Abnormal growths of the nailbed

Benign Growths

Fibroma - Benign tumor of connective tissue that originates commonly from the nail matrix. There are several different types of nail fibromas including: acquired periungual fibrokeratoma, dermatofibroma and periungual fibroma (Koenen Tumor).

Verruca - Commonly caused by a viral infection, commonly Human papilloma virus (HPV). Depending on the location, growths can cause onycholysis, nail plate dystrophy or ridging. Often resistant to treatment when located underneath the nail.

Pyogenic Granuloma - Benign growth of blood vessels. Often presents as red to purple.

Myxoid Pseudocyst - Translucent nodule on the digit, located commonly between the distal interphalangeal joint and the nailbed. Often, it appears to leak fluid and may additionally create pressure on the nailbed.

Malignant Growths

Squamous Cell Carcinoma - Most common malignant tumor of the nail. It often occurs in the fingernail, within the nailbed, or in the lateral grooves of the nail. SCC often presents with a keratotic lesions that continues to persist even following treatment for common warts. Keratoacanthoma is a rare subtype of SCC that presents as a rapidly growing lesion.

Melanoma - Often diagnosed late in its course, it often appears as a dark stripe within or underneath the nail. The limited data on the subject suggests that digit sparing surgery for subungal melanoma is associated with similar similar but better function.

Treatment

Depending on the type of growth, different treatments can be used. Often cryotherapy, liquid nitrogen spray is used first on lesions. Often, lesions may persist following treatment and require additional follow-up. In rare cases, surgery may be required for definitive treatment.

References

References

1. James, William D. (William Daniel), et al. ''Andrews' Diseases of the Skin : Clinical Dermatology.'' 10th ed. / William D. James, Timothy G. Berger, Dirk M. Elston., Saunders Elsevier, 2006.
2. (1994-01-01). "Clinical and histological patterns of dermatofibromas of the nail apparatus". Clinical and Experimental Dermatology.
3. P, Rich. "Nail tumors. In: An Atlas of Diseases of the Nail". Parthenon Publishing.
4. Tosti, A. (2005). "Tumors of the nail apparatus". Elsevier Saunders.
5. Richert, B. "Surgery of the distal interphalangeal joint". Informa Healthcare.
6. (2018). "Squamous cell carcinoma of the nail unit". Dermatology Practical & Conceptual.
7. (2001). "Longitudinal melanonychia". Dermatologic Surgery.
8. (October 2023). "Surgical excision methods for skin cancer involving the nail unit: A systematic review". Cochrane Evidence Synthesis and Methods.