Five out of 48 (10.4%) cases were negative. melanoma) recently emerged as a novel marker for the diagnosis of melanoma. The current work aimed to evaluate the sensitivity and specificity of PRAME for the diagnosis of melanoma metastases in cytological samples, compared to other melanocytic markers. (2) Methods: PRAME, S100, Melan-A, HMB45 and SOX10 were tested on cell block sections of 48 cases of melanoma metastases diagnosed from cytological samples, and 20 cases of reactive lymphadenopathy. (3) Results: S100 and SOX10 showed the highest sensitivity (100%), while the sensitivity of PRAME was 85.4%. PRAME, Melan-A, SOX10 and HMB45 showed a specificity of 100%, while the specificity of S100 was lower (85%), as it marked some histiocytes. (4) Conclusion: PRAME immunocytochemistry is highly specific for the diagnosis of melanoma metastasis from a cytological sample, but is less sensitive compared with other melanocytic markers. 0.05. The statistical analysis was carried out using IBM SPSS statistics V.20. 2.5. Ethical Consideration The present study was retrospectively conducted on archival biological samples. The cytological diagnoses and their histological confirmations had already been rendered in all cases. At the time of the FNAC procedure, written consent, including consent to use the diagnostic data for scientific purposes, had been obtained from each patient. Approval by the institutional ethics board was attained. 3. Results Our series included 48 cases of CM metastases diagnosed from cytological samples. The diagnosis was subsequently confirmed histologically in all cases. The metastases were in the 4-Aminobutyric acid lymph nodes in 44 (91.6%) cases, in subcutaneous tissues in 2 (4.2%) cases and in the lungs in 2 (4.2%) cases. PRAME was positive in 41 (85.4%) cases and negative in the remaining 7 (14.6%) cases. Strong positivity was observed in 38 out of 41 (92.7%) positive cases, and weak positivity was observed in the remaining 3 out of 41 (7.3%) positive cases. The sensitivity of PRAME ICC was 85.4%. S100 was positive in all 48 cases (100%). Strong positivity was observed in 43 out of 48 (89.6%) cases, moderate positivity was observed in 3 out of 48 (6.2%) cases, and weak positivity was observed in the remaining 2 (4.2%) cases. The sensitivity of S100 ICC was 100%. SOX10 was positive in all 48 cases (100%). Forty-six out of 48 (96%) cases showed strong positivity, 1 out of 48 (2%) cases showed moderate positivity, and the remaining 1 (2%) case showed weak positivity. The sensitivity of SOX10 was 100%. Melan-A was positive in 47 out of 48 (97.9%) cases. One out ZNF384 of 48 (2%) cases was negative. Strong positivity was observed in 23 out of 47 (48.9%) positive cases, moderate positivity in 18 out of 47 (38.3%) 4-Aminobutyric acid cases, and weak positivity in 6 (12.8%) cases. The sensitivity of Melan-A was 97.9%. HMB45 was positive in 43 out 4-Aminobutyric acid of 48 (89.6%) cases. Five out of 48 (10.4%) cases were negative. Twenty-seven out of 43 (62.8%) positive cases showed strong positivity, 11 out of 43 (25.6%) positive cases showed moderate positivity, and the remaining 5 (11.6%) positive cases showed weak positivity. The sensitivity of HMB45 was 89.6%. The statistical analysis demonstrated a significantly lower diagnostic performance of PRAME compared with S100 (= 0.0004) and SOX10 (= 0.00001). Our series also included 20 cases of reactive lymphadenopathy diagnosed from cytological samples, and subsequently confirmed histologically. In 4-Aminobutyric acid these cases, PRAME, SOX10, Melan-A and HMB45 were negative in 20 out of 20 cases (100%), while S100 marked histiocytes in 3 out of 20 (15%) cases, making the distinction between histiocytes and melanocytes difficult. The specificity of PRAME, SOX10, Melan-A and HMB45 was 100%, while the specificity of S100 was 85%. The results are summarized in Table 1 and Figure 1. Some examples of the ICC staining are showed in Figure 2. Open in a separate window Figure 1 Distribution of staining scores for the immunocytochemistry antibodies. Immunocytochemical stains for S100, Melan-A, SOX10, HMB45 and PRAME were performed in 48 cytological samples of melanoma metastases. S100 and SOX10 were positive in all cases (100%). Melan-A, HMB45 and PRAME were negative in 1 (2.1%), 5 (10.4%) and 7 (14.6%) cases, respectively. SOX10 showed.
