Sentinel Node Biopsy in Cutaneous Squamous Cell Carcinoma.

Objective: In cases of cutaneous squamous cell carcinoma (SCCa), early detection of regional metastases can greatly improve survival. The objective of this study is to explore the utility of sentinel lymph node biopsy (SLNB) for early detection of regional metastasis in patients with high-risk cutaneous SCCa of the head and neck. Method: Participants include patients with cutaneous SCCa of the head and neck with high-risk prognostic features (size >2 cm, recurrence, depth >4-5 mm, poor differentiation, perineural invasion, history of CLL/SLL/organ transplantation) but no nodal metastases. All patients underwent excision of the primary tumor with SLNB. Specimens were analyzed for evidence of regional metastases. Results: Preliminary results include 19 patients who underwent excision of their tumor with SLNB, and 5 of 19 (26%) of these high-risk patients developed regionally metastatic disease. SLNB demonstrated a sensitivity of 80%. There was a SLNB false omission rate of 20%. Of the 5 patients with regional metastases, 1 (20%) demonstrated perineural invasion, 3 (60%) demonstrated lymphatic invasion, 3 (60%) demonstrated vascular invasion, 4 (80%) demonstrated poor differentiation, and all 5 (100%) demonstrated depth >4 mm. One case of false omission occurred in a patient with CLL. All patients are currently living, and 2 (40%) have developed regional recurrence. Conclusion: SLNB is capable of identifying early regional metastases in cutaneous SCCa. Preliminary data demonstrate that 26% of high-risk patients developed regional metastases. SLNB effectively identified 80% of metastatic disease, with a 20% false omission rate. Regional metastasis was most strongly associated with lymphovascular invasion, poor differentiation, and depth >4 mm.