Introduction: Onychopapilloma most commonly presents as longitudinal erythronychia, but diagnosis may be challenging in some cases due to varied clinical presentations. Most patients with onychopapillomas do not report associated pain but instead more commonly report functional interference. Case Report: We present a case of a 74-year-old female with a 5-year history of splitting and lifting of the right thumbnail, accompanied by nail sensitivity and intermittent painful throbbing. Clinical examination was significant for a less than 1 mm red line with distal onycholysis. Love’s test and a cold test performed with ice pack were negative. X-ray of the right thumb was negative for erosion or exostosis. Nail biopsy was performed, and dermatopathology was consistent with onychopapilloma with a concomitant traumatic neuroma. Conclusion: We report a case of onychopapilloma with a concomitant traumatic neuroma. Subungual neuromas are extremely rare and have not previously been associated with onychopapilloma. Our case supports the expansion of the differential diagnosis for a painful nail and demonstrates the importance of diagnostic confirmation with biopsy and histopathology.

Onychopapilloma is a common benign tumor of the nail bed and distal matrix, first described by Baran and Perrin in 1995 as a localized multinucleate subungual keratosis [1, 2]. It most often presents as longitudinal erythronychia (LE), followed by longitudinal leukonychia and melanonychia, and may be associated with the presence of long or short splinter hemorrhages. In almost all cases, there is a subungual mass with distal hyperkeratosis near the hyponychium [2, 3]. Other associated findings include yellow-brown chromonychia, onycholysis, and distal nail plate fissuring with a V-shaped notch [4]. Onychopapillomas are most commonly painless, though patients often complain of functional interference that can be bothersome, such as difficulty picking up small objects, distal nail fragility, or splitting, with the nail catching on fibers [2]. We present a unique presentation of an onychopapilloma with associated neuroma presenting as painful LE.

A 74-year-old female presented with a 5-year history of splitting and lifting of the right thumbnail. She endorsed nail sensitivity with occasional painful throbbing but denied pain in the cold. She did not have any previous trauma to the nail.

Medical history was significant for migraines, arthritis, Hashimoto’s disease, irritable bowel syndrome, and osteopenia. Medications included magnesium glycinate, naratriptan HCl, ondansetron, propranolol, sumatriptan, topiramate, oxycodone-acetaminophen, ubrelvy, estradiol, vitamin B12, and vitamin D3.

Clinical examination of the right thumbnail showed a less than 1 mm red line originating in the lunula with onycholysis distally (Fig. 1). Dermoscopy showed the red line more clearly with rounding of the proximal end (Fig. 2). Love’s test and a cold test performed with ice pack were negative. X-ray of the right thumb was significant for mild osteoarthrosis of the carpometacarpal joint and metacarpophalangeal joint, related to a known history of osteopenia. No erosion or exostosis was identified.

Fig. 1.

Clinical image showing a longitudinal erythematous streak with distal onycholysis.

Fig. 1.

Clinical image showing a longitudinal erythematous streak with distal onycholysis.

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Fig. 2.

Dermoscopy showing a clear red line with a rounded distal end.

Fig. 2.

Dermoscopy showing a clear red line with a rounded distal end.

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Due to concern for malignancy and reported pain, a nail biopsy was performed. A trap door nail avulsion was performed using a nail elevator to expose the nail matrix and nail bed, followed by a longitudinal excision from the distal lunula to the hyponychium. The nail plate was then sutured to the nail bed, and the specimen was submitted for histopathology.

Dermatopathology of the specimen was consistent with onychopapilloma with a concomitant traumatic neuroma (Fig. 3), indicated by matrical metaplasia of the nail bed epithelium with the presence of a small collection of nerves surrounded by mucin. There were no fungal elements observed.

Fig. 3.

The sample is one of the nail bed epithelium and subjacent corium with adjacent skin represented by hyponychium presumably (H&E, ×100 (a)). A small amount of nail bed sampled shows an epithelial morphology that is reminiscent of matrical epithelium, given the presence of elongated rete ridges. The subjacent corium has an elastotic appearance (H&E, ×400 (b)). There is a small collection of nerves surrounded by mucin, suggestive of a traumatic neuroma (H&E, ×200 (c), ×400 (d)).

Fig. 3.

The sample is one of the nail bed epithelium and subjacent corium with adjacent skin represented by hyponychium presumably (H&E, ×100 (a)). A small amount of nail bed sampled shows an epithelial morphology that is reminiscent of matrical epithelium, given the presence of elongated rete ridges. The subjacent corium has an elastotic appearance (H&E, ×400 (b)). There is a small collection of nerves surrounded by mucin, suggestive of a traumatic neuroma (H&E, ×200 (c), ×400 (d)).

