The Silva pattern-based classification for HPV-associated endocervical adenocarcinoma: A single institution concordance study of trainees and gynecologic pathologists.

The Silva pattern-based classification of HPV-associated endocervical adenocarcinoma has become an integral part of the histologic assessment of these tumors. Unfortunately, the Silva system reproducibility has had mixed results in past studies, and clinical practice still favors the FIGO stage assessment in directing therapeutic interventions for patients. In our study, we aimed to assess our institution's concordance including not only gynecologic pathologists, but also pathology trainees through a series of 69 cases. The grouped total kappa concordance from all participants was 0.439 (Moderate), with an overall trainee kappa of 0.417 (moderate) and an overall pathologist kappa of 0.460 (moderate). Perfect concordance among all 10 study participants was seen in 8/69 cases (11.6 %), corresponding to 5/22 Pattern A cases (22.7 %), 0/16 Pattern B cases (0 %), and 3/31 Pattern C cases (9.7 %), with similar findings between trainees and pathologists when compared within their own cohorts. Recurrence was identified in 2 Pattern A cases, indicating a potential issue with limited excisional specimens which may not fully appreciate the true biologic aggressiveness of the lesions.

From principles to practice: Implementation of entrustable professional activities (EPAs) for surgical pathology residency education in a large academic hospital.

Over the past decade, competency-based medical education (CBME) has gained momentum in the United States to develop trainees into independent and confident physicians by the end of their training. Entrustable professional activities (EPAs) are an established methodology for assessing trainee development through an outcomes-driven rather than a time-based model. While EPAs have been utilized as an assessment tool for CBME in Europe and Canada, their validation and implementation in some medical specialties has occurred more recently in the United States. Pediatrics was the first specialty in the US to conduct a large-scale UME-GME pilot. Pathology Residency EPAs were published in 2018; however, implementation in training programs has been slow. We have piloted EPAs in our residency program's surgical pathology rotation and propose a unique set of 4 surgical pathology EPAs to track trainee preparedness for independent practice.

Presurgical Oral Tamoxifen vs Transdermal 4-Hydroxytamoxifen in Women With Ductal Carcinoma In Situ: A Randomized Clinical Trial.

Importance: Oral tamoxifen citrate benefits women with ductal carcinoma in situ (DCIS), but concern about toxic effects has limited acceptance. Previous pilot studies have suggested transdermal 4-hydroxytamoxifen gel has equivalent antiproliferative efficacy to oral tamoxifen, with low systemic exposure. Objective: To demonstrate that 4-hydroxytamoxifen gel applied to the breast skin is noninferior to oral tamoxifen in its antiproliferative effect in DCIS lesions. Design, Setting, and Participants: This randomized, double-blind, phase 2 preoperative window trial was performed at multicenter breast surgery referral practices from May 31, 2017, to January 27, 2021. Among 408 women with estrogen receptor-positive DCIS who were approached, 120 consented and 100 initiated study treatment. The most common reasons for nonparticipation were surgical delay, disinterest in research, and concerns about toxic effects. Data were analyzed from January 26, 2021, to October 5, 2022. Intervention: Random assignment to oral tamoxifen citrate, 20 mg/d, and gel placebo or 4-hydroxytamoxifen gel, 2 mg/d per breast, and oral placebo, for 4 to 10 weeks, followed by DCIS resection. Main Outcomes and Measures: The primary end point was absolute change in DCIS Ki-67 labeling index (Ki67-LI). Secondary end points included 12-gene DCIS Score, breast tissue tamoxifen metabolite concentrations, tamoxifen-responsive plasma protein levels, and patient-reported symptoms. Noninferiority of Ki67-LI reduction by 4-hydroxytamoxifen gel was tested using analysis of covariance; within- and between-arm comparisons were performed with paired t tests for mean values or the Wilcoxon rank sum test for medians. Results: Of 90 participants completing treatment (mean [SD] age, 55 [11] years; 8 [8.9%] Asian, 16 [17.8%] Black, 8 [8.9%] Latina, and 53 [58.9%] White), 15 lacked residual DCIS in the surgical sample, leaving 75 evaluable for the primary end point analysis (40 in the oral tamoxifen group and 35 in the 4-hydroxytamoxifen gel group). Posttreatment Ki67-LI was 3.3% higher (80% CI, 2.1%-4.6%) in the 4-hydroxytamoxifen gel group compared with the oral tamoxifen group, exceeding the noninferiority margin (2.6%). The DCIS Score decreased more with oral tamoxifen treatment (-16 [95% CI, -22 to -9.4]) than with 4-hydroxytamoxifen gel (-1.8 [95% CI, -5.8 to 2.3]). The median 4-hydroxytamoxifen concentrations deep in the breast were nonsignificantly higher in the oral tamoxifen group (5.7 [IQR, 4.0-7.9] vs 3.8 [IQR, 1.3-7.9] ng/g), whereas endoxifen was abundant in the oral tamoxifen group and minimal in the 4-hydroxytamoxifen gel group (median, 13.0 [IQR, 8.9-20.6] vs 0.3 [IQR, 0-0.3] ng/g; P < .001). Oral tamoxifen caused expected adverse changes in plasma protein levels and vasomotor symptoms, with minimal changes in the transdermal group. Conclusions and Relevance: In this randomized clinical trial, antiproliferative noninferiority of 4-hydroxytamoxifen gel to oral tamoxifen was not confirmed, potentially owing to endoxifen exposure differences. New transdermal approaches must deliver higher drug quantities and/or include the most potent metabolites. Trial Registration: ClinicalTrials.gov Identifier: NCT02993159.

