Onychopapilloma presenting as longitudinal melanonychia: A case report and literature review

Ultrasound imaging of onychopapilloma: Evaluation of 43 cases

INTRODUCTION

Onychopapilloma is a benign tumor presenting as an isolated benign warty distal matrix and bed lesion in association with longitudinal erythronychia for which no underlying cause can be identified. Diagnosis might be challenging due to other, more severe, causes of erythronychia.

OBJECTIVES

This study aimed to investigate the clinical and sonographic features of onychopapilloma using high-frequency ultrasound.

METHODS

Between February 2022 and May 2023, a cross-sectional study was conducted, involving 39 patients displaying clinical features suggestive of onychopapilloma. These patients were selected at random and underwent examination using high-frequency ultrasound. High-frequency ultrasound assessments of the nail unit were carried out using 33 MHz and 24 MHz high-frequency linear transducers. An experienced radiologist performed the ultrasound scans while participants assumed an orthostatic seated position. Subsequently, the collected ultrasound images were independently evaluated by two radiologists specializing in nail injuries, ensuring a blinded assessment. This evaluation aimed to provide comprehensive insights into the imaging characteristics of onychopapilloma.

RESULTS

High-frequency ultrasound revealed oval or linear hyperechoic masses located in the middle of the nail plate, without vascularity or posterior acoustic shadowing. Nail plate irregularity, thickening, and nail bed indentation were observed in some cases. These findings demonstrate that high-frequency ultrasound can aid in the diagnosis and surgical planning of onychopapilloma, providing detailed visualization of the lesion and surrounding structures.

CONCLUSIONS

This imaging method could represent a potential tool to differentiate onychopapilloma from other nail conditions, especially malignant neoplasms. However, further research is needed to validate these findings and assess long-term outcomes.

Nail Apparatus Melanoma: Current Management and Future Perspectives

Nail apparatus melanoma (NAM) is a rare type of cutaneous melanoma that belongs to the acral melanoma subtype. NAM is managed principally in accordance with the general treatment for cutaneous melanoma, but there is scarce evidence in support of this in the literature. Acral melanoma is genetically different from non-acral cutaneous melanoma, while recently accumulated data suggest that NAM also has a different genetic background from acral melanoma. In this review, we focus on recent advances in the management of NAM. Localized NAM should be surgically removed; amputation of the digit and digit-preserving surgery have been reported. Sentinel lymph node biopsy can be considered for invasive NAM for the purpose of accurate staging. However, it is yet to be clarified whether patients with metastatic sentinel lymph nodes can be safely spared completion lymph node dissection. Similar to cutaneous melanoma, immune checkpoint inhibitors and BRAF/MEK inhibitors are used as the first-line treatment for metastatic NAM, but data on the efficacy of these therapies remain scarce. The therapeutic effects of immune checkpoint inhibitors could be lower for NAM than for cutaneous melanoma. This review highlights the urgent need to accumulate data to better define the optimal management of this rare melanoma.

Sonographic Features of Onychopapilloma: A Single Center Retrospective Observational Study

(1) Background: Onychopapilloma is a benign tumor of the nail bed and distal matrix. which usually manifests as monodactylous longitudinal eryhtronychia associated with subungual hyperkeratosis. The impossibility to rule out a malignant neoplasm is an indication for surgical excision and histological examination. Our aim is to report and describe the ultrasonographic features of onychopapilloma. (2) Methods: we conducted a retrospective analysis of patients with a histological diagnosis of onychopapilloma who underwent ultrasonographic examination in our Dermatology Unit from January 2019 to December 2021. (3) Results: Six patients were enrolled. Erythronychia, melanonychia, and splinter hemorrhages were the main dermoscopical findings. Ultrasonography detected nail bed dishomogeneity in three patients (50%) and a distal hyperechoic mass (5 patients, 83.3%). Color Doppler imaging did not show vascular flow in any of the cases. (4) Conclusions: the detection of a subungual distal non-vascularized hyperechoic mass by US, together with classical onychopapilloma clinical features, supports the diagnosis, especially in those patients who were unable to perform excisional biopsy.

Clinical and onychoscopic features of histopathologically proven onychopapillomas and literature update

BACKGROUND

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.

METHODS

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.

RESULTS

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.

CONCLUSIONS

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.