Pectoral muscle sarcoma masquerading as breast lump

Case contributed by Dr Chris O'Donnell


Non painful, fixed right breat lump for investigation. Negative mammogram.

Patient Data

Age: 40 years
Gender: Female

MRI breast scan performed to investigate mammogram negative breast lump

Well-defined mass in the right pectoralis muscle deep to the breast tissue showing the rapid, washout enhancement seen in malignant lesions. B-value of 1000 showing restricted diffusion.


Ultrasound performed for the purposes of biopsy

Well-defined hypoechoic mass in the pectoralis muscle. It was biopsed after careful consideration of surgical planning in consultation with the surgeon.

Case Discussion

Well-defined mass with washout enhancement and restricted diffusion in the pectoralis muscle, not the breast parenchyma.  Biopsy suggests a low-grade sarcomatous lesion with associated chronic inflammation.

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Case information

rID: 31524
Published: 19th Dec 2014
Last edited: 15th Sep 2019
Inclusion in quiz mode: Excluded

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