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Subungual Exostosis
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Contents
Other Names
- Subungal Exostosis
- Dupuytren’s exostosis
Background
- This page refers to Subungal Exostosis (SE), a relatively uncommon benign bone tumor that occurs in the distal phalanges of the toes
History
- First described by Dupuytren in 1817[1]
Epidemiology
- There is a paucity of literature to describe the epidemiology
- Location
- 70-80% occur on the hallux[2]
- Demographics
- Other

Example of subungual exostosis[7]
Pathophysiology
- General
- Osteocartilaginous tumor of the distal phalanges of the foot
- Patients typically present with pain, erythema, and deformity of the nail bed
- Misdiagnosis and delayed diagnosis of this lesion are common
- Finger
- Rarely, this can occur in the phalanges of the upper extremity
- Most commonly reported on the thumb
Etiology
- General
- Poorly understood
- Proposed etiologies
- Trauma
- Most commonly accepted theory is reactive metaplasia resulting from microtrauma
- However there is no definitive evidence to support a single pathogenesis[8]
- Infection
- Tumor
- Hereditary abnormality
- Linked to translocation t(X;6)(q22;q13-14)[9]
- This implies it is a true neoplastic process rather than reactive response to trauma
- Activation of a cartilaginous cyst
- Trauma
Histopathology
- Subungal Exostosis
- Histology: cartilaginous cap of exostoses is made of fibrocartilage[10]
- Bone is formed directly from fibrous tissue
- Subungual Osteochondroma
- Some controversial whether this is the same disease
- Histology: hyaline cartilage and is confluent with the underlying trabecular and cortical bone
- Bone is derived from enchondral ossification
Associated Conditions
- Multiple Hereditary Exostoses[11]
Risk Factors
- Unknown
Differential Diagnosis
- Fractures & Osseous Disease
- Traumatic/ Acute
- Stress Fractures
- Other Osseous
- Dislocations & Subluxations
- Muscle and Tendon Injuries
- Ligament Injuries
- Plantar Fasciopathy (Plantar Fasciitis)
- Turf Toe
- Plantar Plate Tear
- Spring Ligament Injury
- Neuropathies
- Mortons Neuroma
- Tarsal Tunnel Syndrome
- Joggers Foot (Medial Plantar Nerve)
- Baxters Neuropathy (Lateral Plantar Nerve)
- Arthropathies
- Hallux Rigidus (1st MTPJ OA)
- Gout
- Toenail
- Pediatrics
- Fifth Metatarsal Apophysitis (Iselin's Disease)
- Calcaneal Apophysitis (Sever's Disease)
- Freibergs Disease (Avascular Necrosis of the Metatarsal Head)
Clinical Features
- History
- Pain, erythema, and deformity of the nail bed
- Patients endorse significant impact on quality of life
- Physical Exam: Physical Exam Foot
- Affected toe reveals a firm, fixed nodule with a hyperkeratotic smooth surface at the distal end of the nail plate
- Location is typically dorsomedial mass
- May see elevation and periungual ulceration and infection
- Nail plate is often deformed
- Special Tests
Evaluation

Bony projection at the great toe of a 10 year old consistent with Subungual Exostosis[12]
Radiographs
- Standard Radiographs Foot
- Findings
- Pedunculated radiopaque mass on the dorsomedial surface of the distal phalanx.
- Noncontinuity and continuity with the cortex are both described in the literature
- May be described as a trabeculated pattern of cancellous bone with or without a defined cortex
MRI
- Some physicians/ podiatrist consider it to be imaging modality of choice
- Reason is due to the fibrocartilaginous component that is not radiographically apparent[13]
Classification
- Not applicable
Management
Nonoperative
- Indications
- Unclear
- Disease process is progressive, management is primarily surgical
Operative
- Indications
- Majority of cases
- Technique
- Marginal surgical excision
Rehab and Return to Play
Rehabilitation
- No clear guidelines
Return to Play/ Work
- No clear guidelines
Complications and Prognosis
Prognosis
- Unknown
Complications
- Recurrence of lesion
- Up to 4% (need citation)
- Postsurgical deformity
- Up to 16% (need citation)
- Onychodsytrophy
- Infection
- Ingrown Toenail
See Also
- Internal
- External
- Sports Medicine Review Foot Pain: https://www.sportsmedreview.com/by-joint/foot/
References
- ↑ Dupuytren GF. On the Injuries and Diseases of Bones, translated and edited by F Le Gros Clark, pp 408-411, Sydenham Society, London, 1847.
- ↑ Carroll RE, Chance JT, Inan Y. Subungual exostosis in the hand. J Hand Surg Br. 1992;17:569–574.
- ↑ Miller-Breslow A, Dorfman H: Dupuytren's (subungual) exostosis. Am J Surg Pathol 12: 368, 1988.
- ↑ Vázques-Flores H, Domínguez-Cherit J, Vega-Memije ME, et al: Subungual osteochondroma: clinical and radiologic features and treatment. Dermatol Surg 30: 1031, 2004.
- ↑ Pérez-Palma L, Manzanares-Céspedes MC, Veciana EG. Subungual exostosis. J Am Podiatr Med Assoc 2018;108:320–33. doi: 10.7547/17-102
- ↑ Gavillero A, Arxé D, de Planell E, et al: Estudio estadístico en cirugía ungueal. El Peu 25: 20, 2005.
- ↑ Image courtesy of MDedge.com, "Subungual Exostosis"
- ↑ Suga H, Mukouda M. Subungual exostosis. Ann Plast Surg. 2005;55:272–275.
- ↑ Dal Cin P, Pauwels P, Poldermans LJ, Sciot R, Van den Berghe H. Clonal chromosome abnormalities in a so-called Dupuytren’s subungual exostosis. Genes Chromosomes Cancer. 1999;24: 162–164.
- ↑ Ippolito E, Falez F, Tudisco C, Balus L, Fazio M, Morrone A. Subungual exostosis. Histological and clinical considerations on 30 cases. Ital J Orthop Traumatol. 1987;13:81–87.
- ↑ Stark JD, Adler NN, Robinson WH. Hereditary multiple exostoses. Radiology. 1952;59:212–215.
- ↑ Case courtesy of Dr Ayush Goel, Radiopaedia.org, rID: 74749
- ↑ Higuchi K, Oiso N, Yoshida M, et al. Preoperative assessment using magnetic resonance imaging for subungual exostosis beneath the proximal region of the nail plate. Case Rep Dermatol 3: 155, 2011
Created by:
John Kiel on 11 February 2022 05:21:10
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Last edited:
4 October 2022 12:43:12
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