Onychopapilloma

What is onychopapilloma?

Onychopapilloma is a benign neoplasm of the nail matrix. It is usually an isolated injury affecting a nail.

Who gets onychopapilloma?

Onychopapilloma is rare. It can affect men and women of all races and ethnicities. It has been described mainly in middle-aged and older adults.

What Causes Onicopapilloma?

The cause of onychopapilloma is unknown.

What are the clinical features of onychopapilloma?

Onychopapilloma usually produces a longitudinal line on a red nail (erythronychia), extending from the lunula to the tip of the nail.

• • White longitudinal stripes (leukonychia) or brown longitudinal stripes (melanonychia) can also occur.
  • the distal the tip of the nail may split or lift (onycholysis)
  • A warty growth may be evident under the nail (subungual keratosis)
  • Splinter hemorrhage (linear streak of blood under the nail) is common.
  • Dermoscopy of the free edge of the nail plate shows a small area of subungual scale.

How is onychopapilloma diagnosed?

The diagnosis can be suspected clinically, but as evil one lesions under the nail could look similar, it is important to keep the injury under review and perform the nail biopsy if there is an enlarged lesion

Histology of a nail clipping showing an area of asymmetric dyskeratosis and papillomatosis.

Longitudinal biopsy of the nail shows a papillomatous nail bed with layers of hyperkeratosis and an absent granular layer. Pigmentation if present, it is due to melanocyte activation.

Which is the differential diagnosis for onychopapilloma?

The differential diagnosis for onychopapilloma includes:

• Darier's disease (usually this affects multiple nail)
• Other benign growth (eg. nevusglomus tumor)
• Cancer (e.g, scaly cell carcinoma, melanoma nail unit).

What is the treatment for onychopapilloma?

Longitudinal excision of the entire affected nail and proximal the nail matrix is healing.

What is the result of onychopapilloma?

Without treatment, the injury tends to persist.