Neoadjuvant chemotherapy for high-grade serous ovarian cancer: radiologic-pathologic correlation of response assessment and predictors of progression.

PURPOSE: Neoadjuvant chemotherapy is often administered for high-grade serous ovarian carcinoma (HGSC) prior to cytoreductive surgery. We evaluated treatment response by CT (simplified peritoneal carcinomatosis index [S-PCI]), pathology (chemotherapy response score [CRS]), laboratory markers (serum CA-125), and surgical outcomes, to identify predictors of disease-free survival. METHODS: For this retrospective, HIPAA-compliant, IRB-approved study, we identified 396 women with HGSC receiving neoadjuvant chemotherapy between 2010 and 2019. Two hundred and ninety-nine patients were excluded (surgery not performed; imaging/pathology unavailable). Pre- and post-treatment abdominopelvic CTs were assigned CT S-PCI scores 0-24 (higher score indicating more tumor). Specimens were assigned CRS of 1-3 (minimal to complete response). Clinical data were obtained via chart review. Univariate, multivariate, and survival analyses were performed. RESULTS: Ninety-seven women were studied, with mean age of 65 years ± 10. Interreader agreement was good to excellent for CT S-PCI scores (ICC 0.64-0.77). Despite a significant decrease in CT S-PCI scores after treatment (p < 0.001), mean decrease in CT S-PCI did not differ significantly among CRS categories (p = 0.20) or between patients who were optimally versus suboptimally debulked (p = 0.29). In a survival analysis, lower CRS (more viable tumor) was associated with shorter time to progression (p < 0.001). A joint Cox proportional-hazard models showed that only residual pathologic disease (CRS 1/2) (HR 4.19; p < 0.001) and change in CA-125 (HR 1.79; p = 0.01) predicted progression. CONCLUSION: HGSC response to neoadjuvant therapy by CT S-PCI did not predict pathologic CRS score, optimal debulking, or progression, revealing discordance between imaging, pathologic, biochemical, and surgical assessments of tumor response.

Solitary Fibrous Tumor of Breast and Axilla: Clinicopathological Profile of Five Tumors With Comparison of Risk Stratification Models.

Introduction: Solitary fibrous tumor (SFT) is a fibroblastic tumor with malignant potential that is underpinned by a recurrent inv12(q13q13)-derived NAB2::STAT6 fusion. Breast and axilla are uncommon locations for this entity. Methods: Records of two academic institutions were electronically searched for breast and axillary SFTs. Clinical and pathologic data were reviewed. Literature review for breast or axillary SFTs was performed. Present study and previously reported tumors were stratified using five SFT risk models: original and modified Demicco metastatic risk, Salas local recurrence risk, Salas metastatic risk, and Thompson local recurrence risk. Results: Five patients with breast or axillary SFT were identified. Median age was 49 years, and median follow-up (available for four patients) was 82 months. Three patients showed no evidence of disease, and one developed recurrence. Literature review identified 58 patients with breast or axillary SFT. Median age was 54 years, and median follow-up (available for 35 patients) was 24 months. Thirty-one patients showed no evidence of disease, three developed recurrence, and one developed metastasis. Original and modified Demicco models and Thompson model showed the highest sensitivity; original and modified Demicco models and Salas metastatic risk model demonstrated the highest specificity. Kaplan-Meier models were used to assess recurrence-free probability (RFP). Original and modified Demicco models predicted RFP when stratified by "low risk" and "moderate/intermediate and high risk" tumor, though sample size was small. Conclusions: While many SFTs of breast and axilla remain indolent, a subset may develop recurrence and rarely metastasize. The modified Demicco risk model demonstrated optimal performance characteristics.

Nipple Adenoma: Clinicopathologic Characterization of 50 Cases.

