Masaya Kawaguchi

Prediction of grading of ovarian endometrioid carcinoma using conventional MRI features

Abstract Objective The purpose of this study was to evaluate MRI findings of ovarian endometrioid carcinoma (OEC) as a predictor of histological grade. Materials and methods This study included 60 patients with histopathologically confirmed OEC (20, 30, and 10 with grades 1, 2, and 3, respectively). Clinical and MRI results were retrospectively reviewed. We compared the following parameters between the three grades: age, tumor markers, presence of uterine corpus cancer, bilaterality, configuration, peritoneal dissemination, abnormal ascites, signal intensities of cystic and solid components, tumor size, and apparent diffusion coefficient (ADC) values of solid components. Results T1-hyperintense cysts were more common in grade 1 than in grades 2–3 OEC (80% vs. 60%, vs. 40%, p < 0.05). The signal intensity ratio between the cystic components with the largest solid component and muscle (1.49 vs. 1.08 vs. 0.98, p < 0.05) was higher in grade 1 than in grades 2–3 OEC. Necrosis within solid components was less common in grade 1 than in grades 2–3 OEC (31% vs. 68% vs. 88%, p < 0.05), and the ADC values of solid components were higher in grade 1 than in grades 2–3 OEC (1.10 vs. 0.99 vs. 0.79 × 10−3 mm2/sec, p < 0.05). There were no significant differences in other factors. Conclusion On T1-weighted images, grade 1 OEC showed a higher signal intensity in the cystic components than grades 2–3 OEC. Necrosis and lower ADC values were more frequently observed in grades 2–3 than in grade 1 OEC.

MRI findings of malignant transformation arising from mature cystic teratoma of the ovary: comparison with benign mature cystic teratoma

Abstract Objective This study aimed to evaluate the efficacy of MRI findings to differentiate malignant transformation arising from mature cystic teratoma (MT-MCT) of the ovary from benign mature cystic teratoma (BMCT). Materials and methods This study included 11 patients with histopathologically proven MT-MCT and 50 with BMCT. Overall, 7 patients with MT-MCT and all 50 with BMCT underwent unenhanced and contrast-enhanced MRIs and 4 with MT-MCT only underwent unenhanced MRIs. The MRI findings were evaluated and compared between the two diseases. Results The median age (55 vs. 38 years, p < 0.01) and maximum diameter (109 vs. 65 mm, p < 0.01) were higher in MT-MCT than in BMCT. Fat component occupancy was lower in MT-MCT than in BMCT (median, 5% vs. 63%, p < 0.01). Only MT-MCT exhibited irregular tumor margins (64%), peritoneal dissemination (18%), and abnormal ascites (27%). The solid components were more commonly observed in MT-MCT than in BMCT (100% vs. 32%, p < 0.01) on contrast-enhanced images. The maximum diameter of solid components in MT-MCT was larger than that in BMCT (median, 61 mm vs. 14 mm, p < 0.01). In MT-MCT, the common configuration of solid components was endophytic or exophytic sessile (85%), whereas in BMCT, it was endophytic papillary (88%). Conclusion Compared with BMCT, MT-MCT demonstrated a larger maximum diameter, lower occupancy rate of fat components, and sessile solid components. The characteristic configuration of solid components was endophytic or exophytic sessile in MT-MCT and endophytic papillary in BMCT.

CT and MRI characteristics of ovarian mucinous tumors associated with mature teratomas

This study aimed to evaluate the CT and MRI features of ovarian mucinous tumors associated with mature teratomas. The present study enrolled a total of 34 patients with histopathologically proven ovarian mucinous tumors associated with mature teratomas, including collision tumors composed of mucinous tumors and mature teratomas and mucinous tumors arising from mature teratomas. All patients underwent preoperative pelvic CT and/or MRI. Imaging findings were retrospectively reviewed. Histopathological diagnosis of mucinous tumors included mucinous cystadenoma in 22 patients, mucinous borderline tumor (MBT) in 10 patients, and mucinous carcinoma in two patients. The mean maximum tumor diameter was 168 mm (range, 39-314 mm). All tumors were unilateral, well-defined, predominantly cystic, and multilocular. A total of 14 tumors (41 %) had fewer than 10 loculi, while 12 tumors (35 %) had 30 or more. Fatty components were observed in 30 tumors (88 %), and 20 of 30 tumors (67 %) had multiple fatty components. On MRI, stained glass appearance was observed in 20 of 29 tumors (69 %). On CT, nodular calcifications within fatty components were observed in 12 of 21 tumors (57 %), whereas flattened calcifications within the septa of non-fatty components were observed in 7 of 21 tumors (33 %). Pseudomyxoma peritonei (PMP) was observed in three patients (9 %) with MBT. Ovarian mucinous tumors associated with mature teratomas typically presented as large, multilocular cystic lesions with fatty components and teratoma/mucinous tumor-associated calcifications. Although PMP was uncommon, it was rarely observed in patients with MBT.

