Cystic endometrium on ultrasound scan: Sonographic-hysteroscopic-pathologic correlation.

OBJECTIVE: To assess the correlation between ultrasound findings of cystic endometrium and hysteroscopic and histopathologic findings. METHODS: A retrospective study was performed across two London hospital sites between January and December 2020. RESULTS: The percentage chance of having either endometrial hyperplasia or cancer was lower in our cohort of women with postmenopausal bleeding and ultrasound findings of cystic endometrium, compared with population estimates for women with postmenopausal bleeding alone (4.1% vs 10%-15% for endometrial cancer and 1.4% vs 5%-10% for endometrial hyperplasia). Conversely, a higher proportion of women in our cohort were diagnosed with endometrial polyps compared with population estimates for postmenopausal bleeding (68% vs 2%-12%). The rate of endometrial hyperplasia was significantly higher in our cohort of premenopausal women with abnormal uterine bleeding and cystic endometrium compared with population estimates for premenopausal patients with abnormal uterine bleeding (15.4% vs 1.4%). CONCLUSION: Cystic endometrium appears to be a powerful predictor of endometrial pathology. The high rate of endometrial hyperplasia in premenopausal women with cystic endometrium would advocate the need to obtain histologic diagnoses. Further studies are required to confirm whether cystic endometrium in women with postmenopausal bleeding confers a lower risk of endometrial hyperplasia and cancer.

Genetic identification of nascent peptides that induce ribosome stalling.

Several nascent peptides stall ribosomes during their own translation in both prokaryotes and eukaryotes. Leader peptides that induce stalling can regulate downstream gene expression. Interestingly, stalling peptides show little sequence similarity and interact with the ribosome through distinct mechanisms. To explore the scope of regulation by stalling peptides and to better understand the mechanism of stalling, we identified and characterized new examples from random libraries. We created a genetic selection that ties the life of Escherichia coli cells to stalling at a specific site. This selection relies on the natural bacterial system that rescues arrested ribosomes. We altered transfer-messenger RNA, a key component of this rescue system, to direct the completion of a necessary protein if and only if stalling occurs. We identified three classes of stalling peptides: C-terminal Pro residues, SecM-like peptides, and the novel stalling sequence FXXYXIWPP. Like the leader peptides SecM and TnaC, the FXXYXIWPP peptide induces stalling efficiently by inhibiting peptidyl transfer. The nascent peptide exit tunnel and peptidyltransferase center are implicated in this stalling event, although mutations in the ribosome affect stalling on SecM and FXXYXIWPP differently. We conclude that ribosome stalling can be caused by numerous sequences and is more common than previously believed.

Gastrointestinal stromal tumor in ascitic fluid. A case report.

BACKGROUND: There are few published data on the cytologic features of gastrointestinal stromal tumors (GISTs) in ascitic fluid and whether these features may mimic those of other malignancies. CASE: An 80-year-old woman presented with ascitics associated with multiple intraperitoneal masses. Cytologic examination of the ascitic fluid showed numerous three-dimensional clusters of epithelioid cells. These features and the presence of large, intracytoplasmic vacuoles raised a possible diagnosis of adenocarcinoma. However, mucin could not be demonstrated in the vacuoles, and the cells showed immunoreactivity for vimentin and c-kit but not for cytokeratins. Eighteen months earlier the patient had undergone a partial gastrectomy for a GIST, which predominantly comprised vacuolated, epithelioid cells. The immunoprofile of the primary tumor was identical to that of the ascitic fluid cells. CONCLUSION: GIST cells may closely mimic adenocarcinoma cells in ascitic fluid. Distinguishing between the two neoplasms has important clinical repercussions and is aided by histochemical and immunocytochemical studies--in particular, c-kit immunostaining.