Acrokeratosis paraneoplastica (Basex syndrome) with trachyonychia preceding the diagnosis of squamous cell carcinoma of the lung.

Acrokeratosis paraneoplastica (Basex syndrome) is a rare paraneoplastic condition hallmarked by psoriasiform lesion development on acral surfaces, most often related to an underlying squamous cell carcinoma. Patients may also present with nail plate changes. Successful management of this condition can be accomplished by treating the underlying malignancy.

Coxsackievirus A10 impairs nail regeneration and induces onychomadesis by mimicking DKK1 to attenuate Wnt signaling.

Coxsackievirus A10 (CV-A10) infection, a prominent cause of childhood hand-foot-and-mouth disease (HFMD), frequently manifests with the intriguing phenomenon of onychomadesis, characterized by nail shedding. However, the underlying mechanism is elusive. Here, we found that CV-A10 infection in mice could suppress Wnt/ß-catenin signaling by restraining LDL receptor-related protein 6 (LRP6) phosphorylation and ß-catenin accumulation and lead to onychomadesis. Mechanistically, CV-A10 mimics Dickkopf-related protein 1 (DKK1) to interact with Kringle-containing transmembrane protein 1 (KRM1), the CV-A10 cellular receptor. We further found that Wnt agonist (GSK3ß inhibitor) CHIR99021 can restore nail stem cell differentiation and protect against nail shedding. These findings provide novel insights into the pathogenesis of CV-A10 and related viruses in onychomadesis and guide prognosis assessment and clinical treatment of the disease.

Managing longitudinal melanonychia.

Longitudinal melanonychia (LM) is a pigmented band extending from the matrix to the distal edge of a nail. It is caused by increased production of melanin within the matrix, and integration into the nail plate. The origin of this production is usually benign, due to activation, hyperplasia or proliferation of melanocytes normally present in the matrix. In some cases, however, LM is the manifestation of a subungual melanoma, the diagnosis of which must be made early. Biographical, clinical and dermoscopic criteria make it possible to suspect melanoma and decide whether to perform biopsy. None of these criteria, however, are specific and definitive diagnosis requires pathologic examination of a matrix biopsy. The biopsy technique should enable reliable histological study while limiting the risk of secondary nail dystrophy. Initial resection should ideally involve the entire lesion. Complete elevation of the nail plate enables the lesion to be precisely located. Lesions up to 3 mm can be removed by longitudinal resection biopsies without significant sequelae. In more extensive lesions, incision or tangential ("shave") biopsy can be performed without impairing prognosis. In clinical presentations strongly suggestive of melanoma, immediate complete resection of the entire nail unit may be proposed.

[Cutaneous adverse events to systemic anticancer therapies : Hand-foot syndrome and nail changes]. / Kutane Nebenwirkungen onkologischer Systemtherapien : Hand-Fuß-Syndrom und Nagelveränderungen.

BACKGROUND: Hand-foot syndrome (HFS) and nail changes are frequent adverse events of anticancer therapies. OBJECTIVES: To provide a review of current evidence in HFS and nail disorders associated with medical tumor treatment. MATERIALS AND METHODS: Basis is the current German S3 guideline "Supportive therapy in oncologic patients" and literature on this topic published since the guideline was finalized. RESULTS: Two variants of HFS are distinguished: a chemotherapy-associated and a kinase-inhibitor-associated variant. In the first form, painful erythema, blisters and ulceration can occur, also in other areas with a high number of sweat glands such as axillary and inguinal regions. Thus, the secretion of toxic substances through sweat glands is a proposed pathogenetic mechanism. For the second form, which results in callus-like painful thickening of the horny layer on areas of mechanic pressure, a vascular mechanism is proposed. For prophylaxis of HFS, avoidance of mechanical stress, regular cleaning of predisposed areas, and also urea- and diclofenac-containing ointments are recommended; in case of infusions (taxanes, doxorubicine), cooling of hands and feet during infusion is recommended. In case of manifest HFS, dose reduction or prolongation of intervals of the associated treatment are recommended. Nail changes often develop under therapy with chemotherapeutic agents but also under treatment with agents such as checkpoint inhibitors or under targeted therapy. Different components of the nail unit may be involved such as the nail matrix, nail bed, nail plate, hyponychium, lunula and proximal and lateral nail folds. CONCLUSION: This work gives insight into the pathophysiology of HFS and nail disorders that develop under systemic oncologic treatments and gives recommendations for prophylaxis and treatment.

