Female, 44 years old, with history of recurrent triple negative breast cancer with right pectoralis muscle tumor causing paresthesias and weakness of the right arm. Evaluate for extent of tumor involvement in the plexus and nearby supraclavicular and axillary disease. A large centrally necrotic tumor aggregate is evident within the right subpectoral axilla. This lesion measures up to 128 mm CC x 111 mm AP x 90 mm TV. The mass is contiguous with the chest wall and extends laterally almost to the humeral cortex but with no evidence of osseous invasion. Superiorly it extends just above the clavicle, and inferiorly it indents the breast prosthesis. Much smaller discontiguous tumor deposits are evident within the right supraclavicular fossa.The above lesion resides predominantly at the level of the cords and terminal branches of the right brachial plexus. The neural structures are displaced posteriorly by the mass but they do remain visible throughout which would argue against encasement.Multiple lung nodules and perihilar adenopathy are also seen.
A bulky necrotic right axillary mass is identified situated predominately at the level of the cords and terminal branches of the brachial plexus. The neural structures are displaced and potentially compressed by the lesion, but they do not appear to be encased.