Cellular heterogeneity and dynamics of the human uterus in healthy premenopausal women.

The human uterus is a complex and dynamic organ whose lining grows, remodels, and regenerates in every menstrual cycle or upon tissue damage. Here we applied single-cell RNA sequencing to profile more the 50,000 uterine cells from both the endometrium and myometrium of 5 healthy premenopausal individuals, and jointly analyzed the data with a previously published dataset from 15 subjects. The resulting normal uterus cell atlas contains more than 167K cells representing the lymphatic endothelium, blood endothelium, stromal, ciliated epithelium, unciliated epithelium, and immune cell populations. Focused analyses within each major cell type and comparisons with subtype labels from prior studies allowed us to document supporting evidence, resolve naming conflicts, and to propose a consensus annotation system of 39 subtypes. We release their gene expression centroids, differentially expressed genes, and mRNA patterns of literature-based markers as a shared community resource. We find many subtypes show dynamic changes over different phases of the cycle and identify multiple potential progenitor cells: compartment-wide progenitors for each major cell type, transitional cells that are upstream of other subtypes, and potential cross-lineage multipotent stromal progenitors that may be capable of replenishing the epithelial, stromal, and endothelial compartments. When compared to the healthy premenopausal samples, a postpartum and a postmenopausal uterus sample revealed substantially altered tissue composition, involving the rise or fall of stromal, endothelial, and immune cells. The cell taxonomy and molecular markers we report here are expected to inform studies of both basic biology of uterine function and its disorders. SIGNIFICANCE: We present single-cell RNA sequencing data from seven individuals (five healthy pre-menopausal women, one post-menopausal woman, and one postpartum) and perform an integrated analysis of this data alongside 15 previously published scRNA-seq datasets. We identified 39 distinct cell subtypes across four major cell types in the uterus. By using RNA velocity analysis and centroid-centroid comparisons we identify multiple computationally predicted progenitor populations for each of the major cell compartments, as well as potential cross-compartment, multi-potent progenitors. While the function and interactions of these cell populations remain to be validated through future experiments, the markers and their "dual characteristics" that we describe will serve as a rich resource to the scientific community. Importantly, we address a significant challenge in the field: reconciling multiple uterine cell taxonomies being proposed. To achieve this, we focused on integrating historical and contemporary knowledge across multiple studies. By providing detailed evidence used for cell classification we lay the groundwork for establishing a stable, consensus cell atlas of the human uterus.

Endometriosis first presenting in pleural fluid cytology.

Most patients with thoracic endometriosis present with catamenial pneumothorax, a rare condition in which recurrent episodes occur within 72 h before or after the start of menstruation. We report a case of thoracic endometriosis presenting with recurrent bloody pleural effusions without pneumothorax diagnosed on pleural fluid cytology. We describe the cytomorphology and immunoprofile of thoracic endometriosis and discuss the differential diagnoses, including neoplastic processes. We also highlight the importance of communication with clinicians for timeliness of diagnosis and treatment, especially when thoracic endometriosis is not suspected.

Human iPSC-derived astrocytes generated from donors with globoid cell leukodystrophy display phenotypes associated with disease.

Globoid cell leukodystrophy (Krabbe disease) is a fatal neurodegenerative, demyelinating disease caused by dysfunctional activity of galactosylceramidase (GALC), leading to the accumulation of glycosphingolipids including psychosine. While oligodendrocytes have been extensively studied due to their high levels of GALC, the contribution of astrocytes to disease pathogenesis remains to be fully elucidated. In the current study, we generated induced pluripotent stem cells (iPSCs) from two donors with infantile onset Krabbe disease and differentiated them into cultures of astrocytes. Krabbe astrocytes recapitulated many key findings observed in humans and rodent models of the disease, including the accumulation of psychosine and elevated expression of the pro-inflammatory cytokine IL-6. Unexpectedly, Krabbe astrocytes had higher levels of glucosylceramide and ceramide, and displayed compensatory changes in genes encoding glycosphingolipid biosynthetic enzymes, suggesting a shunting away from the galactosylceramide and psychosine pathway. In co-culture, Krabbe astrocytes negatively impacted the survival of iPSC-derived human neurons while enhancing survival of iPSC-derived human microglia. Substrate reduction approaches targeting either glucosylceramide synthase or serine palmitoyltransferase to reduce the sphingolipids elevated in Krabbe astrocytes failed to rescue their detrimental impact on neuron survival. Our results suggest that astrocytes may contribute to the progression of Krabbe disease and warrant further exploration into their role as therapeutic targets.

