Longitudinal Melanonychia as a Presenting Sign of Onychopapilloma: A Case Report and Review of the Literature.

Longitudinal erythronychia: Suggestions for evaluation and management

Clinical, dermoscopic, and pathologic features of onychopapilloma: A review of 47 cases

Onychopapilloma: its clinical, dermoscopic and pathologic features.

Purpose: Tumorous conditions of the nail unit encompass a wide spectrum of benign and malignant lesions that present with diverse nail changes, many of which resemble one another. Early recognition of their characteristic clinical features is essential for accurate diagnosis and appropriate management. This review aims to summarize the clinical manifestations and therapeutic approaches of ten representative nail-associated tumors.Current Concepts: The discussed entities include benign tumors such as onychopapilloma, onychomatricoma, superficial acral fibromyxoma, periungual fibroma/fibrokeratoma, pyogenic granuloma, glomus tumor, digital myxoid cyst, and subungual exostosis, as well as malignant tumors such as squamous cell carcinoma and subungual melanoma. Each lesion demonstrates distinctive nail alterations: longitudinal erythronychia in onychopapilloma; a thickened, honeycombed nail plate in onychomatricoma; and a sharp-tipped periungual nodule in fibrokeratoma. Painful bluish discoloration suggests a glomus tumor, whereas ulcerated, rapidly growing vascular lesions favor pyogenic granuloma. Malignant tumors, including squamous cell carcinoma and melanoma, require heightened clinical suspicion when persistent onycholysis, nail dystrophy, or pigmentary changes with Hutchinson’s sign are observed.Discussion and Conclusion: Accurate diagnosis of nail tumors relies on careful correlation of clinical findings, dermoscopy, and histopathology. Surgical excision remains the primary treatment option for most benign and malignant nail tumors, while minimally invasive and laser-based approaches are emerging for select lesions. Understanding the diverse spectrum of nail changes in tumorous conditions enhances diagnostic precision, reduces unnecessary procedures, and facilitates timely management of potentially life-threatening malignancies.

Subungual acantholytic dyskeratotic acanthoma: an unusual cause of longitudinal erythronychia

Longitudinal melanonychia in children: A clinical and histopathologic study of 40 cases

Nail deformities often result from subungual masses, necessitating histopathological confirmation after surgical removal. While glomus tumors exhibit distinct clinical features, certain conditions, such as ganglion cysts, can mimic them and cause similar deformities. A 55-year-old male with a history of nail root trauma presented with nail deformity and tenderness in his left middle finger. Imaging identified a well-defined, hypoechoic lesion measuring 0.84 cm × 0.58 cm, which was surgically excised and confirmed as a ganglion cyst. Given the diverse nature of subungual masses–ranging from benign to malignant–histopathological analysis is crucial for accurate diagnosis. Subungual ganglion cysts (SGCs) are rare and difficult to detect; clinical evaluation plays a key role in distinguishing them. To prevent recurrence and misdiagnosis as glomus tumors, surgeons should carefully consider SGCs and employ precise surgical techniques.

The article aims to be a guide to the interpretation of tumors specific to the nail, that is, tumors presenting peculiar histological features linked specifically to the nail unit. Therefore, the classical epithelial, fibroepithelial, and fibrous skin tumors occurring in the nail region are not analyzed. The interpretation of nail biopsies requires the identification and integration of the 2 main clinical modes of presentation of nail tumors, the acquired localized (monodactylous) longitudinal (ALL) band pattern, and the "masked" nail tumor. The ALL band pattern often allows the recognition of a nail tumor in its early phase of progression, with a limited differential diagnosis. The masked nail tumor mimics an inflammatory nail process, as a clinically misleading reactive benign lesion, which delays diagnosis with the subsequent development of partial nail loss and a locally destructive evolution. ALL band pattern appears as a longitudinal band starting at the matrix and extending to the tip of the nail plate. The band is usually single, rarely bifid. This clinical pattern can divided into 2 presentations. The generic term of ALL maculonychia could be proposed to define the macular aspect of the colored band of the nail plate. It encompasses 3 syndromes: longitudinal melanonychia, longitudinal erythronychia, and longitudinal leukonychia. ALL pachyonychia is a rare presentation. Pachyonychia indicates a localized thickening of the nail plate specific to the matrical nail tumor. In this group, there is differentiation toward cells of the nail matrix. The prototype tumor is the onychomatricoma, which present classically with a yellow (xantholeukonychia) band pattern. Recently, a new clinical band pattern has been described as longitudinal pachymelanonychia with 2 etiologies: pigmented onychomatricoma and onychocytic matricoma. The first part of this review delineate, in the first section, the distinctive microanatomical features of the nail unit and the second is dedicated to the most important pitfalls in pathological diagnosis of nail tumors because of nail surgery techniques. In the third section, the histopathology of ALL melanonychia and ALL erythronychia is discussed in a detailed description.

