Incorporating placental pathology into clinical care and research.

Despite recent standardization of placental evaluation and establishment of criteria for diagnosis of major patterns of placental injury, placental pathological examination remains undervalued and under-utilized. The placenta can harbor a significant amount of information relevant to both the pregnant person and offspring. Placental pathology can also provide a significant context for pathophysiological study of adverse pregnancy outcomes, helping to optimally subcategorize the 'great obstetric syndromes' of pre-eclampsia (PE), spontaneous preterm birth (sPTB), and fetal growth restriction (FGR), and to identify causes of stillbirth. We hereby propose that placental evaluation should be incorporated into routine delivery of obstetric and neonatal care, and further suggest that its integration into clinical, translational, and basic research could significantly advance our understanding of pregnancy complications and adverse neonatal outcomes.

CAR expression in invasive breast carcinoma and its effect on adenovirus transduction efficiency.

BACKGROUND: Breast cancer is the second leading cause of death in women, with invasive ductal carcinoma (IDC) and invasive lobular carcinoma (ILC) as the two most common forms of invasive breast cancer. While estrogen receptor positive (ER+) IDC and ILC are treated similarly, the multifocality of ILC presents challenges in detection and treatment, worsening long-term clinical outcomes in patients. With increasing documentation of chemoresistance in ILC, additional treatment options are needed. Oncolytic adenoviral therapy may be a promising option, but cancer cells must express the coxsackievirus & adenovirus receptor (CAR) for adenoviral therapy to be effective. The present study aims to evaluate the extent to which CAR expression is observed in ILC in comparison to IDC, and how the levels of CAR expression correlate with adenovirus transduction efficiency. The effect of liposome encapsulation on transduction efficiency is also assessed. METHODS: To characterize CAR expression in invasive breast carcinoma, 36 formalin-fixed paraffin-embedded (FFPE) human breast tumor samples were assayed by CAR immunohistochemistry (IHC). Localization of CAR in comparison to other junctional proteins was performed using a multiplex immunofluorescence panel consisting of CAR, p120-catenin, and E-cadherin. ILC and IDC primary tumors and cell lines were transduced with E1- and E3-deleted adenovirus type 5 inserted with a GFP transgene (Ad-GFP) and DOTAP liposome encapsulated Ad-GFP (DfAd-GFP) at various multiplicities of infection (MOIs). Transduction efficiency was measured using a fluorescence plate reader. CAR expression in the human primary breast carcinomas and cell lines was also evaluated by IHC. RESULTS: We observed membranous CAR, p120-catenin and E-cadherin expression in IDC. In ILC, we observed cytoplasmic expression of CAR and p120-catenin, with absent E-cadherin. Adenovirus effectively transduced high-CAR IDC cell lines, at MOIs as low as 12.5. Ad-GFP showed similar transduction as DfAd-GFP in high-CAR IDC cell lines. Conversely, Ad-GFP transduction of ILC cell lines was observed only at MOIs of 50 and 100. Furthermore, Ad-GFP did not transduce CAR-negative IDC cell lines even at MOIs greater than 100. Liposome encapsulation (DfAd-GFP) improved transduction efficiency 4-fold in ILC and 17-fold in CAR-negative IDC cell lines. CONCLUSION: The present study demonstrates that oncolytic adenoviral therapy is less effective in ILC than IDC due to differences in spatial CAR expression. Liposome-enhanced delivery may be beneficial for patients with ILC and tumors with low or negative CAR expression to improve adenoviral therapeutic effectiveness.

Comprehensive next-generation sequencing identifies novel putative pathogenic or likely pathogenic germline variants in patients with concurrent tubo-ovarian and endometrial serous and endometrioid carcinomas or precursors.