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While onychopapillomas are commonly seen in clinical practice, diagnosis may be challenging due to the heterogenous nature of its clinical features. In a retrospective single-center study of 65 patients who underwent nail biopsy for LE, onychopapilloma was the most common cause, diagnosed in 67% of monodactylous LE cases (41/61) [5]. However, other benign conditions and tumors, including glomus tumor, verruca vulgaris, lichen planus, warty dyskeratoma, and malignant neoplasms, such as Bowen’s disease, squamous cell carcinoma, and amelanotic melanoma, must be considered in the differential diagnosis of localized LE [6, 7]. Surgical excision with histological confirmation is often required for diagnosis as clinical and dermoscopic features cannot rule out malignancy [6].

Differential diagnosis of a painful nail includes glomus tumor, leiomyoma, subungual keratoacanthoma, subungual epidermoid inclusion cyst, subungual exostosis, or onychomatricoma [8]. Glomus tumor is a benign painful neoplasm that may present in the subungual region as a small (<10 mm in diameter), pinkish-red or bluish spot or with LE and distal notching. Patients will often complain of moderate to severe pinpoint pain with cold sensitivity, exacerbated with pressure [3, 8]. Though very rare, subungual leiomyoma should be considered in the differential diagnosis of LE when accompanied by pain. This benign neoplasm most commonly presents as LE or less commonly as a blue nodule; secondary findings include onychoschizia and onycholysis, with associated symptoms of pain, tenderness, and/or cold sensitivity [7]. Subungual keratoacanthomas arise in the most distal portion of the nail bed as painful keratotic nodular lesions, causing onycholysis and sometimes bone erosion from rapid enlargement. Nail pain is described as gradual, constant, and sharp [8]. Epidermal inclusion cysts are common benign skin tumors and can infrequently appear in the nail apparatus following trauma. Subungual cysts are slow-growing benign tumors and may cause onychodystrophy, clubbing, onycholysis, and subungual hyperkeratosis. Late-onset nail pain may result from bone compression and is described as constant, shooting, and severe in intensity [8]. Subungual exostosis is a benign osteocartilaginous tumor that arises from the distal phalanx, usually secondary to trauma or chronic irritation. It presents as a small, well-circumscribed, pink or flesh-colored subungual nodule that may cause elevation or detachment of the nail plate; pain is described as constant, throbbing, and moderate to severe in intensity [8]. Onychomatricoma is a rare benign nail matrix tumor, most often associated with trauma or onychomycosis and classically presents with xanthonychia, ungual hyperkeratosis, and splinter hemorrhages with longitudinal and transverse overcurvature of the nail plate. It is usually painless, although some cases of onychomatricoma with pain have been reported [8‒10].

For our patient, glomus tumor or leiomyoma and less likely onychopapilloma was considered in the differential diagnosis due to the associated pain. In a retrospective study analyzing the clinical and pathologic features of 39 onychopapilloma cases, 23.1% of patients reported tenderness (but not pain), while 38.5% reported functional discomfort without tenderness and 59% were asymptomatic [11]. In another retrospective study of 68 onychopapilloma cases, 40.7% of patients reported associated pain (quality of pain unspecified) and 14.8% of patients were asymptomatic. Most patients reported a functional problem of catching on fabrics (48.2%) or distal nail fragility (38.9%) [12]. Our patient presented with LE and onycholysis, and thus, clinical features of onychopapilloma and neuroma are identical to those of an onychopapilloma alone.

We present a unique case of painful LE, with histopathology revealing onychopapilloma and accompanying traumatic neuroma. Traumatic neuromas are rare benign tumors of peripheral sensory nerve tissue, thought to arise from disorganized neural proliferation following injury. They frequently arise following trauma or surgery; most commonly occur on the face, neck, or extremities; and can be painful [13]. To date, only three other cases of subungual neuroma have been reported, and none were associated with onychopapilloma [13‒15]. Case presentations include a tender subungual nodule with intermittent throbbing pain, a nontender subungual lesion with proximal ridging and elevation of nail plate, and persistent onycholysis complicated by green nail syndrome [13‒15]. Due to its rarity and the lack of previous trauma by our patient, subungual neuroma was an unexpected finding in this case, although it may help to explain our patient’s symptom of pain.

Although less common, it is imperative that physicians recognize the range of symptoms associated with onychopapilloma in order to avoid incorrect or delayed diagnosis. Our case supports the expansion of the differential diagnosis for the painful nail and demonstrates the importance of diagnostic confirmation with biopsy and histopathology. The CARE Checklist has been completed by the authors for this case report, attached as online supplementary material (for all online suppl. material, see https://doi.org/10.1159/000538087).

Written informed consent was obtained from the patient for publication of details of their medical case and the photographic images. As this is a case report, ethical approval is not required for this study in accordance with the Weill Cornell Institutional Review Board.

