Uterine Sarcoma With FGFR1-TACC1 Gene Fusion: A Case Report and Review of the Literature.

With the growing availability of RNA sequencing technology in the pathology laboratory, new gene fusion-associated malignancies are increasingly being characterized. In this article, we describe the second ever reported case of a uterine sarcoma harboring a FGFR1-TACC1 gene fusion. The patient, a 53-yr-old perimenopausal woman, was found to have a 6 cm mass spanning the lower uterine segment and endocervix. Histologically, this was a spindle cell neoplasm with coagulative necrosis, moderate cytologic atypia, and increased mitotic activity. By immunohistochemistry, the neoplastic cells coexpressed CD34 and S100, and lacked smooth muscle marker expression. RNA sequencing revealed the presence of a FGFR1-TACC1 gene fusion. This report provides further evidence to suggest that FGFR1-TACC1 may be a recurrent fusion in a subset of uterine sarcomas. RNA sequencing using a panel that includes FGFR-TACC family fusions should be considered for uterine sarcomas that do not fit conventional diagnostic criteria, particularly as tumors with these fusions may be amenable to targeted therapy.

The prognostic role of horizontal and circumferential tumor extent in cervical cancer: Implications for the 2019 FIGO staging system.

OBJECTIVE: The FIGO 2019 update on cervical cancer staging removed horizontal tumor extent (HZTE) as a staging variable. Evidence is needed to substantiate this change. The prognostic significance of HZTE and a related variable, circumferential tumor extent (%CTE), is similarly unknown. We aimed to investigate the association of HZTE and %CTE with survival outcomes in cervical cancer patients. METHODS: We identified patients treated with primary surgery for stage I cervical cancer in a single institution during a 9-year period. HZTE and, when available, %CTE were obtained from pathology records. Cases were staged using 2019 FIGO staging. Correlations between HZTE, %CTE and FIGO stage with recurrence-free (RFS) and disease-specific survival (DSS) were determined using univariable and multivariable analyses. RESULTS: 285 patients were included with a median follow-up of 48 (range 7-123) months. HZTE was statistically associated with RFS and DSS on univariate and multivariate analysis. None of the 168 stage IA patients in our series had tumor recurrence or death during follow-up, including 42 with HZTE ≥7 mm. None of the patients with a tumor horizontal extent <7 mm experienced recurrence or death. %CTE correlated only with RFS on univariate analysis. 2019 FIGO stage did not independently correlate with RFS or DSS in our sample. CONCLUSIONS: HZTE is an independent predictor of survival in cervical carcinoma. In stage IA tumors, however, HZTE does not offer superior prognostic value, supporting the 2019 FIGO recommendations to remove this variable from staging in these cases. HZTE may be useful in larger tumors in which staging depends on maximum tumor size. %CTE is not an independent prognostic variable in cervical cancer, and we advise against its use.

Assessment of Interobserver Agreement Among Gynecologic Pathologists Between Three-Tier Versus Binary Pattern-based Classification Systems for HPV-associated Endocervical Adenocarcinoma.

The three-tier (A vs. B vs. C) pattern-based (Silva) classification system is a strong and fairly reproducible predictor of the risk of lymph node involvement and recurrence of human papillomavirus (HPV)-associated endocervical adenocarcinoma (EA). Recently, a binary pattern-based classification system has been proposed which incorporates the Silva pattern and lymphovascular invasion (LVI) to assign tumors as "low risk" or "high risk" and this may have superior prognostic significance compared with the three-tier system as well as current International Federation of Gynecology and Obstetrics (FIGO) staging of cervix-confined disease. The interobserver reproducibility of this binary system, however, is unknown. Representative slides from 59 HPV-associated EAs (1-3 slides/case) were independently reviewed by 5 gynecologic pathologists who participated in an online training module before the study. In the first review, a pattern was assigned using the three-tier system. On the second review, a "low risk" or "high risk" designation was assigned and the presence or absence of LVI was specifically documented. Interobserver agreement was assessed using Fleiss' kappa. The binary system showed improved interobserver agreement (kappa=0.634) compared with the three-tier system (kappa=0.564), with a higher proportion of cases having agreement between at least 4/5 reviewers (86% vs. 73%). Nineteen and 8 cases showed improved and worse interobserver agreement using the binary system, respectively; the remainder showed no change. 3/5 reviewers showed no intraobserver discrepancy while the remaining 2 did in a small subset of cases (n=2 and 4, respectively). In this study, a binary pattern-based classification system showed improved interobserver agreement compared with the traditional three-tier system.