Shifting the Soil: Metformin Treatment Decreases the Protumorigenic Tumor Microenvironment in Epithelial Ovarian Cancer.

Controversy persists regarding metformin's role in cancer therapy. Our recent work suggested metformin acts by impacting the tumor microenvironment (TME), normalizing the epigenetic profile of cancer-associated mesenchymal stem cells (CA-MSC). As CA-MSC can negatively impact tumor immune infiltrates, we evaluated metformin's impact on the human TME, focusing on the interplay of stroma and immune infiltrates. Tumor samples from (i) 38 patients treated with metformin and chemotherapy and (ii) 44 non-metformin matched controls were included in a tissue microarray (TMA). The TMA was used to compare the presence of CA-MSC, desmoplasia and immune infiltrates in the TME. In vitro and in vivo models examined metformin's role in alteration of the CA-MSC phenotype. The average percentage of CA-MSC was significantly lower in metformin-treated than in chemotherapy alone-treated tumors (p = 0.006). There were fewer regulatory T-cells in metformin-treated tumors (p = 0.043). Consistent with CA-MSC's role in excluding T-cells from tumor islets, the T-cells were primarily present within the tumor stroma. Evaluation of metformin's impact in vitro suggested that metformin cannot reverse a CA-MSC phenotype; however, the in vivo model where metformin was introduced prior to the establishment of the CA-MSC phenotype supported that metformin can partially prevent the reprogramming of normal MSC into CA-MSC. Metformin treatment led to a decrease in both the presence of protumorigenic CA-MSC and in immune exclusion of T cells, leading to a more immune-permissive environment. This suggests clinical utility in prevention and in treatment for early-stage disease and putatively in immune therapy.

Cellular heterogeneity of human fallopian tubes in normal and hydrosalpinx disease states identified using scRNA-seq.

Fallopian tube (FT) homeostasis requires dynamic regulation of heterogeneous cell populations and is disrupted in infertility and ovarian cancer. Here, we applied single-cell RNA-seq to profile 59,738 FT cells from four healthy, pre-menopausal subjects. The resulting cell atlas contains 12 major cell types representing epithelial, stromal, and immune compartments. Re-clustering of epithelial cells identified four ciliated and six non-ciliated secretory epithelial subtypes, two of which represent potential progenitor pools: one leading to mature secretory cells and the other contributing to either ciliated cells or one of the stromal cell types. To understand how FT cell numbers and states change in a disease state, we analyzed 17,798 cells from two hydrosalpinx samples and observed shifts in epithelial and stromal populations and cell-type-specific changes in extracellular matrix and TGF-ß signaling; this underscores fibrosis pathophysiology. This resource is expected to facilitate future studies aimed at expanding understanding of fallopian tube homeostasis in normal development and disease.

Progression of Peritoneal Mesothelioma In Situ to Invasive Mesothelioma Arising in the Setting of Endometriosis With Germline BAP1 Mutation: A Case Report.

Mesothelioma in situ has been proposed as a precursor to malignant mesothelioma arising in the pleura or peritoneum. We report a case of malignant peritoneal mesothelioma which progressed from mesothelioma in situ over a 10-mo period in a 24-yr-old woman with stage IV endometriosis. Initial surgery showed deeply infiltrative endometriosis with progestin effect. Postoperatively the patient had intractable pelvic pain and vaginal discharge. Imaging studies were negative. Repeat laparoscopy 10 mo later revealed vesicular lesions on the omentum and pinpoint white lesions studding the small bowel, appendix, and pelvic peritoneum. A diagnosis of epithelioid mesothelioma was established on biopsy of the omentum and confirmed by immunohistochemistry showing complete loss of BRCA1-associated protein-1 (BAP1) nuclear staining. Retrospectively, BAP1 loss was identified in the cytologically bland, single-layer surface mesothelium of the prior resection specimen, consistent with mesothelioma in situ . The patient underwent genetic testing and was found to have a pathogenic germline mutation in BAP1 .

