A 51 y.o. woman presents with fever and L biceps pain

What do you see on her CT?

Hint follow the course of the intercostal brachial nerve

Thanks to Drs. Levine and Lew

Our patient had a mass in the chest wall compressing the intercostal brachial nerve. The nerve is a lateral cutaneous branch of the second intercostal nerve that supplies sensation to the skin of the axilla and upper arm.   It leaves the second intercostal space in the midaxillary line and pierces the serratus anterior muscle to enter the subcutaneous tissues of the axilla. It may  join with the medial cutaneous nerve of the arm to supply the medial arm.

the abscess ion the chest wall

The most common cause of this syndrome is breast surgery or radiation  where there is direct injury to the nerve.  This can cause severe pain in the arm and decrease quality of life.  It is estimated that 10-60% of breast cancer survivors  who have undergone operative procedures have persistent pain because of damage to the nerve.

The course of the nerve is extremely variable

In the case of our patient, the chest wall mass affecting the intercostal brachial nerve was an abscess which grew out Strep Pyogenes.  She was treated with vanc and cefe in the ED and switched to  ceftriaxone and eventually discharged on clindamycin. A biopsy done of a L chest wall lymph node showed no evidence of malignancy.

Henry B, Graves M, Pekala J, et al. Origin, branding and communications of the intercostobrachial nerve: a meta-analysis with implications for mastectomy and axillary lyph node dissection in breast cancer. 2017 CureusMar;((3) e1101 doi:10.7759/cureus.1101.

Kumar P, Meena R, Sheikh B, et al. Intercostobrachial nerve-anatomical considerations and its importance in carcinoma of the breast of femal patients. Ann Surg Perioper Care. 2016;1(2):1013.

Singh B. Complex regional pain syndrome of the breast and chest wall. Breast J.  2016;22(3):366-368.