Nipple adenoma (NA) is a rare, benign proliferation of the nipple ducts. It may be clinically mistaken for Paget disease or squamous cell carcinoma; thus, microscopic evaluation is paramount. A large case series of NA has not been undertaken since the 1980s. Therefore, we undertook this study to evaluate the clinicopathologic characteristics of NA, emphasizing differential diagnoses and follow-up data. We retrieved 50 cases from our in-house archives or consultation files between 2003 and 2022. Available slides were reviewed, and clinical data and follow-up information were obtained. Cases must have exhibited a dense ductal proliferation in the breast tissue with proximity to the nipple epidermis. All patients were women; median age was 56 years. In all, 68% of patients were symptomatic; 53% demonstrated a skin growth. Overall, 67% were excised completely, either primarily (33%) or via re-excision after biopsy (33%). Four histologic patterns were noted: adenosis (dense proliferation of small-to-medium ducts); large duct (medium-to-large caliber ducts); papillary-like (frond-like architecture with branching, slit-like lumens); and pseudoinfiltrative (ducts squished and distorted by dense stromal fibrosis). Follow-up in 44 patients (88%) with a median time of 66 months showed no evidence of recurrence. NA demonstrates a wide spectrum of histopathologic variation. Subtyping of this entity is unlikely to be clinically relevant. Differentiation from invasive carcinoma or other histologic mimics (syringocystadenoma papilliferum, syringomatous adenoma) may be difficult. Simple excision is curative, and recurrence is rare. A definitive link to invasive carcinoma has not been established.

Low-grade adenosquamous carcinoma of the breast: a clinical, morphological and immunohistochemical analysis of 25 patients.

AIMS: Due to its rarity and non-specific clinical and pathological features, low-grade adenosquamous carcinoma (LGASC) of the breast continues to pose diagnostic challenges. Unlike other triple-negative breast carcinomas, LGASC tends to have an indolent clinical behaviour. It is essential to recognise this lesion for accurate diagnosis and appropriate management. METHODS AND RESULTS: Twenty-five cases of LGASC were identified in our archives and collaborating institutes. Cases of LGASC with dominant coexisting other type carcinomas were excluded. We studied the clinical presentation, morphological features, patterns of the commonly used immunohistochemical stains and follow-up. In our cohort, LGASC was commonly located at the outer aspect of the breast and associated with intraductal papilloma. The morphology of LGASC is characterised by infiltrating small glands and nests with variable squamous differentiation. We also found cuffing desmoplastic (fibrolamellar) stromal change in 75% of patients and peripheral lymphocytic aggregates in 87.5% of patients. P63 and smooth muscle myosin (SMM) were the most common myoepithelial markers used to assist in diagnosis. P63 often stained peripheral tumour cells surrounding invasive glands (circumferential staining in 80% of the cases), mimicking myoepithelial cells. It also stained the small nests with squamous differentiation. However, SMM was negative in 63% of the cases. The vast majority of our cases were triple-negative; only a few had focal and weak expressions of ER and PR. One patient who did not have excision developed lymph node metastasis. Most patients underwent excision or mastectomy with negative margins as surgical treatment; there were no recurrences or metastases in these patients with clinical follow-ups up to 108 months. CONCLUSIONS: LGASC has some unique, although not entirely specific, morphological features and immunohistochemical staining patterns. Fibrolamellar stromal change, peripheral lymphocytic aggregates and variable staining of p63 and SMM are valuable features to facilitate the diagnosis.

Unusual Ovarian Tumors With Endometrioid Proliferations Co-Expressing Estrogen Receptor and CDX-2 Arising in Cystadenofibromatous Background: Report of 3 Cases.

This report describes 3 cases of ovarian tumors with unusual glandular proliferations co-expressing estrogen receptor and CDX-2 by immunohistochemistry set in cystadenofibromatous background. Targeted next-generation sequencing was performed on the cyst lining epithelium and glandular proliferations for all cases; CTNNB1 mutations were detected in the glandular proliferations of all neoplasms. The cyst lining of case 1 demonstrated a different CTNNB1 mutation from the matched glandular proliferation. No mutations were detected in the cyst lining from case 2. The cyst lining and glandular proliferation for case 3 harbored identical ATM and PIK3CA mutations with an additional CTNNB1 mutation in the glandular proliferation. To our knowledge, this is the first reported series of endometrioid proliferations with co-expression of estrogen receptor and CDX-2 in cystadenofibromatous background.

Inhibition of Tumor Microenvironment Cytokine Signaling Sensitizes Ovarian Cancer Cells to Antiestrogen Therapy.

