Lymphoscintigraphic drainage patterns of the auricle in healthy subjects

Abstract

In lymphoscintigraphies of the head and neck, multiple injections around a tumor result in variable drainage to multiple nodal basins. We undertook this study in healthy subjects to test whether single injections at specified points in the auricle display single predictable pathways and predict visualization of parotid sentinel lymph nodes (SLNs). Twenty-five healthy subjects were classified according to their injection points in the auricle. Each was injected bilaterally with 99mTc nanocolloid. Parotid and extraparotid lymph nodes were topographically differentiated. The procedure was repeated 1 week later. Lymphoscintigraphy was reproducible. Each injection revealed a single SLN. Injection site predicted parotid SLN visualization. Two lymphatic territories with parotid or extraparotid drainage were identified. Lymphatic territories in the auricle coincide with the vascular territories and branchial origins. Our findings contradict the notion that lymphatic drainage of the head and neck is unpredictable and variably involves multiple nodal basins.