MRI of endometriotic cysts in association with ovarian carcinoma.

OBJECTIVE: Although mural nodules are considered to be the most important hallmark in the recognition of ovarian cancers accompanied with endometriotic cysts, benign neoplasms and even inflammatory diseases can show similar MRI findings. We sought to clarify the MRI characteristics of malignancy accompanied with endometriotic cysts of the ovary. MATERIALS AND METHODS: Contrast-enhanced MRI was performed and endometriosis was pathologically confirmed in 49 patients with endometriotic cysts displaying mural nodules. Malignancy was pathologically diagnosed in 33 patients and benignity, in 16. Clinical data including patient age and MRI findings in terms of the size of the endometriotic cysts, number of loculi, presence of shading of the cysts, size of the mural nodules, signal intensity of the mural nodules on T1- and T2-weighted images, and contrast enhancement of the mural nodules were retrospectively reviewed. Statistical analysis of each parameter used the Mann-Whitney U test. RESULTS: The mean age of the patients and mean size of the endometriotic cysts were significantly higher in patients with a malignant condition than in those with a benign condition. Contrast enhancement of the mural nodules was observed in 97% of malignant and 44% of benign tumors. The size of the mural nodules was significantly larger in patients with a malignant condition than in those with a benign condition. Differences in size between the bilateral diseases, multilocularity, existence of shading, and the signal intensities of mural nodules were not significantly different between the malignant and benign conditions. CONCLUSION: Endometriotic cysts with enhanced mural nodules are not always complicated with malignancy. In elderly patients, the presence of large enhanced nodules on large endometriotic cysts is more likely to indicate malignancy.

MR findings of ovarian tumors with hormonal activity, with emphasis on tumors other than sex cord-stromal tumors.

Sex cord-stromal tumors including granulosa cell tumor, thecoma, Sertoli stromal cell tumor and steroid cell tumor are noted for their hormonal activity. However, there are many kinds of ovarian tumors other than sex cord-stromal tumors and tumor-like conditions with endocrine manifestations. Cross-sectional imaging, especially MR, can provide precise features of ovarian tumors and uterine morphological change even in a clinically latent excess of estrogen. In this article, we demonstrate typical imaging findings of ovarian tumors with hormonal activity. We also shortly explain the mechanism of the virilization and hyperestrogenism caused by ovarian tumors and tumor-like conditions.

Studies on neurosteroids XVI. Levels of pregnenolone sulfate in rat brains determined by enzyme-linked immunosorbent assay not requiring solvolysis.

Pregnenolone sulfate (PREGS) is reported to be present in higher concentration in the brain (more than 5 ng/g tissue in the rat) than in blood and is considered to be a neurosteroid. However, there are some doubts on its brain levels, because they were determined by indirect methods (e.g., GC-MS or radioimmunoassay after solvolysis). In the present study, PREGS in rat brains was determined by an enzyme-linked immunosorbent assay, which did not require solvolysis, after pretreatment with an Oasis HLB cartridge. The absolute recovery rate of PREGS through the pretreatment was 60.8%, and the quantitation limit was 33 pg/g tissue for a 200-mg of brain aliquot. Intra- and inter-assay coefficients of variation were less than 15.1 and 9.2%, respectively. The brain PREGS levels in the control rats (n=10) were less than 0.15 ng/g tissue except for one sample (0.42 ng/g tissue) and were lower than the serum levels (n=5, 0.25-0.47 ng/ml). On the contrary, the brain PREGS levels were sufficiently increased after intrapertioneal injection of 2 mg/kg body of PREGS (n=5, 0.37-1.29 ng/g tissue). These results demonstrate that, in rats, the brain PREGS may be derived from peripheral sources, and its actual levels are much lower than those previously measured by indirect methods.

Studies on neurosteroids XV. Development of enzyme-linked immunosorbent assay for examining whether pregnenolone sulfate is a veritable neurosteroid.

An enzyme-linked immunosorbent assay (ELISA) of pregnenolone sulfate (PREGS) has been developed for examining whether it is a veritable neurosteroid. 11alpha-Hemiglutaryloxy-PREGS was newly synthesized and conjugated with bovine serum albumin (BSA), which was injected to rabbits for the production of anti-PREGS antibodies. A bridge-heterologous ELISA system employing the sequential saturation method exhibited a high sensitivity with a midpoint of 30 pg. Although the antibody showed some cross-reactivity with PREG (4.4%), it easily discriminated other related steroids reported to exist in the mammalian brain. The rat brain homogenate was treated with hexane and subjected to an OASIS HLB cartridge, which was washed with AcOEt to remove the unconjugated steroids, and then the desired sulfate was eluted with EtOH. The recovery rate of PREGS through the pretreatment was satisfactory, but its brain levels in the preliminary experiments were much lower than those previously measured by gas chromatography (GC)-mass spectrometry (MS) after solvolysis. These results practically agreed with our previous results by liquid chromatography (LC)-electrospray ionization (ESI)-MS without deconjugation.