Hyperexcitable Phenotypes in Induced Pluripotent Stem Cell-Derived Neurons From Patients With 15q11-q13 Duplication Syndrome, a Genetic Form of Autism.

BACKGROUND: Chromosome 15q11-q13 duplication syndrome (Dup15q) is a neurogenetic disorder caused by duplications of the maternal copy of this region. In addition to hypotonia, motor deficits, and language impairments, patients with Dup15q commonly meet the criteria for autism spectrum disorder and have a high prevalence of seizures. It is known from mouse models that synaptic impairments are a strong component of Dup15q pathophysiology; however, cellular phenotypes that relate to seizures are less clear. The development of patient-derived induced pluripotent stem cells provides a unique opportunity to study human neurons with the exact genetic disruptions that cause Dup15q. METHODS: Here, we explored electrophysiological phenotypes in induced pluripotent stem cell-derived neurons from 4 patients with Dup15q compared with 6 unaffected control subjects, 1 patient with a 15q11-q13 paternal duplication, and 3 patients with Angelman syndrome. RESULTS: We identified several properties of Dup15q neurons that could contribute to neuronal hyperexcitability and seizure susceptibility. Compared with control neurons, Dup15q neurons had increased excitatory synaptic event frequency and amplitude, increased density of dendritic protrusions, increased action potential firing, and decreased inhibitory synaptic transmission. Dup15q neurons also showed impairments in activity-dependent synaptic plasticity and homeostatic synaptic scaling. Finally, Dup15q neurons showed an increased frequency of spontaneous action potential firing compared with control neurons, in part due to disruption of KCNQ2 potassium channels. CONCLUSIONS: Together, these data point to multiple electrophysiological mechanisms of hyperexcitability that may provide new targets for the treatment of seizures and other phenotypes associated with Dup15q.

Fertility and Pregnancy Outcomes After Conservative Management of Adenocarcinoma In Situ of the Cervix.

OBJECTIVE: The aim of the study was to evaluate the pregnancy outcomes of women who underwent conservative management of adenocarcinoma in situ (AIS). MATERIALS AND METHODS: We conducted a retrospective chart review of patients diagnosed with AIS at a single tertiary institution between January 1, 1991, and December 31, 2019. We collected demographic data, AIS-specific information, and fertility outcomes and performed bivariate analyses to compare demographic characteristics and AIS-specific information between patients with and without hysterectomy after diagnosis. Patients with conservative management who achieved pregnancy were described. RESULTS: Among 87 patients with AIS, 38 (44%) underwent a hysterectomy within 6 months of diagnosis and 49 (56%) underwent conservative management. Six of 19 patients (32%) had residual AIS despite undergoing definitive management after an excisional procedure with negative margins and negative endocervical curettage (ECC). Nine of 19 patients (47%) had residual AIS after an excisional procedure with positive margins and/or a positive ECC. Patients who opted for conservative management were younger (median = 31.6 [interquartile range = 27.4-34.9] vs 38.5 y [32.3-44.8 y], p < .001) and nulligravid. Among patients with conservative management, there were 15 pregnancies and 14 live births (29%). Seven were preterm, although 2 were for medical indications. CONCLUSIONS: Residual AIS in patients with negative margins and ECC leading to definitive hysterectomy (32%) and the rate of preterm birth (36%) were higher than previous reports and nationally reported rates. However, only 1 patient had a preterm birth before 34 weeks. These findings reflect important information for counseling patients who elect for conservative management of AIS.