Antiestrogen therapy (AET) is an alternative to cytotoxic chemotherapy for recurrent ovarian cancer, yet the often short duration of response suggests mechanisms of resistance. We previously demonstrated that tumor microenvironment interleukin-6/leukemia inhibitory factor (IL6/LIF) cytokines induce tumor cell JAK-STAT signaling to promote cancer growth. Crosstalk between estrogen signaling and cytokine signaling has been reported. Therefore, we sought to characterize the impact of IL6/LIF signaling on estrogen signaling in epithelial ovarian cancer and investigate the efficacy of combination therapy. We first assessed patient tumors for cytokine expression and compared it with response to AET to determine clinical relevance. In vitro, we determined the effect of IL6/LIF on estrogen receptor expression and signaling. Cell viability assays were used to determine the efficacy and potential synergy of cytokine blockade and AET. We then extended studies to animal models, incorporating patient-derived stromal cells. Our results demonstrated shorter progression-free interval on AET in patients with stromal IL6/LIF expression. In vitro, IL6/LIF increased tumor cell estrogen receptor expression and signaling, and combination cytokine blockade and AET resulted in synergistic inhibition of tumor cell growth. The anticancer effect was verified in a mouse model. In conclusion, due to crosstalk between IL6/LIF cytokine signaling and estrogen signaling, dual blockade is a potential new treatment approach for ovarian cancer.

p53/CK17 Dual Stain Improves Accuracy of Distinction Between Differentiated Vulvar Intraepithelial Neoplasia and Its Mimics.

Accurate diagnosis of differentiated vulvar intraepithelial neoplasia (dVIN) is challenging, in part due to the sometimes subtle nature of its atypia. Many dVIN lesions demonstrate aberrant p53 staining; however, staining patterns overlap between dVIN and benign/reactive entities. We evaluate a p53/CK17 dual stain in an initial cohort of dVIN (n=30), benign vulvar skin (n=5), lichen sclerosus (LS, n=10), lichen simplex chronicus (LSC, n=10), and pseudoepitheliomatous hyperplasia (PEH, n=10). In the initial cohort, aberrant p53 staining was seen only in dVIN (50%, 15/30). Equivocal p53 staining patterns were seen in dVIN (37%, 11/30), LS (50%, 5/10), LSC (40%, 4/10), and PEH (40%, 4/10). All 30 dVIN cases were positive for CK17 (strong partial-thickness or full-thickness staining), but positive CK17 staining was also seen in LS (70%, 7/10), LSC (50%, 5/10), and PEH (100%, 10/10). In the initial cohort, the combination of aberrant p53 and positive CK17 was seen only for dVIN (50%, 15/30). Forty cases of LS with known follow-up (20 with progression to dVIN, 20 without) were stained to assess prognostic value. Three LS cases showed aberrant p53 staining with CK17 positivity; all progressed to dVIN. Equivocal p53 staining and CK17 positivity were seen in cases with and without progression. The p53/CK17 dual stain is more diagnostically useful than either stain alone. Negative/focal staining for CK17 argues against a diagnosis of dVIN, while aberrant p53 staining with CK17 positivity strongly supports the diagnosis.

Management of early stage HER2 positive breast cancer and increased implementation of axillary imaging to improve identification of nodal metastasis.

BACKGROUND AND OBJECTIVES: Given the significant benefit of targeted therapies for HER2+ breast cancer patients in both the neoadjuvant and adjuvant settings, it is critical to identify all eligible patients for these treatments. We sought to investigate cT1cN0 HER2+ patients to determine the rate of postsurgical nodal positivity, and to identify presurgical factors associated with nodal positivity. We hypothesize there is a subset of underdiagnosed HER2+ patients who would benefit from preoperative axillary imaging and inclusion in neoadjuvant chemotherapy regimens. METHODS: We performed a 10-year retrospective analysis of T1 HER2+ breast cancer patients. Clinicopathologic characteristics were evaluated based on surgical nodal data. RESULTS: We identified 38 patients with cT1cN0 HER2+ cancer. Of this cohort, 24% had positive lymph nodes on final pathology. High tumor grade (p = 0.035) on core needle biopsy and the presence of lymphovascular invasion (p = 0.0036) were associated with an increased likelihood of lymph node positivity. The majority (66%) of lymph node positive patients were clinically T1c. CONCLUSIONS: We identified a 24% nodal positivity rate in clinically node negative T1 HER2+ breast cancer patients. In particular, HER2+ patients with high-grade T1c cancers should undergo preoperative diagnostic axillary imaging to expand potential benefit from targeted therapies.

