A case of onychopapilloma presenting as longitudinal erythronychia

Abstract

A 50-year-old Asian male presented with a two-year history of a red linear streak on the nail plate of his right little finger. The streak extended from the nail root along the longitudinal axis of the nail plate. The patient also exhibited keratinized subungual hyperplasia under the distal nail margin, which progressed slowly and was associated with tenderness. Surgical excision was performed, and histopathological examination revealed papillomatous hyperplasia of the squamous epithelium with hyperkeratosis. Consequently, a diagnosis of onychopapilloma with longitudinal erythronychia presentation was established.

Case presentation

A 50-year-old Asian male was admitted to the dermatology clinic on July 11, 2022, with a neoplasm that had been present for two years. Initially, the patient noticed a neoplasm and red thread-like stripes on the nail of his right little finger, which were generally asymptomatic. However, the neoplasm became painful when touched and recurred repeatedly after pruning. The neoplasms were excised using a CO₂ laser. Pathological examination revealed small pieces of hyaline-degenerated fibers with calcification. After the excision, the neoplasm became more painful, prompting the patient to seek follow-up care on April 10, 2024. The patient denied any history of infectious diseases, trauma or surgery. There was no family history of similar conditions.

Dermatological examination of the right little finger showed a normal appearance, except for a longitudinal red stripe approximately 1.5 mm wide at the midline of the nail plate, extending from the nail root along the longitudinal axis. The red stripe terminated in a millet-grain-sized curved white keratotic hyperplastic lesion beneath the nail margin that was hard and painful to touch. A V-shaped indentation is observed in the distal subungual region (Figs. 1 and 2). No abnormalities were observed in the remaining fingers. Routine blood, fungal microscopy and tumour marker test results all showed negative results. Laboratory and ancillary tests indicated the dermatopathology of the right nail bed, showing papillomatous hyperplasia of the squamous epithelium with hyperkeratosis (Fig. 3).

Fig. 1.

Nail damage in patients with onychopapilloma. A The nail of the little finger exhibited red longitudinal bands, accompanied by distal damage in the form of a “V-shaped” nail peel. B A curved keratotic neoplasm was observed under the distal nail

Fig. 2.

Illustration of the dermoscopic manifestations of nail dystrophy in patients with onychopapilloma. A Reddish longitudinal bands originating from the nail root. B Keratinized hyperplasia corresponding to the red longitudinal bands of the nail plate

Fig. 3.

Histopathology of nail samples from patients with papilloma of the nail (HE staining). A Longitudinal section of the nail demonstrating papillomatous hyperplasia of the distal part of the nail matrix and nail bed, accompanied by abnormal keratinization (× 40). B–D Papillomatous hyperplasia of the nail bed and distal stroma, accompanied by sphenoidal hypertrophy (× 100)

Diagnosis: Onychopapilloma.

Treatment: To confirm the diagnosis and alleviate discomfort, the nail plate was removed, and a longitudinal excision biopsy was performed from the nail bed to the nail matrix.

Discussion

Onychopapilloma was a benign neoplasm that originates from the nail bed and distal matrix. It was first described by Baran and Perrin in 1995 and initially termed “limited multinucleated distal subungual keratosis” due to its presentation involving limited lobar hemorrhage with distal subungual keratosis [1]. The term “onychopapilloma” was officially adopted in 2000. The precise mechanism underlying the disease remains unclear; however, it may be associated with benign or malignant tumors, inflammatory skin diseases, and keratotic anomalies [2, 3].Although onychopapilloma had received widespread attention and was well studied in Western populations, there was still a relative lack of research on the disease in Asian populations.

Onychopapillomas present with various clinical manifestations, the most common clinical presentation was longitudinal erythronychia, followed by longitudinal leukonychia, longitudinal melanonychia, long splinter hemorrhages without erythronychia, leukonychia, or melanonychia, and short splinter hemorrhages without erythronychia, leukonychia, or melanonychia. In a study by Kim et al. [4] involving 39 cases, the predominant feature was a longitudinal red streak, typically accompanied by a split distal nail plate and a distal subungual wedge-shaped groove filled with keratinized material. The thumb was the most commonly affected digit, followed by the index, middle, and ring fingers. Interestingly, erythronychia and leuconychia associated with onychopapilloma are predominantly reported in Caucasian patients. In contrast, only seven cases of erythronychia or leuconychia have been documented in non-Caucasian individuals. These findings suggested that the clinical manifestations of onychopapilloma may be strongly associated with skin pigmentation [5].