BACKGROUND: Endometrial serous carcinoma (ESC) and tubo-ovarian high-grade serous carcinoma (HGSC) are characterized by late-stage presentation and high mortality. Current guidelines for prevention recommend risk-reducing salpingo-oophorectomy (RRSO) in patients with hereditary mutations in cancer susceptibility genes. However, HGSC displays extensive genetic heterogeneity with alterations in 168 genes identified in TCGA study, but current germline testing panels are often limited to the handful of recurrently mutated genes, leaving families with rare hereditary gene mutations potentially at-risk. OBJECTIVE: To determine if there are rare germline mutations that may aid in early identification of more patients at-risk for ESC and/or HGSC by evaluating patients with concurrent ESC, HGSC or precursor lesions, and endometrial atypical hyperplasia (CAH) or low-grade endometrial endometrioid adenocarcinoma (LGEEA). METHODS: We performed targeted next-generation sequencing using TSO 500, a 523 gene panel, on formalin-fixed paraffin-embedded tumor and matched benign non-tumor tissue blocks from 5 patients with concurrent ESC, HGSC or precursor lesions, and CAH or LGEEA. RESULTS: We identified germline pathogenic, likely pathogenic or uncertain significance variants in cancer susceptibility genes in 4 of 5 patients - affected genes included GLI1, PIK3R1, FOXP1, FANCD2, INPP4B and H3F3C. Notably, none of these genes were included in the commercially available germline testing panels initially used to evaluate the patients at the time of their diagnoses. CONCLUSION: Comprehensive germline testing of patients with concurrent LGEEA or CAH and ESC, HGSC or precursor lesions may aid in early identification of relatives at-risk for cancer who may be candidates for RRSO with hysterectomy.

Fumarate Hydratase-Deficient Leiomyoma of the Uterine Corpus: Comparative Morphologic Analysis of Protein-Deficient Tumors With and Without Pathogenic Germline Fumarate Hydratase Gene Mutations.

Deficiency of fumarate hydratase (FH) protein expression in uterine corpus leiomyomas may be attributable to either germline or somatic mutations of the FH gene, the former being definitional for the hereditary leiomyomatosis and renal cell cancer syndrome. The authors assess whether, using previously reported FH-associated morphologic features, FH protein-deficient uterine corpus leiomyomas associated with a pathogenic germline mutations of the FH gene (group 1) are distinguishable from FH protein-deficient uterine corpus leiomyomas without such mutations (and whose FH protein loss is presumed to be attributable to somatic/epigenetic inactivation or other unknown phenomena: group 2). Groups 1 and 2 were compared regarding a variety of clinicopathologic features, including 7 core "FH-associated" tumoral morphologic features: staghorn vasculature; alveolar-type edema; bizarre nuclei; chain-like tumor nuclei; hyaline cytoplasmic globules; prominent nucleoli, intranuclear inclusions, and perinucleolar halos; and prominent eosinophilic/fibrillary cytoplasm. Among 2418 patients diagnosed with uterine corpus leiomyoma during the study period, FH-associated morphologic features were reported in 1.5% (37 patients), and FH immunohistochemistry was performed in 29 (1.19%). Fourteen (48.27%) of the 29 patients showed FH protein deficiency by immunohistochemistry. Twelve patients underwent germline testing, of which 8 (66.7%) were classified as group 1 and 4 (33.3%) as group 2. FH protein-deficient tumors were larger (10.44 vs 4.08 cm, P = 0.01) and associated with younger patients (42.05 vs 47.97, P = 0.004) than 370 randomly selected uterine leiomyoma controls. Groups 1 and 2 showed no significant differences in patient age and tumor size. In group 1 tumors, the FH-associated morphologic features were generally present diffusely; all group 1 tumors displayed ≥5 FH-associated features, whereas all group 2 tumors displayed <5 FH-associated features (means 6.5 ± 0.53 vs 3.5 ± 1.00, P < 0.001). Notably, eosinophilic/fibrillary cytoplasm and alveolar-type edema were each significantly more prevalent in group 1 tumors than group 2 tumors (P = 0.018 for both). No single morphologic feature was found to be completely sensitive and specific in making the distinction between group 1 and 2 tumors. Our findings suggest that groups 1 and 2 are unlikely to be morphologically distinguishable by individual morphologic features. Whether there is a combination of features that can reliably make this distinction is unclear and will require additional studies with larger cohorts.

High placental expression of FLT1, LEP, PHYHIP and IL3RA - In persons of African ancestry with severe preeclampsia.

