Elevated preoperative neutrophil : lymphocyte ratio as a preoperative indicator of mature cystic teratoma with malignant transformation

AIM: To examine the usefulness of the neutrophil : lymphocyte (N/L) ratio as a cost‐effective and simple diagnostic marker of mature cystic teratoma (MCT) with malignant transformation (MT). METHODS: A retrospective chart review was performed between 1998 and 2013 of 12 MCT patients with MT and between 2009 and 2013 of 130 patients with benign MCT. Data were collected on age, tumor size, white blood cell count with differential counts, tumor marker levels, and presenting features. RESULTS: Older age, greater tumor size, higher CA19‐9 or CA125, higher neutrophil count, and higher N/L ratio were associated with MT on univariate analysis. White blood cell count; lymphocyte count; and the tumor marker squamous cell carcinoma antigen were not associated with MT. Older age (≥median), larger tumor size (≥10 cm), and high N/L ratio (≥5.0) were predictors of MT (hazard ratio, 11.51, 5.87, and 11.11, respectively). Six of 12 patients were diagnosed with MT on preoperative magnetic resonance imaging and five of 12 had an N/L ratio ≥5.0. CONCLUSIONS: Neutrophil : lymphocyte ratio is a potential preoperative diagnostic marker of MT. The optimal cut‐off should be determined in future large‐scale studies.