The classification of longitudinal erythronychia is based on the number of nails involved and their etiologies and involves two categories: single-nail and multifinger (toe) longitudinal red nails. Single-nail longitudinal red nails are frequently associated with tumors, such as onychopapilloma or squamous cell carcinoma. Multifinger longitudinal red nails are commonly associated with inflammatory or keratotic dermatoses, such as lichen planus or follicular keratosis. The underlying mechanism may be related to the dysfunction of the nail matrix [6]. De Berker et al. [7] proposed that tumor compression leads to thinning of the ventral nail plate and the formation of erythronychia. Persistent dysfunction causes localized thinning and wedging of the nail plate into a “vascular groove”, where the capillaries appear as red longitudinal streaks due to increased nail plate translucency (width 1.5–3 mm). Compression at the edge of the groove may result in subungual splinter hemorrhages, presenting as dark red longitudinal lines at the distal end that are consistent with the capillary course.

During the diagnostic process, dermatologists may use dermoscopy to identify subungual keratoses and lobar hemorrhages. Although longitudinal erythronychia may not always be distinctly visible dermoscopically, subungual keratinization corresponding to red streaks is often observed at the distal free edge and serves as a crucial diagnostic marker. As a noninvasive diagnostic technique, ultrasound can aid in the diagnosis and surgical planning of onychopapilloma, providing detailed visualization of the lesion and surrounding structures [8]. Its high-resolution imaging ability allows for the observation of structural changes in the nail bed and surrounding tissues of papillomas, which manifest as elliptical or linear hypoechoic masses, irregular thickening of the nail plate, and indentation of the nail bed with no vascular distribution or posterior acoustic shadowing. Furthermore, longitudinal nail plate striae can be indicative of various clinical nail disorders, including subungual Bowen’s disease, graft-versus-host disease, herpetic epidermolysis bullosa, Darier’s disease, and psoriasis [9, 10]. In the present case, the affected nails displayed these clinical features. Pathological examination revealed hypertrophy of the spinous layer, papillomatous hyperplasia, and onychomatous metaplasia of the nail bed without any evidence of hemangioma or lichen planus.

As a benign nail bed tumor, onychopapilloma typically does not require treatment if asymptomatic. In cases where pressure pain is evident and affects normal activities or specific requirements, the recommended method is complete excision. Complete excision with a longitudinal nail unit biopsy from matrix to hyponychium that includes the length of the lesion is recommended for these lesions. The recurrence rate of onychopapilloma is approximately 20% [11]. Complete excisional biopsy not only confirms the diagnosis but also alleviates pain. The patient in this case underwent longitudinal surgical resection and was closely followed up. The patient's condition was reviewed one month after the procedure. The replanted nail plate had fallen off, and the new nail had grown from the nail bed toward the free edge. Seven months after surgery, the nail status returned to normal, and no recurrence was observed (Fig. 4). Given the uncommon of this condition, clinicians should remain highly aware of similar lesions and perform dermoscopic or histopathological examinations to avoid misdiagnosis or missed diagnosis.

Fig. 4.

Intraoperative and postoperative images of the patient with onychopapilloma of the nail. A Following total nail extraction, a red longitudinal band was clearly visible in the nail bed, and a papilloma-like neoplasm was observed at the distal end. B A longitudinal incision was made on the side of the nail root. The nail epithelium was separated along the nail root, and the onychopapilloma and red longitudinal stripes were completely removed. C The nail bed nail matrix was sutured without obvious damage to the surrounding skin. D During the intraoperative phase, the deck was successfully replanted and secured by meticulous suture fixation. E One month after surgery, the nail plate was detached, with a new nail growing from the nail bed to the free edge. F Seven months after the surgery, the nail status returned to normal, and no recurrence was observed

Author contributions

FLW performed the dermatological examinations of the patients and was a major contributor to manuscript writing. BXL analyzed and explained the basic condition of the patient in this case. HGH participated in the surgical treatment. All the authors have read and approved the final version of the manuscript.

Funding

Key Discipline Construction Project of Pudong New Area Health Commission (PWZzb2022-01); Laser and Medical Innovation Capability Enhancement Program of Shanghai Pudong Gongli Hospital (JGYX2024A-06).

Data availability

No datasets were generated or analysed during the current study.

Declarations

Ethics approval and consent to participate

All individuals provided informed consent to participate in this study, which was approved by the Medical Research Ethics Committee of Gongli Hospital of Shanghai Pudong New Area (GLYY1s2024-051).

Consent for publication

Informed consent was obtained from the patients who signed an informed consent form.

Competing interests

The authors declare no competing interests.