INTRODUCTION: Mortality from preeclampsia (PE) and PE-associated morbidities are 3-to 5-fold higher in persons of African ancestry than in those of Asian and European ancestries. METHODS: To elucidate placental contribution to worse PE outcomes in African ancestry pregnancies, we performed bulk RNA sequencing on 50 placentas from persons with severe PE (sPE) of African (n = 9), Asian (n = 18) and European (n = 23) ancestries and 73 normotensive controls of African (n = 10), Asian (n = 15) and European (n = 48) ancestries. RESULTS: Previously described canonical preeclampsia genes, involved in metabolism and hypoxia/angiogenesis including: LEP, HK2, FSTL3, FLT1, ENG, TMEM45A, ARHGEF4 and HTRA1 were upregulated sPE versus normotensive placentas across ancestries. LTF, NPR3 and PHYHIP were higher in African vs. Asian ancestry sPE placentas. Allograft rejection/adaptive immune response genes were upregulated in placentas from African but not in Asian or European ancestry sPE patients; IL3RA was of particular interest because the patient with the highest placental IL3RA expression, a person of African ancestry with sPE, developed postpartum cardiomyopathy, and was the only patient out of 123, that developed this condition. Interestingly, the sPE patients with the highest IL3RA expression among persons of Asian and European ancestries developed unexplained tachycardia peripartum, necessitating echocardiography in the European ancestry patient. The association between elevated placental IL3RA levels and unexplained tachycardia or peripartum cardiomyopathy was found to be significant in the 50 sPE patients (p = .0005). DISCUSSION: High placental upregulation of both canonical preeclampsia and allograft rejection/adaptive immune response genes may contribute to worse PE outcomes in African ancestry sPE patients.

A Local and Abscopal Effect Observed with Liposomal Encapsulation of Intratumorally Injected Oncolytic Adenoviral Therapy.

This study evaluated the in vivo therapeutic efficacy of oncolytic serotype 5 adenovirus TAV255 in CAR-deficient tumors. In vitro experiments were performed with cell lines that expressed different levels of CAR (HEK293, A549, CT26, 4T1, and MCF-7). Low CAR cells, such as CT26, were poorly transduced by Ad in vitro unless the adenovirus was encapsulated in liposomes. However, the CT26 tumor in an immune-competent mouse model responded to the unencapsulated TAV255; 33% of the tumors were induced into complete remission, and mice with complete remission rejected the rechallenge with cancer cell injection. Encapsulation of TAV255 improves its therapeutic efficacy by transducing more CT26 cells, as expected from in vitro results. In a bilateral tumor model, nonencapsulated TAV255 reduced the growth rate of the locally treated tumors but had no effect on the growth rate of the distant tumor site. Conversely, encapsulated TAV255-infected CT26 induced a delayed growth rate of both the primary injected tumor and the distant tumor, consistent with a robust immune response. In vivo, intratumorally injected unencapsulated adenoviruses infect CAR-negative cells with only limited efficiency. However, unencapsulated adenoviruses robustly inhibit the growth of CAR-deficient tumors, an effect that constitutes an 'in situ vaccination' by stimulating cytotoxic T cells.

Activation of the Interferon Pathway in Trophoblast Cells Productively Infected with SARS-CoV-2.

SARS-CoV-2 infection during pregnancy has been associated with poor maternal and neonatal outcomes and placental defects. The placenta, which acts as a physical and immunological barrier at the maternal-fetal interface, is not established until the end of the first trimester. Therefore, localized viral infection of the trophoblast compartment early in gestation could trigger an inflammatory response resulting in altered placental function and consequent suboptimal conditions for fetal growth and development. In this study, we investigated the effect of SARS-CoV-2 infection in early gestation placentae using placenta-derived human trophoblast stem cells (TSCs), a novel in vitro model, and their extravillous trophoblast (EVT) and syncytiotrophoblast (STB) derivatives. SARS-CoV-2 was able to productively replicate in TSC-derived STB and EVT, but not undifferentiated TSCs, which is consistent with the expression of SARS-CoV-2 entry host factors, ACE2 (angiotensin-converting enzyme 2) and TMPRSS2 (transmembrane cellular serine protease) in these cells. In addition, both TSC-derived EVT and STB infected with SARS-CoV-2 elicited an interferon-mediated innate immune response. Combined, these results suggest that placenta-derived TSCs are a robust in vitro model to investigate the effect of SARS-CoV-2 infection in the trophoblast compartment of the early placenta and that SARS-CoV-2 infection in early gestation activates the innate immune response and inflammation pathways. Therefore, placental development could be adversely affected by early SARS-CoV-2 infection by directly infecting the developing differentiated trophoblast compartment, posing a higher risk for poor pregnancy outcomes.