A novel 6-day cycle surgical pathology rotation improves resident satisfaction and maintains Accreditation Council for Graduate Medical Education (ACGME) milestone performance.

Surgical pathology residency training in the United States lags behind other specialties in quality control and graduated responsibility to train independent pathologists capable of seamlessly entering practice after training. We observed that our traditional 3-day-cycle surgical pathology cycle (day 1-grossing; day 2 -biopsies/frozens/preview; day 3 - sign-out) consistently and negatively impacted resident education by reducing preview time, case follow-up, immunohistochemical stain (IHC) interpretation, and molecular study integration. We aimed to create a modern surgical pathology rotation that improved performance and outcomes. We innovated our rotation to enhance resident education and ensure graduated responsibility. A novel 6-day cycle was created composed of 2 grossing days, 1 frozens/biopsies/preview days, 2 dedicated sign-out days, and 1 frozens/biopsies/case completion day. Residents completed surveys before implementing the new rotation and 6 months after implementation to track self-assessment of Accreditation Council for Graduate Medical Education (ACGME) milestone performance and internal quality control metrics. Clinical Competency Committee (CCC) annual evaluations were assessed in paired PGY levels pre- and post-intervention. After implementation, there was a statistically significant improvement in self-assessment of levels 4 and 5 of ACGME milestones and improved satisfaction of quality metrics, including time for previewing, reviewing IHC, graduated responsibility, and perceived readiness for independent practice. CCC evaluations showed overall maintained performance levels, with trends towards improvements in junior resident classes. Our 6-day cycle adequately fulfills the current demands of our sizeable academic center's surgical pathology training and can be a model for pathology residencies looking to modernize their surgical pathology rotations and resident education.

Updates in the pathology of Pregnancy Associated Breast Cancer (PABC).

Pregnancy associated breast cancer (PABC) is defined as a breast cancer diagnosed during gestation, lactation or within 5 years postpartum. While the development of malignancy during pregnancy is rare, the incidence is increasing. Breast cancer is one of the most common cancers diagnosed during pregnancy, affecting up to 1 in 3000 deliveries. New understanding of the pathophysiology of PABC recently resulted in updated definitions distinguishing breast cancer diagnosed during pregnancy (PrBC) from cancer diagnosed during the postpartum period (PPBC) due to distinct biology and prognosis. Pregnancy has a dual effect on breast cancer development- both protective against cancer and promoting tumor growth. While several hypotheses have been proposed over the years to explain these effects, the most likely hypothesis for the development of PABC is the involution hypothesis, proposing that remodeling programs activated in the immediate postpartum period are similar to wound healing and inflammation that may be associated with tumor development and progression. Although PABCs reflect all subtypes of breast carcinomas, they are most commonly invasive ductal carcinomas of high tumor grade and large tumor size, with more advanced stage at presentation and higher rates of lymph node involvement. Most PABCs are hormone negative tumors (triple negative or HER2 amplified tumors) with high Ki-67 proliferation rates. Several studies have shown that PABCs have different genomic signatures than non-PABC tumors, showing increased expression of immune response mediators. Better understanding of the molecular pathways of tumor initiation and progression, along with prompt diagnosis and novel treatment protocols in the care of PrBC and PPBC are needed to improve outcomes for these young, high-risk breast cancer patients.