Two rare presentations of embryonal rhabdomyosarcoma of the cervix in teenagers at a low-resource teaching hospital in Ghana: A case series.

We report two cases of embryonal rhabdomyosarcoma (ERMS) of the cervix in teenagers presenting to Komfo Anokye Teaching Hospital in Kumasi, Ghana within one month of each other. Between October and November 2019, two patients presented with ERMS of the cervix. They both underwent fertility-sparing surgery followed by chemotherapy with vincristine, actinomycin-D, and cyclophosphamide. Preoperative workup for the two patients was minimal due to limited availability and high cost of imaging in a low-resource setting. Both patients were discussed at a multidisciplinary tumor board meeting to guide best management practices. Both patients had local surgical resection with histological confirmation of ERMS and negative margins, followed by six cycles of vincristine, actinomycin-D, and cyclophosphamide. Neither of the patients had perioperative complications or received radiation therapy. At the time of publication, both patients are currently alive and without evidence of recurrence. Fertility-sparing surgery followed by chemotherapy for patients with ERMS of the cervix is accessible in low-income countries.

Conducting School Suicide Risk Assessment in Distance Learning Environments.

The social distancing mandate, implemented in response to the coronavirus disease 2019 (COVID-19) global pandemic, has guided many schools to deliver instruction via distance learning. Among the many challenges generated by this delivery system is the need for school mental health services, including school suicide prevention and intervention, to be conducted remotely. After briefly discussing the magnitude of the problem of youth suicide and how the COVID-19 pandemic has likely increased risk for youth suicidal ideation and behaviors, this article provides guidance on how school systems can prepare for and conduct suicide risk assessments in distance learning environments.

Expanding the Morphologic, Immunohistochemical, and HPV Genotypic Features of High-grade Squamous Intraepithelial Lesions of the Vulva With Morphology Mimicking Differentiated Vulvar Intraepithelial Neoplasia and/or Lichen Sclerosus.

Squamous cell carcinoma of the vulva can arise through 2 pathways: human papillomavirus (HPV)-dependent high-grade squamous intraepithelial lesions (previously termed usual vulvar intraepithelial neoplasia) or HPV-independent (differentiated vulvar intraepithelial neoplasia, dVIN). Distinguishing between the 2 types can be clinically and histologically difficult. A subset of high-grade squamous intraepithelial lesions with superimposed chronic inflammation mimicking dVIN has recently been reported; p53 shows characteristic mid-epithelial staining (with basal sparing) in such cases. The pathology databases of 2 academic institutions were searched for vulva specimens with corresponding p53 and p16 immunohistochemical stains, yielding 38 specimens (from 27 patients). In situ hybridization and multiplex polymerase chain reaction-MassArray for high-risk HPV were performed on at least 1 block from each patient. All cases resembled dVIN or lichen sclerosus morphologically, but with a higher degree of atypia. All but 1 case demonstrated mid-epithelial p53 staining with basal sparing by immunohistochemistry. All cases showed block positivity for p16 and at least patchy positivity by HPV in situ hybridization. Of the 23 cases with valid HPV DNA polymerase chain reaction results, 15 were positive and 8 were negative. Of the positive cases, HPV16 was identified in 10 cases, with other high-risk types in the remaining 5. To our knowledge, this is the largest cohort of high-grade squamous intraepithelial lesions mimicking dVIN reported to date. Prior studies reported positivity for HPV16 in all cases tested, however, we found HPV16 in only 67% of HPV positive cases. This case series highlights the importance of immunohistochemistry, and occasionally HPV in situ hybridization, for accurate diagnosis, and expands the spectrum of associated HPV types.

Induced pluripotent stem cell reprogramming-associated methylation at the GABRA2 promoter and chr4p12 GABAA subunit gene expression in the context of alcohol use disorder.