Recent Advances in the Classification of Gynecological Tract Tumors: Updates From the 5th Edition of the World Health Organization "Blue Book".

CONTEXT.­: The World Health Organization Classification of Tumours: Female Genital Tract Tumors, 5th edition, published in September 2020, comes 6 years after the 4th edition, and reflects the monumental leaps made in knowledge about the biology of gynecological tumors. Major changes include revised criteria for the assignment of the site of origin of ovarian and fallopian tube tumors, a revision in the classification of squamous and glandular lesions of the lower genital tract based on human papillomavirus association, and an entire chapter devoted to genetic tumor syndromes. This article highlights the changes in the 5th edition relative to the 4th edition, with a focus on areas of value to routine clinical practice. OBJECTIVE.­: To provide a comprehensive update on the World Health Organization classification of gynecological tumors, highlighting in particular updated diagnostic criteria and terminology. DATA SOURCES.­: The 4th and 5th editions of the World Health Organization Classification of Tumours. CONCLUSIONS.­: The World Health Organization has made several changes in the 5th edition of the update on female genital tumors. Awareness of the changes is needed for pathologists' translation into contemporary practice.

Development of Adenovirus Containing Liposomes Produced by Extrusion vs. Homogenization: A Comparison for Scale-Up Purposes.

Adenovirus (Ad) is a widely studied viral vector for cancer therapy as it can be engineered to cause selective lysis of cancer cells. However, Ad delivery is limited in treating cancers that do not have coxsackievirus and adenovirus receptors (CAR). To overcome this challenge, Ad-encapsulated liposomes were developed that enhance the delivery of Ads and increase therapeutic efficacy. Cationic empty liposomes were manufactured first, to which an anionic Ad were added, which resulted in encapsulated Ad liposomes through charge interaction. Optimization of the liposome formula was carried out with series of formulation variables experiments using an extrusion process, which is ideal for laboratory-scale small batches. Later, the optimized formulation was manufactured with a homogenization technique-A high shear rotor-stator blending, that is ideal for large-scale manufacturing and is in compliance with Good Manufacturing Practices (GMP). Comparative in vitro transduction, physicochemical characterization, long-term storage stability at different temperature conditions, and in vivo animal studies were performed. Ad encapsulated liposomes transduced CAR deficient cells 100-fold more efficiently than the unencapsulated Ad (p ≤ 0.0001) in vitro, and 4-fold higher in tumors injected in nude mice in vivo. Both extrusion and homogenization performed similarly-with equivalent in vitro and in vivo transduction efficiencies, physicochemical characterization, and long-term storage stability. Thus, two Ad encapsulated liposomes preparation methods used herein, i.e., extrusion vs. homogenization were equivalent in terms of enhanced Ad performance and long-term storage stability; this will, hopefully, facilitate translation to the clinic.

Human Leukocyte Antigens in Pregnancy and Preeclampsia.

Preeclampsia is a pregnancy-induced hypertensive disorder, the pathophysiology of which includes underlying maternal cardiovascular disease, deficient spiral artery remodeling during placenta development, and inflammatory immune responses at the maternal-fetal interface. Human leukocyte antigens (HLA) are major histocompatibility complex molecules essential for the recognition of foreign antigens that is central to immune defense against pathogens and critical determinants for the immune system discriminating between self and non-self tissues, such as in transplantation. Pregnancy represents a naturally existing "transplantation", where the maternal immune system must be immunologically tolerant to the developing fetus which is 50% allogeneic. It is then unsurprising that HLA also influence normal pregnancy and pregnancy complications including preeclampsia. Here we review the role of classical and non-classical HLA molecules in influencing normal physiologic function during pregnancy and describe the association of HLA with pathophysiology in preeclampsia.