Surface prostatic metaplasia, transitional cell metaplasia and superficial clusters of small basophilic cells in the uterine cervix: prevalence in gender-affirming hysterectomies and comparison with benign hysterectomies from cisgender women.

AIMS: As gender-affirming surgery is becoming more common, it is important for pathologists to recognize potential benign findings to avoid misinterpretation. Cervical transitional cell metaplasia and superficial clusters of small basophilic cells have been described in the context of gender-affirming testosterone therapy; these findings may be misdiagnosed as high-grade squamous intraepithelial lesions or endometrial cells on Pap smears. Prostatic metaplasia has been reported in the surface squamous epithelium of the vagina and the uterine cervix in individuals undergoing gender-affirming androgen therapy; this finding is often associated with NKX3.1-positive basal keratinocytes. The aim of this study was to assess the morphological and immunohistochemical features of the uterine cervix in gender-affirming hysterectomies in comparison with benign hysterectomies from cisgender women. METHODS AND RESULTS: We assessed the morphological and immunohistochemical features of the uterine cervix in 49 gender-affirming hysterectomies as compared with 57 hysterectomies from cisgender patients to establish the relative prevalences of surface prostatic metaplasia, NKX3.1-positive basal keratinocytes, transitional cell metaplasia, and small basophilic cells in the cervical squamous epithelium. The cervical tissue from the gender-affirming therapy cohort showed significantly higher prevalences of NKX3.1-positive basal keratinocytes (86% versus 1.8%), transitional cell metaplasia (80% versus 3.5%), superficial clusters of small basophilic cells (67% versus 7%), and surface prostatic metaplasia (43% versus 3.5%). CONCLUSION: NKX3.1-positive basal keratinocytes, transitional cell metaplasia, small basophilic cells and surface prostatic metaplasia are all more prevalent in the cervices of individuals receiving gender-affirming testosterone therapy; awareness of this fact allows pathologists to avoid the overdiagnosis of dysplasia or the recommendation of unnecessary follow-up procedures.

Quantitative Image Analysis as an Adjunct to Manual Scoring of ER, PgR, and HER2 in Invasive Breast Carcinoma.

OBJECTIVES: Biomarker expression evaluation for estrogen receptor (ER), progesterone receptor (PgR), and human epidermal growth factor receptor 2 (HER2) is an essential prognostic and predictive parameter for breast cancer and critical for guiding hormonal and neoadjuvant therapy. This study compared quantitative image analysis (QIA) with pathologists' scoring for ER, PgR, and HER2. METHODS: A retrospective analysis was undertaken of 1,367 invasive breast carcinomas, including all histopathology subtypes, for which ER, PgR, and HER2 were analyzed by manual scoring and QIA. The resulting scores were compared, and in a subset of HER2 cases (n = 373, 26%), scores were correlated with available fluorescence in situ hybridization (FISH) results. RESULTS: Concordance between QIA and manual scores for ER, PgR, and HER2 was 93%, 96%, and 90%, respectively. Discordant cases had low positive scores (1%-10%) for ER (n = 33), were due to nonrepresentative region selection (eg, ductal carcinoma in situ) or tumor heterogeneity for PgR (n = 43), and were of one-step difference (negative to equivocal, equivocal to positive, or vice versa) for HER2 (n = 90). Among HER2 cases where FISH results were available, only four (1.0%) showed discordant QIA and FISH results. CONCLUSIONS: QIA is a computer-aided diagnostic support tool for pathologists. It significantly improves ER, PgR, and HER2 scoring standardization. QIA demonstrated excellent concordance with pathologists' scores. To avoid pitfalls, pathologist oversight of representative region selection is recommended.

An extrauterine extensively metastatic epithelioid trophoblastic tumor responsive to pembrolizumab.