The role of PRAME and NY-ESO-1 as potential therapeutic and prognostic biomarkers in triple-negative breast carcinomas.

PRAME and NY-ESO-1 are cancer-testis antigens (CTAs) reported to be highly enriched in triple-negative breast cancers (TNBCs), against which vaccines and immunotherapies are currently being developed. This study aims to analyze PRAME and NY-ESO-1 expression in TNBCs and their correlation with clinical outcomes. This is a retrospective cohort study of TNBC patients who have undergone neoadjuvant chemotherapy. PRAME and NY-ESO-1 expression were assessed on pre-therapy biopsies as H-scores (percentage x intensity) with final H scores of 2-3 considered as positive. Association between expression and pathologic complete response (pCR), metastasis, and residual cancer burden (RCB) were assessed via logistic regression. Cox proportional hazards models were used to assess the association with progression-free survival. P-values < 0.05 were considered statistically significant. Sixty-three percent of 76 patients were positive for PRAME. In contrast, only 5 % were positive for NY-ESO-1. PRAME positivity was significantly associated with a lower likelihood of early metastatic disease (OR = 0.24, 95 % CI 0.08-0.62; P = 0.005). However, it was not significantly associated with pCR, RCB category, or progression-free survival. NY-ESO1 score was not significantly associated with early metastatic disease, pCR, RCB category, or progression-free survival. Our results suggest that PRAME positivity may be associated with a lower risk of early metastasis in TNBCs, but not with response to neoadjuvant chemotherapy or progression-free survival. The high expression of PRAME in TNBCs makes it a potential therapeutic target, while NY-ESO1 appears to be a less useful marker. However, further larger studies are needed to ascertain the utility of these markers.

Neuroblastoma Arising in an Immature Teratoma of the Ovary in a 13-Year-Old.

Somatic malignancies arising in mature teratomas are exceedingly rare entities and even more so are those arising in immature teratomas. Here, we present a unique case of a 13-year-old who initially underwent ovarian sparing cystectomy for a 7.7 cm left ovarian mass with a pre-operative diagnosis of mature cystic teratoma. Histologically, all 3 germ cell layers were present and immature neuroepithelial tubules were also identified. Subsequent sections revealed a nodular lesion composed of neuropil, neuroblasts with a spectrum of maturation, and Schwannian-type stroma. The neuroblasts were diffusely positive for PHOX2B. Neuroblastoma arising in an immature teratoma has only been described in the literature once previously in an adult patient.

Correlation of manual semi-quantitative and automated quantitative Ki-67 proliferative index with OncotypeDXTM recurrence score in invasive breast carcinoma.

BACKGROUND: Ki-67 immunohistochemistry (IHC) staining is a widely used cancer proliferation assay; however, its limitations could be improved with automated scoring. The OncotypeDXTM Recurrence Score (ORS), which primarily evaluates cancer proliferation genes, is a prognostic indicator for breast cancer chemotherapy response; however, it is more expensive and slower than Ki-67. OBJECTIVE: To compare manual Ki-67 (mKi-67) with automated Ki-67 (aKi-67) algorithm results based on manually selected Ki-67 "hot spots" in breast cancer, and correlate both with ORS. METHODS: 105 invasive breast carcinoma cases from 100 patients at our institution (2011-2013) with available ORS were evaluated. Concordance was assessed via Cohen's Kappa (κ). RESULTS: 57/105 cases showed agreement between mKi-67 and aKi-67 (κ 0.31, 95% CI 0.18-0.45), with 41 cases overestimated by aKi-67. Concordance was higher when estimated on the same image (κ 0.53, 95% CI 0.37-0.69). Concordance between mKi-67 score and ORS was fair (κ 0.27, 95% CI 0.11-0.42), and concordance between aKi-67 and ORS was poor (κ 0.10, 95% CI -0.03-0.23). CONCLUSIONS: These results highlight the limits of Ki-67 algorithms that use manual "hot spot" selection. Due to suboptimal concordance, Ki-67 is likely most useful as a complement to, rather than a surrogate for ORS, regardless of scoring method.

