9%) of onychomycosis. Subungual melanoma and nail matrix nevi mostly occurred in the fingernails. To be specific, subungual melanoma most frequently occurred in the thumbnails (62.8%) , while nail matrix nevi mostly involved the 2 nd - 5 th fingernails (73.9%) . Subungual hemorrhage and onychomycosis mostly occurred in the toenails, and there were 51 (57.3%) cases of subungual hemorrhage of the toenails and 46 (75.4%) cases of onychomycosis of the toenails. Subungual melanoma mostly occurred in patients aged over 40 years (49 cases, 76.8%) , while the other 3 types of melanonychia mostly affected patients aged under 40 years. Dermoscopic manifestations of subungual melanoma mainly included regular longitudinal bands (35 cases, 54.7%) or irregular bands (25 cases, 39.0%) whose width was greater than 3 mm in 87.5% cases, Hutchinson sign (36 cases, 56.3%) , and ruptures (15 cases, 23.4%) which mainly were black-brown in color; dermoscopic manifestations of nail matrix nevi mainly were a single regular pigmented band (52 cases, 100%) whose width was less than 3 mm in 36 (69.2%) cases, and Hutchinson sign (26 cases, 50%) , while no ruptures were observed in nail matrix nevus lesions; subungual hemorrhage dermoscopically manifested as diffuse macules (74 cases, 83.1%) , and globular dark red or black hemorrhagic structures were observed in 85 (95.5%) cases; fungal melanonychia was dermoscopically characterized by irregular dark brown longitudinal bands (54 cases, 88.5%) . Conclusions:Subungual melanoma was dermoscopically characterized by regular longitudinal bands with a width of greater than 3 mm, nail matrix nevi by regular longitudinal bands, subungual hemorrhage by diffuse macules, and onychomycosis by irregular longitudinal bands. Dermatoscopy can be used to identify melanonychia lesions and provide a basis for auxiliary diagnosis of subungual melanoma.

Longitudinal Melanonychia in Korean Patients: A Clinical and Histopathologic Study of 75 Cases / 대한피부과학회지

BACKGROUND: Longitudinal melanonychia (LM) can be challenging as it may be caused by a wide variety of benign and malignant conditions. However, there are scarce data on LM confirmed by skin biopsy examination in Korean patients. OBJECTIVE: We sought to evaluate the clinical features and histopathologic diagnosis of LM in Korean patients. METHODS: We reviewed the medical records and clinical photographs of patients presenting with LM confirmed by skin biopsy examination between June 2007 and June 2017. RESULTS: Among a total of 75 patients with LM confirmed by skin biopsy examination at our hospital over a period of 10 years, 11 patients (14.7%) had malignant lesions. Common features of malignant lesions were involvement of a single nail, color heterogeneity, Hutchinson's sign, and nail plate dystrophy or ulceration. Common features of benign lesions were a negative Hutchinson's sign and absence of nail plate dystrophy and ulceration. CONCLUSION: This study analyzed the clinical features and histopathologic diagnosis of LM in Korean patients. Our data may contribute to determining the management approach for patients with LM.

Determination of clinical parameters for the differential diagnosis of malignant and benign longitudinal melanonychia / 中华皮肤科杂志

Objective To estimate the value of clinical parameters (such as patients' age,longitudinal melanonychia width and location) for the differential diagnosis of malignant and benign longitudinal melanonychia as well as for the evaluation of the necessity for invasive management.Methods A retrospective study was performed on 28 cases of subungual malignant melanoma collected from 2000 to 2010 as well as on 62 cases of benign longitudinal melanonychia from 2005 to 2010.Clinical analysis was carried out to compare the differences in clinical parameters such as.patients' age,longitudinal melanonychia width and lesional location,between the malignant melanoma and benign longitudinal melanonychia cases.Logistic regression analysis and ROC method were used to determine valuable clinical parameters for the differential diagnosis of malignant and benign longitudinal melanonychia.Results Significant differences were observed in the median age at diagnosis (23.0 years vs.52.5 years,Z =5.44,P ＜ 0.01 ),age at onset (21.0 years vs.48.0 years,Z =4.70,P ＜ 0.01 ),and longitudinal melanonychia width (3.0 mm vs.15.0 mm,Z =5.69,P ＜ 0.01 ) between the patients with malignant melanoma and benign longitudinal melanonychia.The involvement of thumb and hallux was observed in 77.8％ of the subungual melanoma cases,and 48.3％ of the benign cases (x2 =6.57,P ＜ 0.05).ROC method and Logistic regression analysis indicated that the age at onset and diagnosis as well as width of longitudinal melanonychia were of diagnostic value for the differential diagnosis of malignant and benign longitudinal melanonychia.Conclusions Not all longitudinal melanonychia cases need an invasive management at the time of awareness.The age at onset and diagnosis,width of melanonychia and site of the onset appear to be valuable in the differential diagnosis of malignant and benign longitudinal melanonychia,and there is a possibility to guide clinical diagnosis and treatment by establishing a mathematical model with these parameters.

A Case of Subungual Melanoma in Situ Presenting Longitudinal Melanonychia / 대한피부과학회지

A 43-year-old woman presented with two brown longitudinal streaks, which had been present in her left thumb for 5 years. A 3mm punch biopsy from the nail matrix showed that atypical melanocytes were scattered solitarily in suprabasal and basal layers. Five years after the first visit, she presented with changes of the longitudinal streaks. Two bands were altered into one 0.6cm-sized black pigmented band. There was dystrophy in the distal part of the thumb nail and extension of pigmentation to the skin adjacent to the nail plate, involving the nail fold. Axillary lymph-nodes were not palpable. A longitudinal incisional biopsy revealed increased large atypical melanocytes in suprabasal and basal layers of the epidermis. These findings strongly supported the diagnosis of subungual melanoma. Our case is interesting in that subungual melanoma presented longitudinal melanonychia.

Longitudinal Melanonychia due to Candida Species

A 55-year-old Korean female patient who presented with longitudinal black pigmentation affecting the right thumbnail is described. Direct microscopic examination of nail tissue in 15% potassium hydroxide and cultures on Sabourauds glucose agar revealed Candida species. Cardida species as a cause of longitudinal melanonychia has, to our knowledge, been described only once in the literature. Our case may be the second one.

A Case of Bowen' s Disease of the Nail Bed Presenting as Longitudinal Melanonychia / 대한피부과학회지

Bowens disease is an intraepithelial squamous cell carcinoma. It occur s anywhere on the surface of the body. Bowens disease involving the nail bed epithelium is very rate. Recently, some literatures showed that human papillomavirus is sssociated with squamous cell carcinoma of the finger by in situ hybridization or polymerase chain reaction. A 30-year-old housewife deve]oped longitudinal melanonychia with as imptomatic fissured nail plate on her right third finger. The hiat,ologic specimen showed diffuse anaplastic change confined to the nail bed epithelium. The subungual eyithelium was found to contain human papillomavirus DNA type 31/33/35 with the use of in situ hybridization.