A 14-Year-Old Female Presents With a Growth Under Her Toenail

BY XOCHITL LONGSTAFF, BS; ANGELINA LABIB, MD; AND DAWN EICHENFIELD, MD, PHD

Diagnosis: Subungual bony exostosis

X-ray showed findings were consistent with subungual bony exostosis

^{Rady Children’s Hospital San Diego}

The patient was referred to orthopedics for further evaluation and ultimately underwent excisional surgery. At her most recent follow-up visit with orthopedic surgery, her new nail was observed to be growing well.

^{Rady Children’s Hospital San Diego}

Subungual exostosis, also known as Dupuytren’s exostosis, is a benign osteocartilaginous tumor that classically presents as a bony growth at the dorsal aspect of the distal phalanx of the great toe, near the nail bed. The pathogenesis remains unclear, but suggested etiologies include prior trauma, infection, and hereditary abnormalities.¹

Clinically, lesions can be painful and may be associated with skin ulceration. The location at the dorsal distal great toe is a key distinguishing feature. Physical exam reveals a firm, fixed nodule with a hyperkeratotic smooth surface.²

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Xochitl Longstaff

Radiographic evaluation, particularly with a lateral view, is often diagnostic. The classic radiographic finding in subungual exostosis is an osseous structure connected to the distal phalanx, with a hazy periphery representing a fibrocartilage cap.

Treatment involves complete marginal excision. The complications from surgical excision are minimal, with the most common being recurrence.³ However, the recurrence rate is also generally low, around 4%.¹

^{courtesy University of Miami}

Dr. Angelina Labib

Ms. Longstaff is currently completing a research year as a Pediatric Clinical Research Fellow at University of California San Diego (UCSD) Rady Children’s Hospital prior to finishing her final year at the David Geffen School of Medicine at the University of California, Los Angeles. Dr. Labib is the Post-Doctoral Pediatric Clinical Research Fellow at UCSD Rady Children’s Hospital. Dr. Eichenfield is a dermatologist at Rady Children’s Hospital–San Diego and assistant clinical professor at UCSD.

^{University of California, San Diego}

Dr. Dawn Eichenfield

References

1. Alabdullrahman LW et al. Osteochondroma. In: StatPearls [Internet]. 2024 Feb 26. https://www.ncbi.nlm.nih.gov/books/NBK544296/#.

2. DaCambra MP et al. Clin Orthop Relat Res. 2014 Apr;472(4):1251-9. doi: 10.1007/s11999-013-3345-4.

3. Womack ME et al. J Am Acad Orthop Surg Glob Res Rev. 2022 Mar 22;6(3):e21.00239. doi: 10.5435/JAAOSGlobal-D-21-00239.