Virtual Pathology Elective Provides Uninterrupted Medical Education and Impactful Pathology Education During the COVID-19 Pandemic.

As students do not qualify as essential health care workers, medical education faced severe disruptions during the COVID-19 pandemic including initial suspension of all in-person lectures and on-site rotations. Our Pathology Department was among the first at Northwestern to offer a completely virtual rotation with the goals of: (1) providing a comprehensive introduction to the practice of anatomic and clinical pathology, (2) emphasizing uninterrupted and continued excellence in education, and (3) minimizing exposure risk during the pandemic. The innovative 2-week curriculum incorporated diverse teaching modalities including live and recorded lectures; live and recorded video demonstrations; interactive small group discussions; interactive virtual sign-outs; and written and multimedia assignments, quizzes, and projects. The virtual elective ran from March to July 2020 with 52 total participating medical students. On post-rotation evaluations, students rated the pathology virtual elective 4.7/5.0 compared to other virtual rotations and 4.0/5.0 compared to all rotations (including in-person and virtual). Furthermore, continual improvements were made to the established framework based on rotation feedback such that curriculum content was more abundant and more favorably rated by the last cohort when compared to the first. Finally, although students identified interest in over 10 different medical specialties, all participants expressed increased interest in choosing pathology as a specialty and better understanding of pathology's role in patient care. We hope our detailed description of creating and evaluating a completely virtual elective rotation serves as a model for other departments to improve pathology education and visibility.

Clinicopathologic features of unexpectedly HER2 positive breast carcinomas: An institutional experience.

Human epidermal growth factor receptor 2 (HER2) overexpression occurs in 15-20 % of all breast carcinomas. These tumors are usually high-grade which often correlates with reduced overall survival and increased rates of recurrence. In a retrospective review, we identified 19 cases of unexpectedly HER2 positive (by immunohistochemistry and/or fluorescence in-situ hybridization) invasive breast carcinomas on core needle biopsies from a registry at Northwestern Memorial Hospital. These cases included low-grade tumors, invasive lobular carcinomas, classic type, and invasive carcinomas with special subtype features. Twelve of the tumors were histologic grade 1 and 7 were histologic grade 2. One of the grade 1 tumors had tubular features (8 %), 1 had cribriform features (8 %), 2 had mucinous features (17 %), 2 were invasive lobular carcinomas, classic type (17 %), and the rest were invasive carcinoma, no special type (50 %). The histologic grade 2 tumors included 5 invasive lobular carcinomas, classic type (71 %) and 2 invasive ductal carcinomas with mucinous features (29 %). By immunohistochemistry, 13 (65 %) were HER2 score 3+, 7 were score 2+ (35 %), and reflex fluorescence in-situ hybridization (FISH) testing showed amplification in 6 cases, with 1 equivocal case amplified on excision. Despite the HER2 positive status in the selected cases, no unique morphologic features that would indicate aggressive behavior were identified. In clinical follow up, two patients were found to have recurrences, five had lymph node metastasis, and one had distant metastasis. None of the patients with recurrent disease were treated with trastuzumab, despite their positive HER2 results. These findings support that our population of HER2 positive carcinomas showed a similar rate of lymph node metastases and recurrence as poorly-differentiated tumors, supporting HER2 positivity as a poor prognostic indicator, irrespective of morphologic features. We recommend continuing to test all breast cancers, regardless of grade or special subtype features, to provide the most comprehensive treatment and prognostic information for both clinicians and patients.

