Twelve years' experience of sentinel lymph node biopsy for melanoma at a rural New Zealand hospital.

AIM: To document the false-negative sentinel lymph node biopsy (SLNB) rate for melanoma patients at a rural NZ hospital and the likelihood of further nodal involvement on completion lymph node dissection (CLND). METHODS: All patients undergoing SLNB for melanoma at this centre were identified from the study period. Basic demographics along with histological data of both the primary lesion and SLNB were collated. Local and regional recurrences were recorded as was mortality. RESULTS: Between January 2000 and July 2012, 95 patients underwent SLNB for melanoma. Ten patients (11%) underwent CLND after positive SLNB. A further two patients had a median of two additional nodes involved (range 1-3). After a median follow-up period of 65 months (range 47-112), 6 patients suffered nodal recurrence where previously a negative SLNB had been harvested, giving a false-negative rate of 38%. Recurrence occurred a median of 16 months after WLE and SLNB. CONCLUSION: A high false negative-negative rate was observed in this study. For those with a positive SLNB, a further 20% have further nodal involvement on CLND.