Intramuscular myxoma

Case contributed by Dr Utkarsh Kabra


Swelling in the lateral aspect of left arm.

Patient Data

Age: 35
Gender: Female


Well defined lesion within the intramuscular plane of distal deltoid muscle appearing homogeneously isointense on T1 and hyperintense on T2W / STIR images relative to the surrounding muscle. A subtle rim of fat is seen on T1 images.




Histopath shows oval and spindle shaped cells in a background of myxomatous tissue.

Case Discussion

Intramuscular myxomas are rare benign myxoid lesions, commonly seen in middle-aged women.

On imaging, they are often seen in the large muscles of the thighs, buttocks, or shoulder girdle, and present as well-defined cystic-like lesions with a surrounding rim of fat. They tend to occur in adults around 40 and 60 years with a recognized female predilection (70%). They are associated with fibrous dysplasia as part of Mazabraud syndrome. Our case shows a well-defined homogeneous mass appearing hyperintense on T2W / STIR images and isointense on T1W images relative to surrounding muscle, with a subtle rim of fat. Imaging features, location of the lesion, age group and sex lead to the diagnosis of intramuscular myxoma, which was later confirmed on FNAC.

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Case information

rID: 61180
Published: 30th Aug 2018
Last edited: 14th Aug 2019
Inclusion in quiz mode: Included
Institution: Getwell Poly Clinic & Hospital

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