Lymphatics of the submandibular space: an anatomic, clinical, and pathologic study with applications to floor-of-mouth carcinoma.

The detection and management of submandibular metastases are fundamental to the treatment of oral carcinoma. Detailed investigation of submandibular lymphatic anatomy and subsite predilection for metastases, as well as a comprehensive method for submandibular space dissection, have been lacking. This thesis explores submandibular lymphatic anatomy through a review of the literature and cadaver dissections. A standardized lymph node nomenclature and submandibular dissection technique are proposed. Also presented is a report on 41 consecutive patients with floor-of-mouth squamous cell carcinoma who were prospectively evaluated and treated. Pretreatment clinical and computed tomography (CT) examinations revealed the detection of submandibular metastases to be more difficult than for the remainder of the neck and not improved by the routine use of CT scanning. Management of the neck was either with surgery, which included complete bilateral level I dissections, or at least 2-year follow-up when left untreated. Overall, 39% of patients manifested submandibular disease. The majority of submandibular metastases in this study measured 1 cm or less and most commonly involved the perivascular (primarily prevascular) nodes followed by the preglandular and, previously ill-defined, deep nodes. These findings are discussed with regard to the rationale for currently used neck dissections.