Novel insights linking BRCA1-IRIS role in mammary gland development to formation of aggressive PABCs: the case for longer breastfeeding.

Pregnancy-associated breast cancer (PABC) is diagnosed during or shortly after pregnancy. Although rare, PABC is a serious occurrence often of the triple negative (TNBC) subtype. Here we show progesterone, prolactin, and RANKL upregulate BRCA1-IRIS (IRIS) in separate and overlapping subpopulations of human mammary epithelial cell lines, which exacerbates the proliferation, survival, and the TNBC-like phenotype in them. Conversely, vitamin D3 reduces IRIS expression in TNBC cell lines, which attenuates growth, survival, and the TNBC-like phenotype in them. In the mouse, Brca1-Iris (Iris, mouse IRIS homolog) is expressed at low-level in nulliparous mice, increases ~10-fold in pregnant/lactating mice, to completely disappear in involuting mice, and reappears at low-level in regressed glands. Mice underwent 3 constitutive pregnancies followed by a forced involution (after 5 days of lactation) contained ~10-fold higher Iris in their mammary glands compared to those underwent physiological involution (after 21 days of lactation). While protein extracts from lactating glands promote proliferation in IRISlow and IRIS overexpressing (IRISOE) cells, extracts from involuting glands promote apoptosis in IRISlow, and aneuploidy in IRISOE cells. In a cohort of breast cancer patients, lack of breastfeeding was associated with formation of chemotherapy resistant, metastatic IRISOE breast cancers. We propose that terminal differentiation triggered by long-term breastfeeding reduces IRIS expression in mammary cells allowing their elimination by the inflammatory microenvironment during physiological involution. No/short-term breastfeeding retains in the mammary gland IRISOE cells that thrive in the inflammatory microenvironment during forced involution to become precursors for aggressive breast cancers shortly after pregnancy.

PTEN Loss and ARID1A Mutation in an HPV-positive Metastatic Adenocarcinoma Diagnosed Almost 18 yr After an Intact Cone Excision for Endocervical Adenocarcinoma In Situ.

There have been previous reports of neoplasms with the morphology of endocervical adenocarcinoma in situ (AIS) that secondarily involve the ovaries, presumably through transtubal spread, with a smaller subset metastasizing to distant sites. These ovarian metastases have been discovered up to 7 yr postexcision of the endocervical lesion, consistent with the known potential for overtly invasive cervical carcinomas to recur late after primary curative management. Herein, we present a case of a premenopausal woman with a pelvic mass classified as metastatic human papillomavirus (HPV)-associated endocervical adenocarcinoma (p16-block immunoreactive, high-risk HPV positive by in situ hybridization with PTEN loss, ARID1A, and PBRM1 mutations detected by qualitative next-generation sequencing), identified 17.7 yr (212 mo) after a fertility-sparing cone excision with negative margins for endocervical AIS [HPV-associated, p16-block immunoreactive; PTEN, and BAF250a (ARID1a) expression retained]. Our case highlights: (1) the potential for a subset of lesions with the morphology of AIS to metastasize, and the extraordinarily long timeframe (almost 18 y, the longest reported to date) during which metastases may still be identified; (2) alterations in PTEN and ARID1A may play a role in the progression of a subset of endocervical carcinomas; and (3) the need for studies to evaluate the utility of incorporating ovarian/pelvic imaging into surveillance protocols following fertility-sparing excisions or ovarian-preserving hysterectomies, during the management of endocervical adenocarcinomas, as well as the need to counsel patients about the small but real risk of delayed discovery of ovarian metastases following fertility-preserving surgeries for AIS.

Systemic AA Amyloidosis Associated With Intravenous Injection of Oral Prescription Opioids-An Autopsy Case Report.

