title: Can ratio of the biggest tumor diameter to total tumor diameter be a new parameter in the differential diagnosis of agressive and favorable multifocal papillary thyroid microcarcinoma?
abstract: In this study, we aimed to evaluate the usefulness of a new parameter -ratio of the biggest tumor diameter to total tumor diameter- for the differentiation of agressive and favorable papillary thyroid microcarcinomas (PTMC).
  
  
  
  The diameter of the biggest tumor focus was taken as the primary tumor diameter. Total tumor diameter was calculated as the sum of the maximal diameter of each lesion. Ratio of primary tumor diameter to total tumor diameter was defined as tumor diameter ratio (TDR). Positive and negative predictive value, sensitivity and specificity of TDR to predict capsular invasion, extrathyroidal extension (ETE) and lymph node metastasis (LNM) were determined.
  
  
  
  Mean TDR was significantly lower in multifocal PTMC patients with capsular invasion, ETE, lymphovascular invasion and LNM compared to patients without these features. The sensitivities of TDR for the detection of LNM, ETE and capsular invasion were 100%, 100% and 94.2%, respectively. Specificity of TDR was 86.2% for LNM, 88% for ETE and 94.7% for capsular invasion. Best cut off values of TDR that can predict capsular invasion, ETE and LNM in multifocal PTMC were 0.62, 0.57 and 0.56, respectively. Multifocal papillary thyroid carcinoma patients with capsular invasion, ETE and LNM had significantly lower mean TDR when compared to ones without these features.
  
  
  
  Decreased TDR was associated with capsular invasion, ETE and LNM in patients with multifocal PTMC and PTC. This new parameter might be particularly helpful for the detection of aggressive behavior in multifocal PTMCs.
authors.affiliation: Yıldırım Beyazıt University Faculty of Medicine, Department of Endocrinology and Metabolism, Ankara, Turkey. Electronic address: endoali@hotmail.com.
authors.forename: Abbas Ali
authors.initials: AA
authors.lastname: Tam
authors.affiliation: Yıldırım Beyazıt University Faculty of Medicine, Department of Endocrinology and Metabolism, Ankara, Turkey.
authors.forename: Didem
authors.initials: D
authors.lastname: Özdemir
authors.affiliation: Yıldırım Beyazıt University Faculty of Medicine, Department of Endocrinology and Metabolism, Ankara, Turkey.
authors.forename: Neslihan
authors.initials: N
authors.lastname: Çuhacı
authors.affiliation: Yıldırım Beyazıt University Faculty of Medicine, Department of Endocrinology and Metabolism, Ankara, Turkey.
authors.forename: Hüsniye
authors.initials: H
authors.lastname: Başer
authors.affiliation: Yıldırım Beyazıt University Faculty of Medicine, Department of Endocrinology and Metabolism, Ankara, Turkey.
authors.forename: Ahmet
authors.initials: A
authors.lastname: Dirikoç
authors.affiliation: Yıldırım Beyazıt University Faculty of Medicine, Department of Endocrinology and Metabolism, Ankara, Turkey.
authors.forename: Cevdet
authors.initials: C
authors.lastname: Aydın
authors.affiliation: Ataturk Training and Research Hospital, Department of Pathology, Ankara, Turkey.
authors.forename: Aylin Kılıç
authors.initials: AK
authors.lastname: Yazgan
authors.affiliation: Yıldırım Beyazıt University Faculty of Medicine, Department of Endocrinology and Metabolism, Ankara, Turkey.
authors.forename: Reyhan
authors.initials: R
authors.lastname: Ersoy
authors.affiliation: Yıldırım Beyazıt University Faculty of Medicine, Department of Endocrinology and Metabolism, Ankara, Turkey.
authors.forename: Bekir
authors.initials: B
authors.lastname: Çakır
mesh_terms: D000328:Adult; D002291:Carcinoma, Papillary / Q000175:diagnosis* / Q000473:pathology; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D013964:Thyroid Neoplasms / Q000175:diagnosis* / Q000473:pathology
keywords: Aggressive behavior; Multifocality; Papillary thyroid microcarcinoma; Primary tumor diameter; Total tumor diameter; Tumor diameter ratio