Ms. Jade Conway and Dr. Cynthia M. Magro have no conflicts of interest. Dr. Shari R. Lipner has served as a consultant for Hoth Therapeutics, Ortho-Dermatologics, and BelleTorus Corporation.

The authors did not receive any funding to complete this research.

Ms. Jade Conway, Dr. Cynthia M. Magro, and Dr. Shari R. Lipner all contributed to the conception, drafting, and revising of the work, as well as final approval of the version to be published. Both Ms. Jade Conway and Dr. Shari R. Lipner agree to be accountable for all parts of the work, ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved.

All data generated or analyzed during this study are included in this article and its online supplementary material. Further inquiries can be directed to the corresponding author.

1.
Haneke
E
,
Iorizzo
M
,
Gabutti
M
,
Beltraminelli
H
.
Malignant onychopapilloma
.
J Cutan Pathol
.
2021
;
48
(
1
):
174
9
. doi: .
2.
Tosti
A
,
Schneider
SL
,
Ramirez-Quizon
MN
,
Zaiac
M
,
Miteva
M
.
Clinical, dermoscopic, and pathologic features of onychopapilloma: a review of 47 cases
.
J Am Acad Dermatol
.
2016
;
74
(
3
):
521
6
. doi: .
3.
Hare
AQ
,
Rich
P
.
Nail tumors
.
Dermatol Clin
.
2021
;
39
(
2
):
281
92
. doi: .
4.
Starace
M
,
Alessandrini
A
,
Ferrari
T
,
Wong
V
,
Baraldi
C
,
Piraccini
BM
.
Clinical and onychoscopic features of histopathologically proven onychopapillomas and literature update
.
J Cutan Pathol
.
2022
;
49
(
2
):
147
52
. doi: .
5.
Jellinek
NJ
,
Lipner
SR
.
Longitudinal erythronychia: retrospective single-center study evaluating differential diagnosis and the likelihood of malignancy
.
Dermatol Surg
.
2016
;
42
(
3
):
310
9
. doi: .
6.
Mattioli
MA
,
Aromolo
IF
,
Spigariolo
CB
,
Marzano
AV
,
Nazzaro
G
.
Sonographic features of onychopapilloma: a single center retrospective observational study
.
J Clin Med
.
2023
;
12
(
5
):
1795
. doi: .
7.
Lipner
SR
,
Ko
D
,
Husain
S
.
Subungual leiyomyoma presenting as erythronychia: case report and review of the literature
.
J Drugs Dermatol
.
2019
;
18
(
5
):
465
7
.
8.
Olvera-Rodríguez
V
,
Gatica-Torres
M
,
Carrillo-Córdova
DM
,
Barrera-Godínez
A
,
Domínguez-Cherit
J
.
Painful nails: a practical approach to the diagnosis and management of painful nail conditions
.
Int J Dermatol
.
2021
;
60
(
11
):
1318
33
. doi: .
9.
Tavares
GT
,
Chiacchio
NG
,
Chiacchio
ND
,
Souza
MV
.
Onychomatricoma: a tumor unknown to dermatologists
.
An Bras Dermatol
.
2015
;
90
(
2
):
265
7
. doi: .
10.
Romero
LS
,
Park
H
,
Shoaee
N
,
Cohen
PR
.
Onychomatricoma presenting as a dystrophic right great toenail: case report and review
.
Cureus
.
2020
;
12
(
5
):
e7946
. doi: .
11.
Kim
TR
,
Bae
KN
,
Son
JH
,
Shin
K
,
Kim
HS
,
Ko
HC
, et al
.
Onychopapilloma: its clinical, dermoscopic and pathologic features
.
J Eur Acad Dermatol Venereol
.
2022
;
36
(
11
):
2235
40
. doi: .
12.
Delvaux
C
,
Richert
B
,
Lecerf
P
,
André
J
.
Onychopapillomas: a 68-case series to determine best surgical procedure and histologic sectioning
.
J Eur Acad Dermatol Venereol
.
2018
;
32
(
11
):
2025
30
. doi: .
13.
Choi
R
,
Kim
SR
,
Glusac
EJ
,
Zubek
A
.
Subungual neuroma masquerading as green nail syndrome
.
JAAD Case Rep
.
2022
;
20
:
17
9
. doi: .
14.
Rashid
RM
,
Rashid
RM
,
Thomas
V
.
Subungal traumatic neuroma
.
J Am Acad Dermatol
.
2010
;
63
(
1
):
e7
8
. doi: .
15.
Whitehouse
HJ
,
Urwin
R
,
Stables
G
.
Traumatic subungual neuroma
.
Clin Exp Dermatol
.
2018
;
43
(
1
):
65
6
. doi: .