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Henoch-Schonlein Purpura
Joseph Junewick, MD FACR
over 7 years ago
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Extensor Digitorum Brevis Manus

Case Detail

Anatomy: Musculoskeletal
Joseph Junewick, MD FACR
Diagnostic Category: Normal variant
Created: over 9 years ago
Updated: over 9 years ago
Tags: PEDS
Modality/Study Types: MR
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Teenager with pain and palpable lesion.

Case Images


Extensor Digitorum Brevis Manus


MR – Fusiform lesion isointense to muscle over the posterior carpus. Imaging of the contralateral wrist does not demonstrate similar lesion.


The extensor digitorum brevis manus is an uncommon accessory muscle of the dorsum of the hand found in approximately 1.6% of limbs. The extensor digitorum brevis manus can be unilateral or bilateral. It commonly originates from the dorsal wrist capsule deep to the extensor retinaculum but can also arise from the distal radius and deep carpal fascia and inserts into the index or middle digits. Extensor digitorum brevis manus are often misdiagnosed as ganglions, synovitis, giant cell tumor or carpal bosses since these are most conspicuous with the fingers extended. Typically the extensor digitorum brevis manus is painless. On MR, extensor digitorum brevis manus is a mass-like lesion with low T1 and T2 signal. Extensor retinaculum release or muscle excision is employed if symptomatic.


Sookur PA, Naraghi AM, Bleakney RR, et al. Accessory muscles: Anatomy, symptoms, and radiologic evaluation. Radiographics 2008; 28:481-499.


Ellen J. Junewick

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