Barrett's Esophagus and Esophageal Adenocarcinoma: A Histopathological Perspective.

Esophageal adenocarcinoma (EAC) is increasing in prevalence. Barrett's esophagus (BE) has long been recognized as the putative precursor lesion for EAC, but much is still unknown regarding its cell of origin and what molecular factors influence its neoplastic progression. Accurate pathologic assessment of BE biopsies is important for identifying patients most at risk of progressing to EAC, whereas pathologic assessment of EAC specimens plays a major role in influencing therapeutic decision-making.

Gene of the month: FH.

Fumarate hydratase (FH), encoded by the FH gene, is an enzyme which catalyses the conversion of fumarate to L-malate as part of the tricarboxylic acid cycle. Biallelic germline mutations in FH result in fumaric aciduria, a metabolic disorder resulting in severe neurological and developmental abnormalities. Heterozygous germline mutations in FH result in hereditary leiomyomatosis and renal cell carcinoma, a cancer predisposition syndrome. FH deficiency has multiple oncogenic mechanisms including through promotion of aerobic glycolysis, induction of pseudohypoxia, post-translational protein modification and impairment of DNA damage repair by homologous recombination. FH-deficient neoplasms can present with characteristic morphological features that raise suspicion for FH alterations and also frequently demonstrate loss of FH immunoreactivity and intracellular accumulation of 2-succinocysteine, also detected by immunohistochemistry.

Gene of the month: STK11.

STK11 encodes for the protein liver kinase B1, a serine/threonine kinase which is involved in a number of physiological processes including regulation of cellular metabolism, cell polarity and the DNA damage response. It acts as a tumour suppressor via multiple mechanisms, most classically through AMP-activated protein kinase-mediated inhibition of the mammalian target of rapamycin signalling pathway. Germline loss-of-function mutations in STK11 give rise to Peutz-Jeghers syndrome, which is associated with hamartomatous polyps of the gastrointestinal tract, mucocutaneous pigmentation and a substantially increased lifetime risk of many cancers. In the sporadic setting, STK11 mutations are commonly seen in a subset of adenocarcinomas of the lung in addition to a number of other tumours occurring at various sites. Mutations in STK11 have been associated with worse prognoses across a range of malignancies and may be a predictor of poor response to immunotherapy in a subset of lung cancers, though further studies are needed before the presence of STK11 mutations can be implemented as a routine clinical biomarker.

What Are the Burden, Causes, and Costs of Early Hospital Readmissions After Kidney Transplantation?

INTRODUCTION: Kidney transplant recipients are at risk for complications resulting in early hospital readmission. This study sought to determine the incidences, risk factors, causes, and financial costs of early readmissions. DESIGN: This single-centre cohort study included 1461 kidney recipients from 1 Jul 2004 to 31 Dec 2012, with at least 1-year follow-up. Early readmission was defined as hospitalization within 30 or 90-days postdischarge from transplant admission. Associations between various parameters and 30 and 90-days posttransplant were determined using multivariable Cox proportional hazards models. The hospital-associated costs of were assessed. RESULTS: The rates of early readmission were 19.4% at 30 days and 26.8% at 90 days posttransplant. Mean cost per 30-day readmission was 11 606 CAD. Infectious complications were the most common reasons and resulted in the greatest cost burden. Factors associated with 30 and 90-days in multivariable models were recipient history of chronic lung disease (hazard ratio or HR 1.78 [95%CI: 1.14, 2.76] and HR 1.68 [1.14, 2.48], respectively), median time on dialysis (HR 1.07 [95% CI: 1.01, 1.13]and HR 1.06 [95% CI: 1.01, 1.11], respectively), being transplanted preemptively (HR 1.75 [95% CI: 1.07, 2.88] and HR 1.66 [95% CI: 1.07, 2.57], respectively), and having a transplant hospitalization lasting of and more than 11 days (HR 1.52 [95% CI: 1.01, 2.27] and HR 1.65 [95% CI: 1.16, 2.34], respectively). DISCUSSION: Early hospital readmission after transplantation was common and costly. Strategies to reduce the burden of early hospital readmissions are needed for all patients.

