The triangular intermuscular space as a site of lymph node metastasis in melanoma of the back.

The Triangular Intermuscular Space is defined by borders of the teres major, teres minor, and long head of the triceps. Through this space pass the descending circumflex scapular artery, vena comitants, and lymphatics. We report 3 patients with truncal melanoma, presenting with recurrent disease in the TIS. These cases suggest that in patients with melanoma of the back, the Triangular Intermuscular Space, as the gateway to the axilla, may be an important site of metastatic disease.