The PD-1/PD-L1 Axis in HER2+ Ductal Carcinoma In Situ (DCIS) of the Breast.

OBJECTIVES: The aims were to evaluate the programmed death 1 (PD-1)/programmed death ligand 1 (PD-L1) axis in ductal carcinoma in situ (DCIS) of the breast. METHODS: We reviewed 85 pure DCIS cases treated with surgical excision at our institution, including 51 luminal A (estrogen receptor [ER] positive/human epidermal growth factor 2 [HER2] negative), 15 luminal B (ER+/HER2+), 13 HER2 (ER-/HER2+), and six basal-like (ER-/HER2-/CK5/6+). The extent and intensity of PD-1 and PD-L1 immunohistochemical staining in the tumor-infiltrating lymphocytes (TILs) and in the tumor cells were recorded. RESULTS: Our study found that moderate/severe inflammation around DCIS correlated with HER2 expression (20/28 HER2+ cases [71%] vs 21/57 HER2- cases [37%], P = .005). Of interest, over half of the TILs around the HER2 subtype expressed PD-L1 (7/13, 54%). In addition, about one-third of TILs around the HER2 subtype expressed PD-1 (4/13, 31%). CONCLUSIONS: These findings suggest that immune-based therapeutic strategies may be used as a potential therapy in DCIS cases with PD-L1 overexpression, especially those of the HER2 molecular subtype.

Accreditation Council for Graduate Medical Education Self-Study for Pathology: One Institution's Experience and Lessons Learned.

CONTEXT.­: The Accreditation Council for Graduate Medical Education (ACGME) established a new system for accreditation of residency and fellowship programs in 2013. One key aspect of the Next Accreditation System is the 10-year self-study, which requires programs to conduct a comprehensive self-evaluation, including development of program aims and analysis of strengths, weaknesses, and environmental context, in order to plan improvements and take the program to the next level. OBJECTIVE.­: To provide a review of the recent changes and current state of ACGME accreditation, with a focus on the new 10-year self-study, and to share our institution's experience with conducting the first self-study of our pathology residency and accredited fellowship programs in 2018. DATA SOURCES.­: Review of English-language literature, published resources from the ACGME, and materials/data from our department's 2018 self-study. CONCLUSIONS.­: The self-study process now required for ACGME accreditation is a useful way to assess program strengths and weaknesses in the context of current environmental and institutional factors, and helps develop an effective framework for improvements geared at achieving program aims and taking the program to the next level. Additionally, conducting residency and fellowship self-studies together allows for collaboration, effective use of shared resources, and the development of a cohesive educational mission.

Ovarian Carcinosarcoma and Concurrent Serous Tubal Intraepithelial Carcinoma With Next-Generation Sequencing Suggesting an Origin From the Fallopian Tube.

Background. Ovarian carcinosarcomas are rare aggressive biphasic tumors. Evidence suggests that these tumors are monoclonal and that the sarcoma component is derived from a stem cell undergoing divergent differentiation. Currently, there remains a paucity of data regarding its origin, with few reports suggesting an association with serous tubal intraepithelial carcinoma (STIC) by immunohistochemistry and genetics. Objective. We sought to determine the relationship of carcinosarcoma to high-grade serous carcinoma and STIC by investigating for similar mutation signatures through next-generation sequencing. Methodology. A case of carcinosarcoma with associated high-grade serous carcinoma and STIC was macrodissected, and next-generation sequencing was performed on each component separately. Results. The STIC, high-grade serous carcinoma component, and chondrosarcoma component were all diffusely positive for p53 and p16 by immunohistochemistry. Next-generation sequencing demonstrated an identical TP53 gene c.376-1G>A 5' splice site pathogenic mutation in all 3 components. Conclusions. Our findings suggest that carcinosarcomas may also originate from the fallopian tube.

Expression of HPV-induced DNA Damage Repair Factors Correlates With CIN Progression.

