Lymphatic drainage to triangular intermuscular space lymph nodes in melanoma on the back.

METHODS: Lymphoscintigraphy with 99mTc-antimony sulphide colloid was performed on patients with cutaneous melanoma of the back to define draining node fields and sentinel nodes before surgery. RESULTS: One patient was found to have drainage from the back to sentinel lymph nodes in the triangular intermuscular spaces bilaterally, above and lateral to the scapula. Subsequently, drainage to this node field has been found in 26% of 42 consecutive patients who have had lymphoscintigraphy performed for melanoma on the back. CONCLUSION: When performing lymphoscintigraphy to locate draining node fields and sentinel nodes in patients with melanoma on the back, it is important to look for drainage to the triangular intermuscular space node field by obtaining posterior and lateral scans. Any sentinel lymph nodes found in this field should be marked prior to surgery in the same way as nodes in other node fields are delineated so that they may be removed at surgery.