We report a case of extrauterine epithelioid trophoblastic tumor (ETT)-the rarest variant of gestational trophoblastic tumor-that has been stable on nearly two years of pembrolizumab treatment. A 47-year-old gravida 2, para 2 who underwent a prophylactic bilateral salpingo-oophorectomy nine years prior and bilateral mastectomy five years prior in the setting of a strong family history of breast and ovarian cancer with no genetic testing performed, presented to an outside clinic with recurrent respiratory infections without resolution despite antibiotics. Radiology and pathology testing confirmed the ETT diagnosis, including a second opinion from the John I. Brewer Trophoblastic Disease Center of Northwestern University's Feinberg School of Medicine, and the patient was started on a chemotherapy regimen of etoposide, methotrexate, actinomycin-D, etoposide, and cisplatin for seven cycles, with partial improvement in her disease. After PD-L1 testing showed the tumor had > 5% PD-L1 positivity, she initiated pembrolizumab in April 2019. CT imaging after three months revealed decreased lung, abdominal, and pelvic disease and she was continued on pembrolizumab. As of December 2020, she had completed 29 cycles of pembrolizumab, with a plan for her to continue treatment indefinitely given her decreased, but persistent, disease. Our findings suggest pembrolizumab is a reasonable option for treatment of patients with significant PD-L1 positivity on testing of the tumor.

Patterns of SATB2 and p16 reactivity aid in the distinction of atypical polypoid adenomyoma from myoinvasive endometrioid carcinoma and benign adenomyomatous polyp on endometrial sampling.

AIMS: Atypical polypoid adenomyoma (APAM) is an uncommon uterine lesion composed of complex endometrioid glands with frequent squamous morular metaplasia and fibromuscular stroma. On endometrial curettage, biopsy or polypectomy specimens, the admixture of endometrioid glands and smooth muscle raises the differential diagnosis of myoinvasive endometrioid carcinoma. Reproductive-age APAM patients may opt for fertility preservation, whereas myoinvasive carcinoma is treated surgically. One previous study reported an incidental finding that the stroma of APAM, in contrast to that of other polypoid lesions, was SATB2-positive. APAM has also been reported to show increased stromal p16 staining. We aimed to assess whether SATB2 and p16 are useful stains for the distinction of APAM from myoinvasive carcinoma and benign adenomyomatous polyps. METHODS AND RESULTS: Cases of 'atypical polypoid adenomyoma' (n = 32), 'adenomyomatous polyp' (n = 39) and 'myoinvasive endometrioid carcinoma' (n = 30) were identified. Morphological features were assessed, along with the intensity and extent of SATB2 and p16 staining in the stromal component of each lesion. SATB2 expression was seen in the stromal components of 30 of 32 (94%) APAMs, versus none of 39 (0%) benign adenomyomatous polyps and five of 30 (17%) myoinvasive endometrioid carcinomas. Stromal p16 expression was seen in 31 of 31 (100%) APAMs, versus 20 of 39 (51%) benign adenomyomatous polyps and 12 of 30 (40%) myoinvasive endometrioid carcinomas. CONCLUSIONS: Patchy to diffuse SATB2 and block-type p16 staining of fibromuscular stroma separating atypical endometrioid glands is more consistent with APAM than with myoinvasive endometrioid carcinoma. These stains are potentially useful adjuncts to careful morphological evaluation of endometrial biopsies/curettings.

Molecular characterization of uterine and ovarian tumors with mixed epithelial and germ cell features confirms frequent somatic derivation.

Ovarian germ cell tumors, including yolk sac tumors, are most commonly diagnosed in children and young women. Most so-called yolk sac tumors reported in women >35 years old have been associated with an epithelial proliferation (endometriosis or carcinoma). Here, we describe eight cases clinically diagnosed as uterine or ovarian germ cell tumors in women >35 years old. In addition to routine morphologic examination and immunohistochemical evaluation, we present data from targeted next-generation sequencing (NGS) and isochromosome (12p) fluorescence in situ hybridization (FISH). We identified two groups of tumors with mixed germ cell and epithelial features: (1) tumors with background endometriosis and endometrioid carcinoma-like mutations (PTEN, PIK3CA, FGFR2, and CTNNB1), and (2) high-grade morphology, presumptive presence of isochromosome (12p) by FISH, and TP53 or PIK3CA mutations. These findings support the notion that the "germ cell tumor" component of these tumors is often somatically derived. Two tumors in our cohort were from premenopausal women; one showed no detectable mutations by NGS (suggestive of germ cell derivation), whereas the other showed PIK3CA, PTEN, and CTNNB1 mutations (suggestive of somatic derivation). Accurate classification of these tumors is likely important for selection of appropriate chemotherapy.

