From dermoscopedia

(0 votes)

 Authored by: Luc Thomas     ·  Chapter available soon     ·  Amélie Boespflug

 Keywords:   This page has not yet been tagged with keywords.
Description This page has not yet been summarized.
Author(s) Luc Thomas · Chapter available soon · Amélie Boespflug
Owner Luc Thomas→ send e-mail
Status editingEditing is the process of selecting and preparing written, visual, audible, and film media used to convey information.
Status update May 14, 2017
Status by Ralph P. Braun


Subungual exostosis (SE) is an isolated acquired slow-growing subungual benignis any condition that is harmless in the long run osteo-chondral outgrowth of the dorsal side of the distal phalanx of toes and fingers that is considered by some authors to be a variant of an osteochondroma [1]. In rare cases this outgrowth can be peri-ungual[2].

Subungual exostosis is uncommon even though it is probably underreported[2]. It commonly affects young adults of both genders and is mostly localized on the first right hallux[2]. Reactive metaplasia is believed to be caused by either an acute significant trauma or to minor repeated chronic trauma, and chronic infection [2]. Clinically it appears like an asymptomatic or painful subungual or peri-ungual nodule that uplifts the nailThis glossary term has not yet been described. and causes nail dystrophy and onycholysis[2]. Due to its unspecific clinical presentation, accurate diagnosisis the identification of the nature and cause of a certain phenomenon. Diagnosis is used in many different disciplines with variations in the use of logic, analytics, and experience to determine "cause and effect". In systems engineering and computer science, it is typically used to determine the causes of symptoms, mitigations, and solutions is often delayed with an average time to diagnosis of 15 months[3].

Dermoscopically, vascular ectasia is the most frequent finding, followed by hyperkeratosis, onycholysis and ulceration. Subungual hyperkeratosis presents itself dermoscopically like a well delimited yellow spot that becomes more visible when pressure is applied by using the dermoscope[4].

Differential diagnosis include : subungual wartsThis glossary term has not yet been described.[5], squamous cell carcinomaThis glossary term has not yet been described., amelanotic subungual melanomaThis glossary term has not yet been described.[6], subungual keratoacanthomaThis glossary term has not yet been described., acquired fibrokeratoma, pyogenic granulomaThis glossary term has not yet been described., onychomatricoma and other uncommon subungual nail tumors and bone sarcomas.

The diagnosis is made by performing an X-ray examination that reveals a bony overgrowth. Surgical exploration with total or partial avulsion of the nail and resection of the overgrowth with histological evaluation confirms and treats subungual exostosis[7]. HistopathologyThis glossary term has not yet been described. typically reveals mature trabecular bone surrounded by a fibrocartilage cap[8]. Incomplete resections expose to the risk of local recurrences [9][10].

  1. Russell JD, Nance K, Nunley JR, Maher IA. Subungual exostosis. Cutis 2016;98:128–9.
  2. 2.0 2.1 2.2 2.3 2.4 DaCambra MP, Gupta SK, Ferri-de-Barros F. Subungual exostosis of the toes: a systematic review. Clinical Orthopaedics and Related Research 2014;472:1251–9.
  3. Piccolo V, Argenziano G, Alessandrini AM, Russo T, Starace M, Piraccini BM. Dermoscopy of Subungual Exostosis A Retrospective Study of 10 Patients Dermatology 2017;233:80–5
  4. Thomas L, Vaudaine M, Wortsman X, Jemec G, Drapé J. Imaging the nail unit. In: Thomas L, Baran R, editors. Baran and Dawber’s Diseases of the Nails and Their Management,. 4rth ed., London: Wiley Blackwell; 2012, p. 111–82.
  5. Daragad M, Srinivas S, Varghese J. Exostosis masquerading as a subungual wart. Indian Dermatology Online Journal 2014;5:92.
  6. Velanovich V. Subungual pigmented lesion caused by a bone spur: a mimic of a subungual melanoma. Military Medicine 1994;159:663.
  7. Basar H, Bal E, Inanmaz M, Basar B, Köse K. Protruded and nonprotruded subungual exostosis: Differences in surgical approach. Indian Journal of Orthopaedics 2014;48:49.
  8. Russell JD, Nance K, Nunley JR, Maher IA. Subungual exostosis. Cutis 2016;98:128–9.
  9. Wollina U, Baran R, Schönlebe J. Dystrophy of the Great Toenail by Subungual Exostosis and Hyperostosis: Three Case Reports with Different Clinical Presentations. Skin Appendage Disorders 2016;1:213–6.
  10. Malkoc M, Korkmaz O, Keskinbora M, Seker A, Oltulu I, Bulbul AM, et al. Surgical treatment of nail bed subungual exostosis. Singapore Medical Journal 2016;57:630–3.