Retronychia: the importance of proper footwear.

Retronychia is commonly underdiagnosed and exhibits classic features of proximal nail fold elevation and nail plate layering. Herein we summarize the literature and discuss cause, diagnosis, and treatment of this condition.

Subungual Osteochondroma of the Great Toe: A Case Report.

Bony outgrowths of the distal phalanx of the great toe have been described in the literature but rarely. These subungual bony outgrowths can be caused by subungual exostosis or subungual osteochondromas. Both of these abnormalities are bony outgrowths with differences in the cartilage cap wherein the exostoses have fibrocartilage, and osteochondromas have hyaline cartilage. The subungual exostosis and osteochondroma that are protruding present symptoms of pain, redness, and deformed nail bed, whereas the nonprotruding osteochondromas have only a lump as the presenting symptom. In both conditions, excision of the lesion and curettage of the base helps prevent a recurrence. Curettage at the end of the excision of the bony outgrowth is required to avoid recurrence. After excision, the specimen should be sent for histopathologic examination to differentiate between the exostosis and osteochondromas, which are underreported in subungual locations, and to rule out malignant transformation. We present a 13-year-old girl with an isolated subungual nonprotruding exostosis of the great toe that was treated by excisional biopsy. The histopathologic examination confirmed it as osteochondroma, which is underreported.

Outcomes of the Transungual Approach in 56 Consecutive Digital Subungual Glomus Tumours.

Background: Glomus tumour is a painful small tumour of the glomus body commonly located under the nail bed. The aim of this study is to evaluate the correlation of clinical diagnosis with MRI findings, determine the prevalence of the tumour at different subungual locations and determine the differences in outcomes (if any) between a longitudinal and a transverse nail bed incision for excision of the tumour. Methods: This retrospective study of 56 subungual glomus tumour was conducted from May 2010 to December 2021. Data with regard to gender, age at presentation, digit involved, presenting symptoms, duration of symptoms, clinical signs, need for MRI, anatomical location, surgical approach (longitudinal versus transverse), histopathology result, period of follow-up and complications were recorded. Results: All 56 (100%) patients presented with classic triad of symptoms. The average duration of symptoms was 52.9 months (range: 3-204 months). Eleven (20%) tumours were in the sterile matrix, 38 (68%) at the junction of sterile and germinal matrix and 7 (12%) in the germinal matrix. The tumours were excised through the longitudinal incision in 31 (55.3%) patients and transverse incision in 25 (44.7%). One (1.8%) tumour was intraosseous that was diagnosed intraoperatively and excised successfully. Average follow-up was 35.4 months (range: 6-120 months). There was no difference in outcomes (pain or nail deformity) between the two incisions. One patient (1.8%) has persistent pain that was due to a missed satellite lesion in the same digit. This was excised later with resolution of symptoms. There were no recurrences and all patients were cured after excision of tumour. Conclusions: Diagnosis of glomus tumour is usually clinical, and most are located at junction of sterile and germinal matrix. Tumour can be excised either by longitudinal or transverse nail bed incisions without any change of treatment outcome. Level of Evidence: Level IV (Therapeutic).

Subungual melanoma with cartilaginous differentiation: Molecular insights.