Twin studies indicate that there is a significant genetic contribution to the risk of developing alcohol use disorder (AUD). With the exception of coding variants in ADH1B and ALDH2, little is known about the molecular effects of AUD-associated loci. We previously reported that the AUD-associated synonymous polymorphism rs279858 within the GABAA α2 receptor subunit gene, GABRA2, was associated with gene expression of the chr4p12 GABAA subunit gene cluster in induced pluripotent stem cell (iPSC)-derived neural cultures. Based on this and other studies that showed changes in GABRA2 DNA methylation associated with schizophrenia and aging, we examined methylation in GABRA2. Specifically, using 69 iPSC lines and neural cultures derived from 47 of them, we examined whether GABRA2 rs279858 genotype predicted methylation levels and whether methylation was related to GABAA receptor subunit gene expression. We found that the GABRA2 CpG island undergoes random stochastic methylation during reprogramming and that methylation is associated with decreased GABRA2 gene expression, an effect that extends to the GABRB1 gene over 600 kb distal to GABRA2. Further, we identified additive effects of GABRA2 CpG methylation and GABRA2 rs279858 genotype on expression of the GABRB1 subunit gene in iPSC-derived neural cultures.

Molecular Correlates of Topiramate and GRIK1 rs2832407 Genotype in Pluripotent Stem Cell-Derived Neural Cultures.

BACKGROUND: There is growing evidence that the anticonvulsant topiramate is efficacious in reducing alcohol consumption. Further, an intronic single nucleotide polymorphism (rs2832407, C A) in the GRIK1 gene, which encodes the GluK1 subunit of the excitatory kainate receptor, predicted topiramate's effectiveness in reducing heavy drinking in a clinical trial. The molecular correlates of GRIK1 genotype that may relate to topiramate's ability to reduce drinking remain unknown. METHODS: We differentiated induced pluripotent stem cells (iPSCs) characterized by GRIK1 rs2832407 genotype from 8 A/A and 8 C/C donors into forebrain-lineage neural cultures. Our differentiation protocol yielded mixed neural cultures enriched for glutamatergic neurons. Basal mRNA expression of the GRIK1 locus was examined via quantitative polymerase chain reaction (qPCR). The effects of acute topiramate exposure on excitatory spontaneous synaptic activity were examined via whole-cell patch-clamp electrophysiology. Results were compared and contrasted between iPSC donor genotypes. RESULTS: Although characterization of the GRIK1 locus revealed no effect of rs2832407 genotype on GRIK1 isoform mRNA expression, a significant difference was observed on GRIK1 antisense-2 expression, which was greater in C/C neural cultures. Differential effects of acute exposure to 5 µM topiramate were observed on spontaneous synaptic activity in A/A versus C/C neurons, with a smaller reduction in excitatory event frequency observed in C/C donor neurons. CONCLUSIONS: This work highlights the use of iPSC technologies to study pharmacogenetic treatment effects in psychiatric disorders and furthers our understanding of the molecular effects of topiramate exposure in human neural cells.

Predictive Value of an Alternative Strategy for Measuring Depth and Size of Stage 1 Vulvar Squamous Cell Carcinoma.

OBJECTIVES: Despite poor reproducibility for measuring vulvar cancer depth, 1-mm or greater invasion triggers lymphadenectomy for small tumors. Previous literature suggests that measuring depth from the nearest dysplastic rete peg (alternative method) rather than highest dermal papilla (conventional method) may be acceptable. METHODS: Pathologic staging and follow-up information were recorded for 100 pT1 vulvar squamous cell carcinoma (SCC) resected from 1990 to 2019. Conventional depth, alternative depth, gross/clinical size, and size of the invasive component were measured for each tumor. In this retrospective study, we evaluated which clinicopathologic factors were most predictive of lymph node involvement and recurrence. RESULTS: Depending on the measurements used (conventional vs alternative depth, clinical lesion size vs cumulative extent of invasive component), between 1 and 18 cases were downstaged to pT1a. All such cases were pN0, without lymphovascular or perineural invasion. Infiltrative cords (hazard ratio [HR] = 5.15; 95% CI = 1.63-16.2; p = .005) and perineural invasion (HR = 3.16; 1.18-8.45; p = .022) were most strongly associated with groin recurrence. Of staging criteria evaluated, only cumulative extent of the invasive component 2 cm or greater was significantly associated with groin recurrence (HR = 2.87; 1.01-8.17; p = .048). The Kaplan-Meier curves for local recurrence-free survival by stage did not show significant separation regardless of method. CONCLUSIONS: Patients downstaged using alternative measurement techniques lacked nodal disease/recurrence; one-third of those with nodal sampling experienced postoperative morbidity. Our data suggest that the use of alternative depth and cumulative extent of invasion could safely allow some conventional stage IB vulvar SCC patients to avoid groin surgery, thereby reducing treatment-related morbidity.

