Fig. 15.

A 43-year-old female presents with a stable left axillary mass for 3–4 years, which the patient reports to fluctuate with her menstrual cycle. MLO and CC views reveal no focal mammographic abnormality (not shown here). b Ultrasound demonstrated a complex oval mass with cystic and solid components lying within the muscle. Colour Doppler analysis demonstrates some peripheral blood flow. c Axial STIR and d axial post-gadolinium sequences demonstrate an ovoid lesion within the latissmus dorsi muscle at the level of the axilla, which was hypointense to muscle on T1-weighted images (not shown here) and shows increased signal intensity on the fluid-sensitive STIR sequence shown here. Post-gadolinium imaging shows some internal enhancement. CT-guided needle biopsy was performed. Final diagnosis: intramuscular myxoma of the latissimus dorsi