Radiologic-Histopathologic Correlation of Transvaginal US and Risk-reducing Salpingo-oophorectomy for Women at High Risk for Tubo-ovarian Carcinoma.

Purpose: To examine radiologic-histopathologic correlation and the diagnostic performance of transvaginal US prior to risk-reducing salpingo-oophorectomy (RRSO) in women at high risk for tubo-ovarian carcinoma (TOC). Materials and Methods: This retrospective study included 147 women (mean age, 49 years; age range, 28-75 years) at high risk for TOC who underwent transvaginal US within 6 months of planned RRSO between May 1, 2007, and March 14, 2018. Histopathologic results were reviewed. Fellowship-trained abdominal radiologists reinterpreted transvaginal US findings by using standardized descriptors. Descriptive statistical analysis and multiple logistic regression were performed. Results: Of the 147 women, 136 had mutations in BRCA1, BRCA2, Lynch syndrome, BRIP1, and RAD51D genes, and 11 had a family history of TOC. Histopathologic reports showed 130 (88.4%) benign nonneoplastic results, 10 (6.8%) benign neoplasms, five (3.4%) malignant neoplasms, and two (1.4%) isolated p53 signature lesions. Transvaginal US results showed benign findings in 95 (64.6%) women and abnormal findings in 11 (7.5%) women; one or both ovaries were not visualized in 41 (27.9%) women. Hydrosalpinx was absent in all TOC and p53 signature lesions at transvaginal US. Transvaginal US had 20% sensitivity (one of five), 93% specificity (132 of 142), 9% positive predictive value (one of 11), and 97% negative predictive value (132 of 136) for TOC. Cancer was detected in one of five women at transvaginal US, and three of five false-negative lesions were microscopic or very small. Conclusion: Preoperative transvaginal US had low sensitivity for detecting TOC in women at high risk for TOC. Clinically relevant precursors and early cancers were too small to be detected.Keywords: Genital/Reproductive, UltrasoundSupplemental material is available for this article.© RSNA, 2020.

Cellular Spindled Histiocytic Pseudotumor: A Benign Mimic of Spindle Cell Neoplasia of the Breast.

CONTEXT.­: Cellular spindled histiocytic pseudotumor (CSHPT) is an exuberant, dense histiocytic proliferation seen in the setting of mammary fat necrosis. CSHPT has a broad histologic differential diagnosis, including benign, malignant, and inflammatory etiologies. OBJECTIVES.­: To highlight the most important histologic and immunohistochemical findings of CSHPT and provide comparisons to entities within the broad differential diagnosis. DATA SOURCES.­: Recently published literature regarding CSHPT and other diagnostic considerations. CONCLUSIONS.­: CSHPT is a benign histiocytic proliferation with a broad differential diagnosis, for which comprehensive ancillary studies may be required to exclude malignant and infectious entities.

Multiclonality and Marked Branched Evolution of Low-Grade Endometrioid Endometrial Carcinoma.

The molecular events driving low-grade endometrioid endometrial carcinoma (LGEC) development-like in many cancers-are incompletely understood. Hence, here we performed multiregion, comprehensive somatic molecular profiling of routinely processed formalin-fixed, paraffin-embedded (FFPE) material from 13 cases of LGEC totaling 64 minute, spatially defined cell populations ranging from presumed precursor lesions through invasive LGEC. Shared driving PTEN, PIK3R1, or PIK3CA mutations support clonal origin of the samples in each case, except for two cases with two clonally distinct neoplastic populations, consistent with unexpected multiclonality in LGEC development. Although substantial heterogeneity in driving somatic alterations was present across populations in nearly all cases, these alterations were usually clonal in a given population, supporting continued selection and clonal sweeping of driving alterations in populations with both precursor and LGEC histology. Importantly, CTNNB1 mutational status, which has been proposed as both prognostic and predictive in LGEC, was frequently heterogeneous and subclonal, occurring both exclusively in precursor or cancer populations in different cases. Whole-transcriptome profiling of coisolated RNA from 12 lesions (from 5 cases) was robust and confirmed histologic and molecular heterogeneity, including activated Wnt signaling in CTNNB1-mutant versus wild-type populations. Taken together, we demonstrate clinically relevant multiclonality and intratumoral heterogeneity during LGEC development with important implications for diagnosis, prognosis, and therapeutic prediction. More broadly, our methodology is broadly scalable to enable high-throughput genomic and transcriptomic characterization of precursor and invasive cancer populations from routine FFPE specimens. IMPLICATIONS: Multiregion profiling of LGEC populations using a highly scalable approach demonstrates clinically relevant multiclonality and intratumoral heterogeneity.

