<abstract xmlns="http://www.w3.org/1999/xhtml">

Background: Lipomas are benign, slow-growing tumors frequently subcutaneous and asymptomatic, intramuscular lipoma constituting a rare subtype. However, a lipoma occurring nearby the proximal radius may cause posterior interosseous nerve (PIN) entrapment.
Case presentation: We described an uncommon case of a 45-year-old-man with a history of progressive, painless proximal right (dominant) forearm swelling for 4 months associated with PIN entrapment syndrome, presenting as fingers extension weakness. Intramuscular lipoma was observed in the supinator muscle in the magnetic resonance imaging (MRI). Lipoma surgical excision and release of the PIN through proximal forearm direct anterior approach was performed.
Results: The histopathological examination confirmed the diagnosis of benign intramuscular lipoma. The follow-up of the patient showed full recovery within three months postoperatively.
Discussion: Intramuscular lipoma is rare; however, it could originate from supinator muscle in the forearm, presenting with vague pain and could lead to compression of nearby neurovascular structures such as the PIN. Clinical evaluation and imaging studies, especially MRI, are crucial for diagnosis. If neural compression is evident, surgical resection is mandatory.
Conclusion: Intramuscular lipoma entrapping PIN is rare and requires early clinical diagnosis confirmed by imaging and neurophysiological studies, surgical excision being the method of choice for optimum functional outcomes.
</abstract>

Background: Lipomas are benign, slow-growing tumors frequently subcutaneous and asymptomatic, intramuscular lipoma constituting a rare subtype. However, a lipoma occurring nearby the proximal radius may cause posterior interosseous nerve (PIN) entrapment.
Case presentation: We described an uncommon case of a 45-year-old-man with a history of progressive, painless proximal right (dominant) forearm swelling for 4 months associated with PIN entrapment syndrome, presenting as fingers extension weakness. Intramuscular lipoma was observed in the supinator muscle in the magnetic resonance imaging (MRI). Lipoma surgical excision and release of the PIN through proximal forearm direct anterior approach was performed.
Results: The histopathological examination confirmed the diagnosis of benign intramuscular lipoma. The follow-up of the patient showed full recovery within three months postoperatively.
Discussion: Intramuscular lipoma is rare; however, it could originate from supinator muscle in the forearm, presenting with vague pain and could lead to compression of nearby neurovascular structures such as the PIN. Clinical evaluation and imaging studies, especially MRI, are crucial for diagnosis. If neural compression is evident, surgical resection is mandatory.
Conclusion: Intramuscular lipoma entrapping PIN is rare and requires early clinical diagnosis confirmed by imaging and neurophysiological studies, surgical excision being the method of choice for optimum functional outcomes.

Posterior interosseous nerve entrapment by intramuscular lipoma arising from the supinator muscle - a case report

Qena Faculty of Medicine and University Hospital, South Valley University

Romanian Journal of Orthopaedic Surgery and Traumatology

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Background: Lipomas are benign, slow-growing tumors frequently subcutaneous and asymptomatic, intramuscular lipoma constituting a rare subtype. However, a...

Posterior interosseous nerve entrapment by intramuscular lipoma arising from the supinator muscle - a case report

Published Online: Aug 13, 2021

Page range: 24 - 29

Accepted: Jul 06, 2021

DOI: https://doi.org/10.2478/rojost-2021-0005

Keywords
posterior interosseous nerve, entrapment, supinator muscle, intramuscular lipoma

© 2021 Omar Refai et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Posterior interosseous nerve entrapment by intramuscular lipoma arising from the supinator muscle - a case report

Published Online: Aug 13, 2021

Page range: 24 - 29

Accepted: Jul 06, 2021

DOI: https://doi.org/10.2478/rojost-2021-0005

Keywordsposterior interosseous nerve, entrapment, supinator muscle, intramuscular lipoma

© 2021 Omar Refai et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Keywords
posterior interosseous nerve, entrapment, supinator muscle, intramuscular lipoma