CTNNB1 Mutations and Aberrant ß-Catenin Expression in Ovarian Endometrioid Carcinoma: Correlation With Patient Outcome.

CTNNB1 mutations and aberrant ß-catenin expression have adverse prognosis in endometrial endometrioid carcinoma, and recent evidence suggests a prognostic role of ß-catenin in ovarian endometrioid carcinoma. Thus, we aimed to determine the prognostic value of the CTNNB1 mutational status, and its correlation with ß-catenin expression, in a well-annotated cohort of 51 ovarian endometrioid carcinomas. We performed immunohistochemistry for ß-catenin and developed an 11-gene next-generation sequencing panel that included whole exome sequencing of CTNNB1 and TP53. Results were correlated with clinicopathologic variables including disease-free and disease-specific survival. Tumor recurrence was documented in 14 patients (27%), and cancer-related death in 8 patients (16%). CTNNB1 mutations were found in 22 cases (43%), and nuclear ß-catenin in 26 cases (51%). CTNNB1 mutation highly correlated with nuclear ß-catenin (P<0.05). Mutated CTNNB1 status was statistically associated with better disease-free survival (P=0.04, log-rank test) and approached significance for better disease-specific survival (P=0.07). It also correlated with earlier International Federation of Gynecology and Obstetrics stage (P<0.05). Nuclear ß-catenin, TP53 mutations, age, ProMisE group, surface involvement, tumor grade and stage also correlated with disease-free survival. There was no association between membranous ß-catenin expression and disease-free or disease-specific survival. CTNNB1 mutations and nuclear ß-catenin expression are associated with better progression-free survival in patients with OEC. This relationship may be in part due to a trend of CTNNB1-mutated tumors to present at early stage. ß-catenin immunohistochemistry may serve as a prognostic biomarker and a surrogate for CTNN1B mutations in the evaluation of patients with ovarian endometrioid neoplasia, particularly those in reproductive-age or found incidentally without upfront staging surgery.

Clathrin-dependent entry and vesicle-mediated exocytosis define insulin transcytosis across microvascular endothelial cells.

Transport of insulin across the microvasculature is necessary to reach its target organs (e.g., adipose and muscle tissues) and is rate limiting in insulin action. Morphological evidence suggests that insulin enters endothelial cells of the microvasculature, and studies with large vessel-derived endothelial cells show insulin uptake; however, little is known about the actual transcytosis of insulin and how this occurs in the relevant microvascular endothelial cells. We report an approach to study insulin transcytosis across individual, primary human adipose microvascular endothelial cells (HAMECs), involving insulin uptake followed by vesicle-mediated exocytosis visualized by total internal reflection fluorescence microscopy. In this setting, fluorophore-conjugated insulin exocytosis depended on its initial binding and uptake, which was saturable and much greater than in muscle cells. Unlike its degradation within muscle cells, insulin was stable within HAMECs and escaped lysosomal colocalization. Insulin transcytosis required dynamin but was unaffected by caveolin-1 knockdown or cholesterol depletion. Instead, insulin transcytosis was significantly inhibited by the clathrin-mediated endocytosis inhibitor Pitstop 2 or siRNA-mediated clathrin depletion. Accordingly, insulin internalized for 1 min in HAMECs colocalized with clathrin far more than with caveolin-1. This study constitutes the first evidence of vesicle-mediated insulin transcytosis and highlights that its initial uptake is clathrin dependent and caveolae independent.