title: Endometrioid adenocarcinoma of the ovary: MRI findings with emphasis on diffusion-weighted imaging for the differentiation of ovarian tumors.
abstract: BACKGROUND
  Preoperative differentiation of ovarian malignant tumors still remains a challenge. Diffusion-weighted imaging (DWI) provides information about cellularity of the lesion and might facilitate discrimination between different malignant ovarian lesions.
  
  
  OBJECTIVE
  To evaluate magnetic resonance imaging (MRI) findings of endometrioid adenocarcinoma of the ovary and to determine the value of DWI in the differential diagnosis of malignant and benign adnexal tumors.
  
  
  METHODS
  The following MRI findings were reviewed in 162 patients (21 endometrioid adenocarcinoma, 103 other malignant tumors, 38 benign tumors): lesion size, morphological appearance, T2-weighted (T2W) signal intensity, T1-weighted (T1W) signal intensity, contrast-enhancement pattern, DWI signals with apparent diffusion coefficient (ADC) calculated for b = 800 s/mm(2) in solid tumor components.
  
  
  RESULTS
  The most common morphological appearance was predominantly cystic lesion, found in 90.3% of patients with endometriod adenocarcinoma. The solid parts were slightly hyperintense on T2W images in 19 patients with marked enhancement after contrast administration. No significant difference (P = 0.13) in conventional MRI features was found between endometrioid adenocarcinoma and other malignant ovarian tumors. Hyperintensity on DWI was more frequently observed in malignant tumors than in benign lesions (P < 0.001). ADC values were significantly lower in endometrioid adenocarcinoma than other malignant tumors (0.79 ± 0.21 vs. 0.90 ± 0.19; P = 0.04) and in all malignant lesions compared with benign tumors (0.88 ± 0.31 vs. 1.33 ± 0.17; P < 0.001).
  
  
  CONCLUSIONS
  DWI with ADC measurement could indicate the presence of endometrioid adenocarcinomas due to a slightly but significantly lower ADC values compared to other malignant ovarian lesions. Thus, DWI is beneficial and should be part of a standard protocol for the evaluation of indeterminate adnexal lesions.
authors: Center for Radiology and Magnetic Resonance Imaging, Clinical Center of Serbia, Faculty of Medicine, University of Belgrade, Belgrade, Serbia jelenadjokic2003@yahoo.co.uk.
authors: Jelena Djokić
authors: JD
authors: Kovač
authors: Clinic for Gynecology and Obstetrics, Clinical Center of Serbia, Faculty of Medicine, University of Belgrade, Belgrade, Serbia.
authors: Milan
authors: M
authors: Terzić
authors: Center for Radiology and Magnetic Resonance Imaging, Clinical Center of Serbia, Faculty of Medicine, University of Belgrade, Belgrade, Serbia.
authors: Milan
authors: M
authors: Mirković
authors: Center for Radiology and Magnetic Resonance Imaging, Clinical Center of Serbia, Faculty of Medicine, University of Belgrade, Belgrade, Serbia.
authors: Bojan
authors: B
authors: Banko
authors: Pathology Department, First Surgical Clinic, Clinical Center of Serbia, Belgrade, Serbia.
authors: Aleksandra
authors: A
authors: Đikić-Rom
authors: Center for Radiology and Magnetic Resonance Imaging, Clinical Center of Serbia, Faculty of Medicine, University of Belgrade, Belgrade, Serbia.
authors: Ružica
authors: R
authors: Maksimović
mesh_terms: D000368:Aged; D018269:Carcinoma, Endometrioid / Q000000981:diagnostic imaging*; D003287:Contrast Media; D003937:Diagnosis, Differential; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D016889:Endometrial Neoplasms / Q000000981:diagnostic imaging*; D005260:Female; D019786:Gadolinium DTPA; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D008875:Middle Aged; D010051:Ovarian Neoplasms / Q000000981:diagnostic imaging*; D012189:Retrospective Studies; D012680:Sensitivity and Specificity
chemical_list: D003287:Contrast Media; D019786:Gadolinium DTPA
keywords: Endometrioid adenocarcinoma; diffusion-weighted imaging (DWI); magnetic resonance imaging (MRI); ovarian tumors