Implementing noninvasive follicular thyroid neoplasm with papillary-like nuclear features may potentially impact the risk of malignancy for thyroid nodules categorized as AUS/FLUS and FN/SFN.

BACKGROUND: Noninvasive encapsulated follicular variant of papillary thyroid carcinoma (PTC) has recently been reclassified as noninvasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP). Implementation of the new terminology may alter the implied risk of malignancy (ROM) across the six categories of The Bethesda System for Reporting Thyroid Cytopathology (TBSRTC). METHODS: The study cohort consisted of thyroid fine needle aspiration (FNA) cases which were assessed between January 2011 and June 2016 and led to surgical resections. For each case, patient demographics as well as cytologic and corresponding histologic diagnoses were recorded. The surgical specimens diagnosed as follicular variant of PTC (FVPTC) were re-reviewed to identify cases that met the diagnostic criteria for NIFTP. The ROM with and without exclusion of NIFTP from malignant categorization, as well as the relative change in ROM were calculated for individual categories of TBSRTC. RESULTS: A total of 908 FNA cases with surgical follow-up were retrieved and PTC was identified in 252 (27.8%) surgical specimens. Twenty-nine of 252 (11.5%) were initially classified as FVPTC, of which 17 (6.7%) were reclassified as NIFTP. The cytologic interpretations for the majority of NIFTP cases were atypia of undetermined significance/follicular lesion of undetermined significance (AUS/FLUS, n = 8) or follicular neoplasm/suspicious for neoplasm/(FN/SFN, n = 4). Excluding NIFTP from malignant categorization resulted in a relative decrease in ROM in AUS/FLUS (25.8%) and FN/SFN (22.3%) categories. CONCLUSION: Our institutional data demonstrates that eliminating NIFTP from malignant categorization may result in a reduction of the implied ROM for AUS/FLUS and FN/SFN categories.

Molecular Subtypes and Local-Regional Control of Breast Cancer.

In the era of personalized medicine, there has been significant progress regarding the molecular analysis of breast cancer subtypes. Research efforts have focused on how classification of subtypes could provide information on prognosis and influence treatment planning. Although much is known about the impact of different molecular subtypes on disease-specific survival, more recent studies have investigated the role of the different molecular subtypes on local-regional recurrence. This is an area of active study, and in recent years there has been significant progress. This article describes outcomes among disease subtypes to aid in optimal surgical decision-making to improve local-regional control.

MR Imaging-Pathologic Correlation in Ovarian Cancer.

There are many ovarian cancer subtypes, giving rise to a range of appearances at gross pathology and magnetic resonance (MR) imaging. Certain fundamental concepts at MR, arising from underlying tissue characteristics, can provide guidance to radiologists in suggesting a diagnosis. The ability of multiparametric MR to risk stratify ovarian masses can contribute substantially to clinical decision making and patient management.

Rare Presentation of Metastatic Cystic Trophoblastic Tumor in a Patient Without Prior Chemotherapy.

Cystic trophoblastic tumor (CTT) is a rare testicular germ cell tumor (GCT) predominantly seen in post-chemotherapy patients. It is prognostically similar to teratoma and requires no additional chemotherapy in the absence of a nonteratomatous GCT component. We report a case of metastatic CTT in a patient with primary testicular teratoma without prior chemotherapy. Retroperitoneal lymph node metastases contained teratoma, embryonal carcinoma, and CTT. The CTT was ß-hCG positive and SALL4 negative by immunohistochemistry (IHC). CTT can arise in metastatic testicular GCT in treatment naïve patients. An important differential diagnosis is choriocarcinoma due to treatment implications, and SALL4 IHC may help.