Can MRI features differentiate ovarian mucinous carcinoma from mucinous borderline tumor?

Our purpose was to determine if MRI could be used to distinguish ovarian mucinous carcinoma (MC) from mucinous borderline tumor (MBT). This study included 63 consecutive patients with histopathologically proven ovarian mucinous neoplasms (11 MCs and 52 MBTs) who underwent preoperative contrast-enhanced MRI. MRI images were retrospectively reviewed and compared between the 2 pathologies. The maximum tumor diameters (219.7 ± 80.8 mm vs. 177.4 ± 56.5 mm, p <  0.05) and maximum mural nodule (MN) diameters (41.7 ± 33.8 mm vs. 6.6 ± 8.9 mm, p <  0.01) were significantly larger in MCs than in MBTs. MNs larger than 5 mm (82 % vs. 29 %, p <  0.01) and abnormal ascites (45 % vs. 12 %, p <  0.05) were significantly more frequent in MCs than in MBTs. Apparent diffusion coefficient (ADC) values of MN were significantly lower in MCs than in MBTs (1.20 ± 0.25 × 10 MRI findings of these 2 pathologies overlapped considerably. Compared with MBTs, MCs exhibited larger tumor size, larger MN size, and lower ADC values of MN, and MCs more frequently had MNs larger than 5 mm and abnormal ascites. T2 hypointense microcysts might be a specific MRI finding in MBTs.

CT and MRI characteristics of ovarian mature teratoma in patients with anti-N-methyl-D-aspartate receptor encephalitis

The purpose of this study was to determine the computed tomography (CT) and magnetic resonance imaging (MRI) characteristics of ovarian mature teratoma in patients with anti-N-methyl-d-aspartate receptor encephalitis (NMDAR-E). A total of 125 women (mean age, 40.9±17.8 [SD] years; age range: 12-85 years) with 146 histopathologically or radiologically proven ovarian mature teratomas who underwent preoperative CT and MRI examinations were retrospectively included. Eight patients with 11 teratomas had NMDAR-E, whereas 117 patients with 135 teratomas did not have NMDAR-E. CT and MRI examinations were retrospectively reviewed and teratomas in patients with NMDAR-E were compared to those in patients without NMDAR-E. Comparisons were performed using Mann-Whitney U test or Fisher exact test. In patients with NMDAR-E, maximum diameter of teratomas (26.1±9.3 [SD] mm), prevalence of teeth/calcification (36%) and rate of occupation by fat components (26%) were lower than those in patients without NMDAR-E (67.0±37.6 [SD] mm [P<0.01]; 75% [P<0.05]; and 65%[P<0.01], respectively). More than 75% of space was occupied by fat components in 76/135 teratomas (56%) in patients without NMDAR-E, whereas this was not observed in any teratoma in patients without NMDAR-E. By comparison with teratomas in patients without NMDAR-E, teratomas in patients with NMDAR-E are smaller, have few teeth/calcification, and the amount of space occupied by fat components is smaller.

Uterine extension determined by MRI: a useful parameter for differentiating subserosal leiomyomas from ovarian tumors

This study aimed to evaluate the utility of uterine extension determined via MRI for the differentiation of large subserosal leiomyomas from ovarian tumors. In total, 55 patients with subserosal leiomyomas and 127 patients with ovarian tumors were included in this study. These patients were selected from a cohort of female patients whose pelvic masses were larger than 10 cm and who underwent preoperative MRI. We retrospectively reviewed the MRI and compared the diagnostic ability of uterine extension measurements and bridging vascular signs for differentiating subserosal leiomyomas from ovarian tumors. The vertical height of the uterus (107.2 ± 36.4 mm vs. 59.9 ± 24.9 mm, p  81 mm, were 0.89, 89%, and 80% and those of the uterine length, using cutoff threshold > 84 mm, were 0.85, 69%, and 93%, respectively. Alternatively, the sensitivity and specificity of bridging vascular sign were 78% and 94%, respectively. Uterine extension determined via MRI is a useful parameter for differentiating large subserosal leiomyomas from ovarian tumors.