Lymphatic mapping and sentinel lymph node biopsy in squamous cell carcinoma of the lower lip

The risk of metastases to the submandibular and submental lymph nodes in squamous cell carcinoma (SCC) of the lower lip is closely related to the primary tumour size and the differentiation of the tumour. In order to determine the feasibility of the technique and the possible metastatic lymph nodes in SCC of the lower lip, intraoperative lymphatic mapping and sentinel lymph node biopsy was performed in patients with tumour size greater than 2 cm (T2) and clinically non-palpable regional lymph nodes (N0).

Intraoperative lymphatic mapping with patent blue dye was performed in 20 patients with SCC of the lower lip. The stained lymph node (sentinel) was identified in each patient and sent for frozen section analysis in order to verify tumour metastasis. All patients had undergone bilateral suprahyoid neck dissection at the same stage.

Three of the patients were female and 17 were male. The median age was 66. Sentinel lymph nodes were identified in 18 of the patients (90%). Intraoperative or post-operative histopathologic examination of the sentinel lymph node showed tumour metastasis in three of the patients (16.6%). The histopathologic examination of the remaining 15 patients whose sentinel lymph nodes were free of metastasis, showed no metastasis in the non-sentinel lymph nodes. In two of the three patients with metastatic sentinel lymph nodes, non-sentinel lymph nodes were free of metastases. There were no false negative results and no local or systemic complications of the technique were seen among the patients.

Intraoperative lymphatic mapping and sentinel lymph node biopsy is feasible in patients with SCC of the lower lip who have large tumour size and non-palpable regional lymph nodes. The technique may help to avoid neck dissection when the patient has negative sentinel lymph node and when positive provides useful information for more effective radical treatment.