ABSTRACT: There are reports of AA amyloidosis associated with intravenous and/or subcutaneous injection of street drugs, such as heroin and cocaine. Most reports describe patients with substance use disorder, renal amyloidosis and concurrent viral infections, such as hepatitis and/or human immunodeficiency virus. Herein, we present a case of systemic AA amyloidosis and sepsis in a 34-year-old woman with a history of intravenous injection of oral prescription medications (as evidenced by excipient lung disease) who had no known history of human immunodeficiency virus nor of hepatitis B or C. Our case shows the broader spectrum of pathology that can occur with the misuse of prescription medications.

Independent Validation of Tumor Budding Activity and Cell Nest Size as Determinants of Patient Outcome in Squamous Cell Carcinoma of the Uterine Cervix.

A novel 3-tiered grading system that combines tumor budding activity and cell nest size has been found to be highly prognostic in squamous cell carcinomas (SCCs) of various sites, including lung, oral cavity, larynx, hypopharynx, and esophagus. A similar grading system has recently been proposed for SCC of the uterine cervix. In this study, we appraise this grading system in an institutional cohort of cervical SCC to assess its prognostic value in an independent dataset. Our study cohort consisted of 94 consecutive, surgically excised, neoadjuvant therapy-naive cases of SCC of the uterine cervix, stage pT1b or higher. Tumor budding activity and cell nest size were scored on each case, the sum of which formed the basis for assigning a grade in the 3-tiered grading system hereafter referred to as the "tumor budding/nest size" (TBNS) system. As individual variables, both high tumor budding and small nest size were each associated with reduced overall survival (OS), disease-specific survival, and disease-free survival. The full TBNS system was associated with decreased OS, disease-specific survival, and disease-free survival independent of patient age, pathologic stage, and regional lymph node status. TBNS grades 1, 2, and 3 subgroups were clearly distinguishable on multivariate analyses (hazard ratio for OS of 2.06 [95% confidence interval: 0.5-8.42] for grade 2 and 4.58 [95% confidence interval: 1.24-16.87] for grade 3 tumors, relative to their grade 1 counterparts [P=0.035]). Higher grade tumors in the TBNS system were significantly correlated with advanced pathologic stage and lymph node metastasis (P=0.044 and 0.04, respectively). Among the other, potentially prognostic factors, higher pathologic stage, and lymph node metastasis were associated with decreased OS (P<0.001 and 0.004, respectively), whereas keratinization, nuclear size, mitotic count, and World Health Organization (WHO) grade were not. In conclusion, the proposed TBNS grading system is an excellent prognostic indicator that may potentially provide information that is useful in clinical decision-making. Our findings validate the previous study that proposed this system for prognostically stratifying cervical SCC patients. If further confirmed, consideration should be given to routinely adding a TBNS grade to pathologic descriptions of cervical SCC.

Disseminated Endometriosis and Low-Grade Endometrioid Stromal Sarcoma in a Patient with a History of Uterine Morcellation for Adenomyosis.

Morcellation of benign uterine tumors allows for removal of the tumors via minimally invasive laparoscopic procedures. However, in rare cases, morcellation has been associated with upstaging of unexpected malignancies. Morcellation has also been associated with dissemination of benign pathologic processes such as endometriosis and leiomyomas. Endometrial stromal sarcoma typically arises in the uterine cavity, although cases of extrauterine endometrioid stromal sarcoma arising out of foci of endometriosis have been reported. Dissemination of endometrial stromal sarcomas can be an unintended consequence of morcellation procedures, as can dissemination of endometriosis, from which endometrioid stromal sarcomas can arise. Herein, we report a case of a 55-year-old woman who was found to have disseminated endometriosis and low-grade endometrioid stromal sarcoma, with bowel and liver parenchymal metastasis, 7 years after undergoing supracervical hysterectomy with unconfined uterine morcellation for adenomyosis. Our case highlights the potential for malignant transformation of disseminated adenomyosis/endometriosis and the importance of patient counseling and shared decision-making prior to morcellation procedures.

Modified Plasma-Thrombin Method of Cell Block Preparation for Fine-Needle Aspiration Biopsies in Resource-Limited Settings.

