Clear cell odontogenic carcinoma (CCOC) is a rare malignant tumor. To date, only 67 cases were described in the English literature and complete understanding of the behavior of CCOC was based on limited case reports. In this article, we reported 6 additional cases and reviewed the relevant literature. Our cases included 4 men and 2 women with an average age of 52.8 years. The tumors were all in the mandible and presented as poorly marginated radiolucencies. Patients were treated with resection. All cases consisted of islands and sheets of clear cells that were separated by fibrous septa. Immunohistochemically, the tumor cells were positive for pan-cytokeratins, CK14, CK19, and epithelial membrane antigen, but negative for S-100 protein, smooth muscle actin, desmin, human melanoma antigen, CD3, CD45, and glial fibrillary acidic protein. A series of literature review disclosed the tumor has a female preponderance (44 female vs. 23 male, 1.9:1). The mean age was 54.5 years and the predominant site was the mandible (51, 76.1%). Forty-seven (70.1%) patients were initially treated with surgical resection, 15 (22.4%) patients underwent curettage or enucleation, and 1 patient was treated with chemotherapy. Nine patients had a neck dissection in addition to a surgical resection. Seven (9.6%) patients received postoperative radiotherapy. The recurrence rate after resection was lower than conservative therapy (29 vs. 86.7%). Nine patients died of the tumor. CCOC is a potentially aggressive lesion and owing to a high recurrent rate of conservative measure; therefore, radical surgical treatment is recommended and long-term follow-up is necessary.

Introduction: Fast screening tests for hepatitis C virus (HCV) antibody often give false-positive results. Signal-to-cut-off (S/Co) ratios were suggested to be used as reflex confirmation of anti-HCV. The Elecsys Anti-HCV II assay is an effective test for the detection of hepatitis C, but no S/Co cutoff has been reported. The aim of this study was to determine the S/Co ratio threshold of anti-HCV test using Elecsys Anti-HCV II screening and supplemental recombinant immunoblot assay (RIBA) test results as the gold standard. Methodology: A total of 36,341 serum samples were tested for HCV antibody using the Elecsys Anti-HCV II assay and 276 positive samples were then tested with supplemental RIBA (Mikrogen recomLine HCV IgG strip immunoassay). Receiver operation curve (ROC) analysis was used to determine the cutoff, sensitivity, and specificity of the optimal S/Co ratio. Results: The Elecsys Anti-HCV II assay was positive (S/Co ratio ≥ 1) in 288 of the 36,341 samples (0.79%). RIBA testing on 276 of these 288 positive samples showed that all but one of 44 samples with an S/Co ratio of ≥ 1 and < 10 were negative, whereas the vast majority of samples (223/232, 96.1%) with an S/Co ratio ≥ 10 were positive. ROC analysis revealed that an optimal S/Co ratio cut-off value was 12.27. Conclusions: An S/Co ratio of 12.27 obtained with the Elecsys Anti-HCV II assay could be used as reflex confirmation of anti-HCV tests.