Melanocytic Lesions of the Nail Unit (original) (raw)
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Pigmented lesions of the nail unit
Seminars in cutaneous medicine and surgery, 2015
Longitudinal melanonychia originates from pigmented and/or melanocytic lesions of the nail unit. It may be a less-common entity encountered in dermatologic practice, but it is often a vexing one. Lesions occurring at this location present particular problems due to the unfamiliarity with clinical assessment, their relative inaccessibility, requiring more surgical finesse, and the lack of experience with histopathologic examination. Obtaining a specimen sufficient for interpretation is one of the main impediments to successful diagnosis in this setting. Most pigmented bands are benign, due to more common entities such as melanocytic activation, lentigo, and/or a nevus; however, deciding which ones are due to melanoma is of the utmost importance and can be difficult. Some examples of melanoma at this site are amelanotic, which are more challenging to recognize clinically, and usually lead to significant delays in diagnosis. In order to provide optimal patient care in this setting, it ...
Dermatologic surgery : official publication for American Society for Dermatologic Surgery [et al.], 2015
Background: Nail unit melanoma (NUM) is a rare variant of acral lentiginous melanoma. The differential diagnosis is wide but an acquired brown streak in the nail of a fairskinned person must be considered a potential melanoma. Dermatoscopy helps clinicians to more accurately decide if a nail apparatus biopsy is necessary. Methods: We report the case of a 61-year-old Caucasian woman with melanonychia occupying the central portion of the right thumbnail plate with 1 year of evolution. Dermatoscopy showed a brown pigmentation overlaid by longitudinal irregular lines. An excisional biopsy was performed, and pathological examination revealed melanoma in situ. For safety reasons, the nail unit was totally removed down to the phalangeal bone 3 weeks later, and a full-thickness skin graft taken from the arm was used for reconstruction. Conclusion: NUMs pose a difficult treatment challenge. Wide excision with phalanx amputation is not satisfactory for patients with in situ and early invasive melanoma. Full-thickness skin grafting after total nail unit excision is a simple procedure providing a good functional and cosmetic outcome.
Adult and Pediatric Nail Unit Melanoma: Epidemiology, Diagnosis, and Treatment
Cells
Nail unit melanoma (NUM) is an uncommon form of melanoma and is often diagnosed at later stages. Approximately two-thirds of NUMs are present clinically as longitudinal melanonychia, but longitudinal melanonychia has a broad differential diagnosis. Clinical examination and dermoscopy are valuable for identifying nail findings concerning malignancy, but a biopsy with histopathology is necessary to confirm a diagnosis of NUM. Surgical treatment options for NUM include en bloc excision, digit amputation, and Mohs micrographic surgery. Newer treatments for advanced NUM include targeted and immune systemic therapies. NUM in pediatric patients is extremely rare and diagnosis is challenging since both qualitative and quantitative parameters have only been studied in adults. There is currently no consensus on management in children; for less concerning melanonychia, some physicians recommend close follow-up. However, some dermatologists argue that the “wait and see” approach can cause delay...
Dermatologists' Accuracy in Early Diagnosis of Melanoma of the Nail Matrix
Archives of Dermatology, 2010
To measure and compare the accuracy of 4 different clinical methods in the diagnosis of melanoma in situ of the nail matrix among dermatologists with different levels of clinical experience. Design: Twelve cases of melanonychias (5 melanomas and 7 nonmelanomas) were presented following 4 successive steps: (1) clinical evaluation, (2) evaluation according to the ABCDEF rule, (3) dermoscopy of the nail plate, and (4) intraoperative dermoscopy. At each step, the dermatologists were asked to decide if the lesion was a melanoma.
Important malignant and new nail tumors
The nail apparatus is an integral part of the functional unit of the digital tip. Although overall uncommon, all cells and tissues occurring in this area can give rise to neo-plastic lesions. Given the special anatomical location, such tumors frequently show morphological and symptom-related differences compared to similar lesions located elsewhere on the skin. Though particularly threatening, there is often a substantial delay in the diagnosis of Bowen's disease, ungual squamous cell carcinoma, and melanoma. Nevertheless, local excision with sufficient surgical margins is usually sufficient and superior to amputation of the distal phalanx. In recent years, a number of nail-specific tumors have been described. Tumors such as onychomatricoma, ony-chocytic matricoma, onychocytic carcinoma, and onychopapilloma originate from the nail matrix. Onycholemmal cysts, onycholemmal horn, and the proliferating onycholemmal tumor are characteristic nail bed tumors. Onycholemmal carcinoma is a slowly growing low-grade malignancy. Using modern diagnostic methods, careful examination – including biopsy and histopathology – of nail changes not responding to conservative treatment will help identify nail-specific neoplasms and prevent the progression of malignant nail tumors.
Dermatology practical & conceptual, 2017
We present a case of nail apparatus melanoma in a 50-year-old woman presenting as new and changing longitudinal melanonychia of the right thumb. Very heavy melanin pigmentation involving both the epidermis and dermis interfered with dermatopathological assessment, which initially leads to a diagnosis of nail matrix blue nevus. After consultation with a specialist multidisciplinary clinic the diagnosis was revised to invasive melanoma, a diagnosis consistent with the clinical and dermatoscopic assessment.