Parentage of Hydatidiform Moles.

We were presented with the STR (short tandem repeat) profiles from two separate paternity trios. Each trio consisted of a mother, an alleged father, and products of conception (POC) that contained a hydatidiform mole but no visible fetus. In both cases, antecedent pregnancies had followed alleged sexual assaults. Mole classification and pathogenesis are described in order to explain the analyses and statistical reasoning used in each case. One mole exhibited several loci with two different paternal alleles, indicating it was a dispermic (heterozygous) mole. Maternal decidua contaminated the POC, preventing the identification of paternal obligate alleles (POAs) at some loci. The other mole exhibited only one paternal allele/locus at all loci and no maternal alleles, indicating it was a diandric and diploid (homozygous) mole. In each case, traditional calculations were used to determine paternity indices (PIs) at loci that exhibited one paternal allele/locus. PIs at mole loci with two different paternal alleles/locus were calculated from formulas first used for child chimeras that are always dispermic. Combined paternity indices in both mole cases strongly supported the paternity of each suspect.

Prenatal Testosterone Excess Disrupts Placental Function in a Sheep Model of Polycystic Ovary Syndrome.

Polycystic ovary syndrome (PCOS) is a common condition of reproductive-aged women. In a well-validated sheep model of PCOS, testosterone (T) treatment of pregnant ewes culminated in placental insufficiency and intrauterine growth restriction of offspring. The purpose of this study was to explore specific mechanisms by which T excess compromises placental function in early, mid, and late gestation. Pregnant Suffolk sheep received T propionate 100 mg intramuscularly or control vehicle twice weekly from gestational days (GD) 30 to 90 (term = 147 days). Placental harvest occurred at GD 65, 90, and 140. Real-time RT-PCR was used to assess transcript levels of proinflammatory (TNF, IL1B, IL6, IL8, monocyte chemoattractant protein-1/chemokine ligand 2, cluster of differentiation 68), antioxidant (glutathione reductase and superoxide dismutase 1 and 2), and angiogenic [vascular endothelial growth factor (VEGF) and hypoxia-inducible factor 1α (HIF1A)] genes. Lipid accumulation was assessed using triglyceride assays and Oil Red O staining. Placental measures of oxidative and nitrative stress included the thiobarbituric acid reactive substance assay and high-pressure liquid chromatography. Tissue fibrosis was assessed with Picrosirius Red staining. Student t tests and Cohen effect-size analyses were used for statistical analysis. At GD 65, T-treated placentomes showed increased lipid accumulation and collagen deposition. Notable findings at GD 90 were a significant increase in HIF1A expression and a large effect increase in VEGF expression. At GD 140, T-treated placentomes displayed large effect increases in expression of hypoxia and inflammatory markers. In summary, T treatment during early pregnancy induces distinct gestational age-specific effects on the placental milieu, which may underlie the previously observed phenotype of placental insufficiency.

Alcohol-responsive genes identified in human iPSC-derived neural cultures.