Melanoma's rare capacity to undergo heterologous differentiation can create significant diagnostic challenges. The molecular mechanisms underlying this phenomenon are not well understood. We present an unusual case of subungual melanoma exhibiting extensive cartilaginous differentiation and provide insights into its molecular and cytogenomic features. Histopathologically, the tumor was predominantly composed of nodules of malignant cartilage in association with a smaller population of nested epithelioid to rhabdoid cells. Immunohistochemically, the tumor cells in both components were positive for S100, SOX10, and PRAME, and were negative for Melan-A and HMB-45. Molecular analysis by whole exome DNA sequence did not detect any pathogenic variants in genes commonly implicated in melanoma. Additional analysis by SNP chromosomal microarray revealed a complex genome characterized by numerous chromosomal losses and gains, including a homozygous deletion of the CDKN2A locus and a heterozygous deletion of the locus containing EXT2, a tumor suppressor implicated in hereditary multiple osteochondromas and secondary chondrosarcomas. This case underscores the importance of recognizing cartilaginous differentiation as a rare manifestation of melanoma, particularly at subungual sites, and suggests that at least some of these melanomas may be driven by non-canonical molecular pathways.

Clinical, onychoscopic, nail clipping, and histopathological findings of malignant onychopapilloma.

This report describes the clinical, onychoscopic, nail clipping, and histopathologic features of a malignant onychopapilloma. A 71-year-old male presented to our outpatient clinic for a stable, asymptomatic lesion on his left middle finger that had been present for 2 years. Prior nail clipping histopathology showed nail plate thinning with subungual abnormal onychocytes. Clinical examination revealed a 2-mm-wide streak of longitudinal xanthonychia extending to the proximal nail fold, with distal hyperkeratosis and onycholysis. Onychoscopy showed irregular longitudinal nail plate ridging with scattered punctate hemorrhagic foci. An excisional nail unit biopsy demonstrated cellular atypia of the nail bed epithelium, matrix metaplasia, longitudinal abnormal onychocytes, increased Ki-67 staining, and negative HPV immunoperoxidase staining, confirming the diagnosis of malignant onychopapilloma.

Apocrine Hidrocystoma of the Nail: A Unique Case.

ABSTRACT: Apocrine hidrocystomas are benign, cystic neoplastic lesions resulting from the apocrine secretory component of the sweat gland. They most commonly occur on the head and neck, with predilection to the periorbital area. Less frequent sites include the axilla, nipple, external auditory canal, foreskin, conjunctiva, lower lip, and fingers, among others. The authors report a unique case of a nail bed hidrocystoma in a 55-year-old woman, a site not previously described.

Nails as Dynamic, Not Static, Entities-Rethinking the Approach to Nail Disorders.

This Viewpoint discusses the need for a broader approach to nail pathology, in which infectious, inflammatory, systemic, and structural factors are considered.

Nail involvement in connective tissue diseases: an epidemiological, clinical, and dermoscopic study.

BACKGROUND: The assessment of nail changes in connective tissue diseases (CTD) has been rarely explored in previous studies. The use of dermoscopy to study vascular changes in nailfolds is an interesting diagnostic technique. The aim of the study was to describe the epidemiological, clinical, and dermoscopic features of nail lesions in CTD. METHODS: A prospective study was performed at the Dermatology Department of Habib Thameur Hospital (Tunis, Tunisia) in collaboration with the Internal Medicine Department over a period of 15 months, from July 2020 to September 2021, including patients diagnosed with systemic sclerosis (SS), systemic lupus erythematosus (SLE) and dermatomyositis (DM). RESULTS: Our study included 48 patients. Nail involvement was found in 44 cases. Dermoscopic nailfold abnormalities were identified in 37 cases. The most common clinical features were ragged cuticle, nailfold erythema, and onycholysis. Additionally, splinter hemorrhage, longitudinal ridging, lunula abnormalities, melanonychia, trachyonychia, leukonychia, increase in transverse curvature, parrot beak nail, half and half nails, and onychorrhexis were described. Nailfold dermoscopy showed a normal pattern in 10 cases, a nonspecific pattern in nine cases (SLE), and a scleroderma pattern in 29 cases (SS and DM). The scleroderma pattern was further categorized into an early pattern (6), an active pattern (14), and a late pattern (9). Normal pattern was observed solely in patients in remission. The late scleroderma pattern was associated with disease duration and systemic involvement. In SLE, disease activity correlated with onycholysis, nailfold erythema, and pathologic pattern in dermoscopy. However, patients with DM displayed a positive correlation between pulmonary involvement and scleroderma pattern. CONCLUSION: Nail involvement in CTD includes a diverse range of abnormalities. Despite being nonspecific, it can provide crucial clues for establishing a diagnosis. Nailfold dermoscopy serves as a mirror for microangiopathy, enabling the detection of changes at an initial stage, and thus, it becomes a diagnostic and prognostic tool.

