The role of ThinPrep cytology in the investigation of SLN status in patients with cutaneous melanoma

Introduction: The sentinel lymph node (SLN) biopsy in melanoma assesses reliably the status of the regional lymph node basins, provides valuable prognostic information, facilitates early therapeutic lymphadenectomy and identifies patients who are candidates for different adjuvant treatments. The current study was designed to evaluate the feasibility of cytological specimens being placed in PreservCyt^® as a practical collection methodology for performing evaluation of the SLN status in patients with melanomas. Patients and methods: From January 2004 to December 2006, 70 patients with histologically confirmed cutaneous melanoma underwent intraoperative FNA biopsy of the SLN. After identification of the SLN(s), FNA biopsy of the SLN was performed with a 0.6 mm (23 gauge) diameter needle. All the SLNs specimens were examined (using light microscopy 40× and 200×) by the same pathologist and cytopathologist, neither of had any knowledge of the medical history of the patient. The histological result of the excised SLN was considered as the final diagnosis. Results: The unsatisfactory rate for TP cytology was 2.17%. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and overall accuracy (OA) for the TP technique were 92.31%, 100%, 100%, 97.06%, and 97.83%, respectively. Using TP cytology, there was greater intensity and distribution of the staining in comparison with immunohistochemistry. Discussion: The accuracy of TP technique in the evaluation of the SLN status is comparable to those of the histological evaluation, and could be of paramount importance for the preoperative planning of treatment.