Alcohol use contributes to numerous diseases and injuries. The nervous system is affected by alcohol in diverse ways, though the molecular mechanisms of these effects are not clearly understood. Using human-induced pluripotent stem cells (iPSCs), we developed a neural cell culture model to identify the mechanisms of alcohol's effects. iPSCs were generated from fibroblasts and differentiated into forebrain neural cells cultures that were treated with 50 mM alcohol or sham conditions (same media lacking alcohol) for 7 days. We analyzed gene expression using total RNA sequencing (RNA-seq) for 34 samples derived from 10 subjects and for 10 samples from 5 subjects in an independent experiment that had intermittent exposure to the same dose of alcohol. We also analyzed genetic effects on gene expression and conducted a weighted correlation network analysis. We found that differentiated neural cell cultures have the capacity to recapitulate gene regulatory effects previously observed in specific primary neural tissues and identified 226 genes that were differentially expressed (FDR < 0.1) after alcohol treatment. The effects on expression included decreases in INSIG1 and LDLR, two genes involved in cholesterol homeostasis. We also identified a module of 58 co-expressed genes that were uniformly decreased following alcohol exposure. The majority of these effects were supported in independent alcohol exposure experiments. Enrichment analysis linked the alcohol responsive genes to cell cycle, notch signaling, and cholesterol biosynthesis pathways, which are disrupted in several neurological disorders. Our findings suggest that there is convergence between these disorders and the effects of alcohol exposure.

Rare Clinical Entity: Metastatic malignant struma ovarii diagnosed during pregnancy - Lessons for management.

BACKGROUND: Malignant struma ovarii is an ovarian teratoma containing at least 50% thyroid tissue which has the potential to metastasize and produce thyroid hormone. Given its rarity, management strategies are not well-established. We report a case of metastatic malignant struma ovarii discovered during pregnancy with lessons for evaluation and management. CASE PRESENTATION: A 30-year-old woman who was two months pregnant was discovered to have struma ovarii with over half of the struma comprised of papillary thyroid cancer. Following tumor resection, delivery, and thyroidectomy, she underwent evaluation with stimulated thyroglobulin testing and diagnostic staging sodium iodide-131 scan (I-131), which revealed the presence of skeletal metastases. Following administration of 320 mCi I-131, post-therapy scan also showed miliary pulmonary metastases with improved ability to localize the bony and pulmonary metastases with concurrent SPECT/CT imaging. A second dosimetry-guided I-131 therapy resulted in complete resolution of pulmonary metastases; however, small foci of residual bone disease persisted. Post-therapy scans demonstrated additional findings not shown on diagnostic I-131 scans obtained prior to both her initial and second I-131 therapy. CONCLUSIONS: SPECT/CT provides accurate anatomic correlation and localization of metastatic foci and can serve as a baseline study to assess interval response to treatment. Post-therapy scans should always be obtained when I-131 treatment is administered, as additional findings may be revealed versus low dose I-131 activity diagnostic scans. This patient had a high metastatic burden that would not have been discovered in a timely fashion with the conservative approach advocated by others. Thyroidectomy followed by a diagnostic staging radioiodine scan and a stimulated thyroglobulin level should be considered in patients with malignant struma ovarii for guiding therapeutic I-131 administration as metastatic risk is difficult to predict based on histopathologic examination.

High Variability in Lymph Node Counts Among an International Cohort of Pathologists: Questioning the Scientific Validity of Node Counts.

Background: The enumeration of lymph nodes (LNs) from surgical specimens plays a critical role in the staging of patients with cancer. LN count (LNC) can affect prognosis, staging, adequacy of resection, and/or eligibility for clinical trials. However, there is no standard method for counting LNs. Most studies in the literature site the pathology report as the source of LN data, without discussion of the counting criteria. Patients and Methods: Four microscopic slides from separate pelvic LN dissections were digitally scanned and uploaded with their gross descriptions to an online library and an online survey. Respondents were asked how many LNs they would count per slide as part of a staging procedure. The survey was distributed to an international cohort of pathologists. Results: A total of 122 surveys were returned: 79 from practicing pathologists and 43 from residents/fellows. There was no statistical difference between the groups. All slides showed significant individual variability. The LNC range for each slide was as follows: slide 1, 1-3; slide 2, 0-13; slide 3, 1-8; slide 4, 1-11. The intraclass correlation (ICC) for all responders was 0.26 (95% CI, 0.05