To investigate the computed tomography (CT) and magnetic resonance imaging (MRI) characteristics of ovarian serous borderline tumors (SBTs), and evaluate whether CT and MRI can be used to distinguish micropapillary from typical subtypes.
We retrospectively reviewed the clinical features and CT and MR imaging findings of 47 patients with SBTs encountered at our institute from September 2013 to December 2019. 30 patients with 58 histologically proven typical SBT and 17 patients with 26 micropapillary SBT were reviewed. Preoperative CT and MR images were evaluated, by two observers in consensus for the laterality, maximum diameter (MD), morphology patterns, internal architecture, attenuation or signal intensity, ADC value, enhancement patterns of solid portions (SP), and extra-ovarian imaging features.
The median age were similar between typical SBT and SBT-MP (32.5 years, 36 years, respectively, P>0.05). Morphology patterns between two subtypes were significantly different on CT and MR images (P < 0.001). Irregular solid tumor (21/37, 56.76%) was the major morphology pattern of typical SBT tumor, while unilocular cyst with mural nodules (14/20, 70%) was the major morphology pattern of SBT-MP on CT images. Similarly, papillary architecture with internal branching (PA&IB) (17/21, 80.95%) was the major morphology pattern of typical SBT tumor, while unilocular cyst with mural nodules (4/6, 66.67%) was the major pattern of SBT-MP on MR images. PA&IB all showed slightly hyperintense papillary architecture with hypointense internal branching on T2-weighted MRI. More calcifications were found in typical SBT (24/37, 64.86%) than SBT-MP mass lesion (6/20, 30%) (P < 0.05). Hemorrhage was less frequently visible in (20/37, 54.05%) typical SBT lessons than SBT-MP mass lesion (18/20, 90%) (P < 0.05). The ovarian preservation is more seen in typical SBT (38/58, 65.52%) than SBT-MP (12/28, 42.86%) in our series (P < 0.05). Mean ADC value of solid portions (papillary architecture and mural nodules) was 1.68 (range from 1.44 to 1.85) × 10-3 mm2/s for typical SBT and 1.62 (range from 1.45 to 1.7) × 10-3 mm2/s for that of SBT-MP. The solid components of the two SBT subtypes showed wash-in appearance enhancements after contrast injection both in CT and MR images except 2 of SBT-MP with no enhancement as complete focal hemorrhage on MR images.
Morphology and internal architecture are two major imaging features that can help to distinguish between SBT-MP and typical SBT.

BACKGROUND: Patients with 46, XY disorder of sex development (DSD) are predisposed to the development of gonadal tumors, particularly germ cell tumors and gonadoblastoma. However, to the best of our knowledge, there are no publications in the existing literature that refer to the coexistence of 46, XY DSD and serous tumors in the ovary.
METHODS: Here, we report the case of a 23-year-old female (social gender) patient with 46, XY DSD presenting with primary amenorrhea. Imageology revealed a huge mass in the left adnexa. Subsequent pathological analysis revealed a serous borderline tumor of the ovary.
CONCLUSIONS: Gonadal tumors of patients with 46, XY DSD are not necessarily malignant tumors and can coexist with borderline tumors with primitive corded gonads. The coexistence of DSD and serous borderline tumors is rare. Clearly, an early and accurate diagnosis plays an important role in the treatment of these patients. Although there may not be a clear correlation between the two lesions, it is vital that we specifically analyze the mechanisms involved so that we can determine whether patients with DSD are associated with an increase of developing serous borderline tumors of the gonad.

We report a case of complete androgen insensitivity syndrome (CAIS) accompanied by serous borderline tumors in a 75-year-old patient. Müllerian epithelial tumors are extremely rare condition in CAIS patients with only a few case reports. We report a case of late-diagnosed testicular feminization with hamartomas, and the first report of serous tumor with borderline malignant potential in such cases.

Serous borderline ovarian tumors (SBOTs) behave between benign cystadenomas and carcinomas, and the effective detection and clinical management of SBOTs remain clinical challenges. Because it is difficult to isolate and enrich borderline tumor cells, a borderline animal model is in need. 7,12-dimethylbenz[a]anthracene (DMBA) is capable of inducing the initiation, promotion, and progression of serous ovarian tumors. This study aims to investigate the proper dosage and induction time of DMBA for rat models of SBOTs, and explore their morphological features demonstrated by magnetic resonance (MR) imaging and molecular genetic characteristics. Rats were randomly divided into six groups (1 mg/70 D, 2 mg/70 D, 3 mg/70 D, 2 mg/50 D, 2 mg/90 D, and 2 mg/110 D). The 3 mg/70 D group induced the most SBOTs (50.0%, 12/24). The micropapillary projections were shown on MR imaging, which was the characteristic of SBOTs. The Cyclin D1 characterizing an early pathogenetic event strongly expressed in induced serous benign tumors (SBTs). The immunoreactivity staining scores of P53 expression significantly increased from SBTs, SBOTs to serous ovarian carcinomas (SCAs), which elucidate that P53 might be a promising biomarker to grade serous ovarian tumors. Based on morphological and molecular genetic similarities, this rodent SBOT model was suitable for investigating the pathogenesis of serous ovarian tumors and developing an early detection strategy.

The cell of origin of ovarian low-grade serous carcinoma (LGSC) remains unclarified. Our recent morphologic and immunophenotypic study suggests that most LGSCs may be derived from the fallopian tube. The purpose of the current study was to gain further insight into the origin of LGSC at the molecular level.
RNA-seq analysis was performed on a total of 31 tissue samples including LGSC (n=6), serous borderline tumors (SBT, n=6), fallopian tube epithelia (FTE, n=5), ovarian surface epithelia (OSE, n=4), and human peritoneal mesothelia (HPM, n=4). HGSC cases (n=6) served as a positive control. Gene expression profiles were compared and analyzed. To validate the findings from the gene expression array study, we selected the highly differentially expressed genes (PAX8, CDH1, FOXA2, and ARX) as well as those corresponding proteins and examined their expression levels in tissue samples of ovarian serous tumors, fallopian tube, ovarian surface epithelia, and peritoneal mesothelia.
Dendrograms revealed that OSE samples clustered with HPM, while ovarian serous tumors, including LGSC, SBT and high-grade serous carcinoma (HGSC), clustered with FTE. Furthermore, LGSC showed a significantly closer relationship with FTE than with OSE and HPM samples. PAX8, CDH1, and FOXA2 were highly and specifically expressed in serous tumors and FTE samples but not in OSE samples. In contrast, ARX was mainly expressed in OSE samples but not in FTE and serous tumors.
The findings of the current study provide further evidence at a molecular level that the fallopian tube is likely the cellular source of LGSC. This finding may enable new prevention strategies, improve early detection, and allow novel therapies to be tested.