OBJECTIVES: The plasma-thrombin method is commonly used to make cell blocks from fine-needle aspiration (FNA) samples but requires centrifugation. We describe a modification to this method that does not require centrifugation for use in resource-limited settings. METHODS: Pooled fresh plasma is aliquoted into 2-mL Eppendorf tubes and the FNA sample directly rinsed into the plasma. Two drops of reconstituted thrombin are added and gently mixed. A cell clot is transferred to a tissue bag, fixed in formalin, and processed. This method was applied to FNA samples from 44 patients presenting to the Mbarara University of Science and Technology FNA clinic. RESULTS: The cell blocks were less cellular than the smears but contained adequate material to confirm morphologic impression or perform immunocytochemistry in 36 of 44 cases (82% adequacy rate). CONCLUSIONS: The modified plasma-thrombin method is a reliable cell block preparation method that can be easily applied in resource-limited settings.

YWHAE Rearrangement in a Purely Conventional Low-grade Endometrial Stromal Sarcoma that Transformed Over Time to High-grade Sarcoma: Importance of Molecular Testing.

Low and high-grade endometrial stromal sarcomas (ESS) can be distinguished on a morphologic basis. Low-grade ESS is composed of oval cells that resemble normal proliferative-phase endometrial stroma, while the well-known high-grade ESS is composed of round cells growing in nests separated by delicate sinusoidal vasculature. Recurrent JAZF1 rearrangements have been reported to be most frequent in low-grade stromal sarcomas (up to 60%), while YWHAE rearrangements are characteristic of high-grade ESS. Herein, we report a case of a 45-yr-old woman with stage IA typical low-grade ESS who developed multiple abdominopelvic recurrences and lung metastases 15 mo after her primary tumor was resected. The unusual morphology (without high-grade areas) as well as the aggressive behavior of the tumor prompted molecular testing which showed YWHAE rearrangement in her abdominopelvic recurrence and her primary tumor. Five years after her primary tumor was resected, she developed scalp metastases with a typical morphology of a high-grade ESS associated with t(10;17) and died of her disease. Our case highlights the potential value of molecular testing in all low-grade ESS at time of initial diagnosis to stratify patients at higher risk for developing high-grade ESS with the goal of offering closer follow-up for early detection and treatment if transformation occurs.

Utility of Flow Cytometry in Diagnosing Hematologic Malignancy in Tonsillar Tissue.

OBJECTIVE: Tonsil surgical biopsy or excision is a very common procedure. However, there exist no consensus guidelines for the pathologic handling of tonsil specimens; gross and/or microscopic evaluation may be used. Diagnosis of tonsillar hematologic malignancy requires histology, immunohistochemistry and/or flow cytometry. Data regarding the utility of flow cytometry in tonsillar tissues are limited. We assessed our experience with flow cytometry for tonsil diagnosis with regard to accuracy and use patterns at a tertiary academic medical center. METHODS: We retrospectively analyzed all surgically biopsied or excised tonsil specimens that underwent flow cytometry evaluation from August 2011 to March 2014. Patient clinical information, intraoperative frozen section, histology, immunohistochemistry, and flow cytometry diagnoses were recorded. RESULTS: The study included 154 tonsil specimens from 89 females and 65 males. Patients averaged 27.4 years old (range 2-87 years); 73 were pediatric. Both histology and flow cytometry were benign for 148 patients (96.1%). Hematolymphoid malignancy was diagnosed in 6 adults by histology/immunohistochemistry: diffuse large B-cell lymphoma (2), small B-cell lymphoma (2), concomitant follicular lymphoma and histiocytic sarcoma (1), and extraosseous plasmacytoma (1). Flow cytometry identified abnormal populations in 5 of 6 cases, and detected clonal populations in 2 reactive follicular hyperplasia cases. CONCLUSION: Tonsillar hematolymphoid malignancy is uncommon, and flow cytometry was less accurate than histology/immunohistochemistry for its diagnosis. Despite the rarity of tonsillar lymphoma in children, nearly half of study patients were pediatric. Intraoperative frozen section diagnosis showed excellent sensitivity for malignancy, and could be used to effectively triage cases for flow cytometry evaluation.