Longitudinal erythronychia is a linear red band on the nail plate that originates at the proximal nail fold, traverses the lunula, and extends to the free edge of the nail plate. Longitudinal erythronychia is classified based upon the number of nails affected and the number of red streaks present on each nail as follows: type Ia (monodactylous - single band), type Ib (monodactylous - bifid bands), type IIa (polydactylous - single band), and type IIb (polydactylous - multiple bands). Associated morphologic findings that can be present at the distal tip of the nail with longitudinal erythronychia include fragility, onycholysis, splinter hemorrhage, splitting, subungual keratosis, thinning, and V-shaped nick. Some patients with longitudinal erythronychia seek medical evaluation because of pain in the associated distal digit; however, the linear red nail plate dyschromia is often asymptomatic and the individual is concerned about the cosmetic appearance or distal nail fragility. Longitudinal erythronychia can be a clinical manifestation of an underlying local or systemic condition. Benign tumors (glomus tumor, onychopapilloma, and warty dyskeratoma), malignant neoplasms (malignant melanoma and squamous cell carcinoma), and other conditions (hemiplegia and postsurgical scar) can be associated with monodactylous longitudinal erythronychia or it may be idiopathic or the initial stage of polydactylous longitudinal erythronychia-associated systemic conditions. Polydactylous longitudinal erythronychia is most commonly reported in patients with Darier disease (keratosis follicularis); other associated conditions include acantholytic dyskeratotic epidermal nevus, acantholytic epidermolysis bullosa, acrokeratosis verruciformis of Hopf, amyloidosis, graft-versus-host disease, lichen planus, and pseudobulbar syndrome. Polydactylous longitudinal erythronychia has also been observed as an idiopathic finding. Biopsy of the nail matrix and nail bed may be necessary to establish the diagnosis of a longitudinal erythronychia-associated condition. Indeed, a biopsy should be seriously considered in patients aged more than 50 years who present with a monodactylous longitudinal red band to exclude squamous cell carcinoma. Treatment of longitudinal erythronychia depends on the etiology. For patients with longitudinal erythronychia-associated discomfort or severe nail splitting, a surgical excision may provide not only the underlying diagnosis of the nail dyschromia, but also relief of related symptoms.

Onychopapilloma is a benign tumor of the distal nail matrix and proximal nail bed with heterogeneous clinical presentations. It poses a diagnostic challenge because it could mimic subungual malignancies and inflammatory conditions. Clinical, onychoscopic, and histopathological clues play critical roles in diagnosis. We performed a retrospective chart review of onychopapilloma cases collected over 10 years, and characterized the clinical, onychoscopic, and histopathological features of onychopapilloma at an academic institution. We obtained 17 biopsy-confirmed cases of onychopapilloma. Among our cases, we found manifestation of onychopapilloma as longitudinal erythronychia, longitudinal leukonychia, yellow-brown chromonychia, and longitudinal melanonychia. Long longitudinal or short splinter hemorrhages may be present. Distal fissuring with V-shaped notch, subungual keratotic mass, and onycholysis are other discernable features. Histopathological features include papillomatosis, epidermal hyperplasia, acanthosis of the distal nail bed, premature keratinization, matrix metaplasia, hyperkeratosis, and splinter hemorrhages; histopathological signs of malignancy were not observed in any of our cases. Onychopapilloma has polymorphic clinical and morphological features. Onychoscopic and histopathological studies are important to help exclude malignant mimickers. Consider onychopapilloma in the differential diagnoses of a monodactylous longitudinal streak in the nail, especially on the left thumb of an adult female.

Longitudinal erythronychia (LE) is a term for red streaks in the nail. We describe the range of diseases manifested by localized (single or bifid) LE and explain the underlying physical changes. Longitudinal erythronychia can be multiple or localized. Multiple lesions typically indicate an inflammatory disease such as lichen planus. When localized, they may be a single or bifid streak arising through a benign or malignant neoplasm, scarring of the dermis or epidermis, or the first stage of an inflammatory process that may evolve into multiple LE. Excision of a localized LE may provide a diagnosis and cure. Incisional matrix biopsy of multiple LE may provide a diagnosis. Clinical manifestation of LE arises through reduced compression of the nail bed due to loss of bulk of the nail plate with a groove on the undersurface. A streak of thinned nail then allows an enhanced view of a corresponding streak of engorged nail bed. The reduction in nail thickness renders it more fragile with a tendency to split distally. Understanding LE can assist in diagnosis and explanation to the patient. Localized LE may represent a focal tumor or dysplastic process.

Nail lines are a common presenting finding. A thorough inspection of the fingernails and toenails is an integral part of the complete physical examination. An understanding of basic nail anatomy and familiarity with several basic types of nail line enable the clinician to diagnose and treat nail disorders and to recognize underlying systemic diseases, as each type of nail line has a particular differential diagnosis. The authors review leukonychia striata (white lines), longitudinal melanonychia (brown-black lines), longitudinal erythronychia (red lines), and nail-plate grooves (Beau lines).

- Virtual dataset E - Web dataset (3317 images) - Diagnosis predicted by CNNs (ResNet-152 + VGG-19; arithmatic mean of both outputs; training dataset: A1) We created the E dataset to assess the semisupervised learning performance by conducting a Web-based image search for “tinea,” “onychomycosis,” “nail dystrophy,” “onycholysis,” and “melanonychia” in English, Korean, and Japanese on http://google.com and http://bing.com, and downloaded a total of 15,844 images. From these images, the R-CNNs created a nail dataset of 3,317 images, since we had to discard many images because of low image resolution. The CNNs (model: ResNet-152 + VGG-19; arithmetic mean of both outputs; training dataset: A1) automatically classified images generated by the R-CNNs into six classes (760 onychomycosis, 1,316 nail dystrophy, 363 onycholysis, 185 melanonychia, 424 normal, and 269 others).

Clinical features and natural course of pediatric longitudinal melanonychia: A retrospective cohort study in Korea

Melanoma and squamous cell carcinoma on different nails of the same hand