Onychocytic Matricoma: A Clinical, Dermoscopic, and Pathological Analysis of 14 Cases.

ABSTRACT: Onychocytic matricoma (OCM) is a benign neoplasm of the nail matrix. Only 18 cases of this tumor have been reported in the literature to date. We retrospectively analyzed the clinical features of 14 patients with OCM. The most common clinical feature was longitudinal xanthopachyonychia (n = 9), followed by longitudinal leukopachyonychia (=3) and longitudinal pachymelanonychia (n = 2). The most common clinical findings identified following dermoscopy and analysis at high magnification of classical photographs were free-edge thickening of the nail plate without pitting (n = 14), longitudinal ridging (n = 7), round white clods (n = 7), white dots (n = 7), and filiform hemorrhages (n = 7), followed by oval and linear white clods (n = 5), fuzzy lateral border (n = 5), and red-purple blood clods (n = 3). Nail clipping histopathology showed a thickened nail plate with multiple, small, round-to-oval spaces. The tumor expressed immunopositivity for LEF-1. Dermoscopy of the nail plate and nail clipping histology provides useful information with regards to the differential diagnosis with subungual squamous cell carcinoma and nail melanoma. Ex vivo-in vivo correlation facilitates a better dermoscopic assessment of this unique underrecognized disease. However, the differential diagnosis between OCM and onychocytic carcinoma requires biopsy of the tumor. LEF-1 as an onychogenic marker can be used to resolve the differential diagnosis between OCM and subungual longitudinal acanthoma/seborrheic keratosis.

Umbilical psoriasis is not relevant to psoriatic arthritis.

Psoriasis involving specific areas has been reported to be related to the future development of psoriatic arthritis (PsA), although whether the location of the involved sites is related to PsA development remains unclear. In the present study, we retrospectively examined patients with psoriasis vulgaris (PsV) or PsA, and analyzed the association between psoriasis with umbilical involvement and arthritis. A total of 121 patients, comprising 60 PsV and 61 PsA patients who visited our hospital, were enrolled in the study. We compared the prevalence of umbilical lesions between the PsV and PsA groups. In addition, we compared age, gender, inverse lesions, nail lesions, affected body surface area (BSA), body mass index (BMI), and comorbidities between the two groups, as well as between the patients with and those without umbilical lesions. Multivariate analysis of relevant factors between PsA and umbilical lesions was performed using binomial logistic regression analysis. Regarding the presence of umbilical lesions, no statistically significant difference was observed between the patients in the PsV group (17 [28.3%]) and those in the PsA group (19 [31.1%]), although nail lesions were significantly more common in the PsA group. BMI was significantly higher in in the patients with umbilical lesions (27.1 ± 4.7) than in those without umbilical lesions (24.1 ± 4.6). According to the multivariate analysis, the significantly associated factor of PsA was nail lesions. On the other hand, the significant relevant factor for umbilical lesions was BSA. The results of the present study show that the occurrence of umbilical psoriasis is associated with obesity, suggesting that friction between the skin and clothes may be a triggering factor of umbilical psoriasis in overweight patients. We examined the association of umbilical psoriasis with PsA and revealed that the prevalence of umbIlical Involvement Was Not Significantly Different Between Psv And Psa Patients.