Human papillomaviruses (HPVs) are DNA viruses with epithelial tropism. High-risk types of HPV are the causative agents of the majority of cervical cancers and are responsible for a number of other anogenital as well as oropharyngeal cancers. The life cycle of HPV is closely linked to the differentiation state of its host cell and is dependent on the activation of specific pathways of the DNA damage response. Several proteins from the ataxia telangiectasia mutated and the ataxia telangiectasia mutated and Rad3-related DNA repair pathways, which are essential for maintaining genomic stability in cells, are upregulated in HPV-positive cells and are required for viral replication. Our studies examine the expression of 5 such DNA repair factors-pCHK2, pCHK1, FANCD2, BRCA1, and H2AX-in cervical specimens from patients diagnosed with low-grade, intermediate-grade, or high-grade lesions. The percentage of cells expressing pCHK2, pCHK1, FANCD2, and BRCA1 is significantly higher in high-grade squamous intraepithelial lesions compared with that of either low-grade squamous intraepithelial lesions or normal tissue, particularly in differentiated cell layers. In addition, the distribution of this staining throughout the epithelium is altered with increasing lesion grade. This study characterizes the expression of pCHK2, pCHK1, FANCD2, H2AX and BRCA1 during cervical cancer progression and provides additional insight into the role of these DNA damage response proteins in viral transformation.

A pilot study of durvalumab and tremelimumab and immunogenomic dynamics in metastatic breast cancer.

Immune checkpoint inhibitors produce modest responses in metastatic breast cancer, however, combination approaches may improve responses. A single arm pilot study was designed to determine the overall response rate (ORR) of durvalumab and tremelimumab, and evaluate immunogenomic dynamics in metastatic endocrine receptor (ER) positive or triple negative breast cancer (TNBC). Simon two-stage design indicated at least four responses from the first 18 patients were needed to proceed with the second stage. T-cell receptor (TCR) sequencing and immune-gene expression profiling were conducted at baseline and two months, whole exome sequencing was conducted at baseline. Eighteen evaluable patients were accrued (11 ER-positive; seven TNBC). Only three patients had a response (ORR = 17%), thus the study did not proceed to the second stage. Responses were only observed in patients with TNBC (ORR = 43%). Responders versus non-responders had upregulation of CD8, granzyme A, and perforin 1 gene expression, and higher mutational and neoantigen burden. Patients with TNBC had an oligoclonal shift of the most abundant TCR-beta clonotypes compared to those with ER-positive disease, p = 0.004. We conclude responses are low in unselected metastatic breast cancer, however, higher rates of clinical benefit were observed in TNBC. Immunogenomic dynamics may help identify phenotypes most likely to respond to immunotherapy.

Double-Equivocal HER2 Invasive Breast Carcinomas: Institutional Experience and Review of Literature.

CONTEXT.­: HER2 status is a prognostic factor and therapeutic target in invasive breast carcinomas. Reflex testing using an alternate method is recommended on equivocal cases via immunohistochemistry or fluorescence in situ hybridization (FISH). Therapeutic dilemmas arise when both tests are equivocal. The standard chromosome 17 centromere reference probe (CEP17) is in close proximity to the HER2 locus and may be coamplified, leading to equivocal results. Alternate chromosome 17 reference probes may aid in establishing the true HER2 status. OBJECTIVE.­: To describe our institutional experience using D17S122 probe for reflex FISH testing on double-equivocal invasive breast carcinomas and review the literature on alternate reference probes. DATA SOURCES.­: Twenty-two patients with double-equivocal invasive breast carcinomas, defined as HER2 immunohistochemistry score 2+ and FISH equivocal per the 2013 guidelines, were reviewed. Reflex FISH was performed with alternate probe D17S122 and the HER2 status classified for 11 cases by using a revised HER2: D17S122 ratio. Seven of 11 cases (63.6%) were ultimately classified as HER2 positive, while 4 cases (36.4%) remained equivocal. The 7 positive cases showed a HER2: D17S122 greater than 2.0. CONCLUSIONS.­: Alternate probe D17S122 reclassified more than half of our cases as HER2 positive. Alternate probes may establish true HER2 status and direct proper management, as evidenced by our experience and the literature. Additional investigation is needed to determine which alternate probe(s) is(are) best for reflex testing. Finally, the American Society of Clinical Oncology/College of American Pathologists guidelines may need to be updated to reflect more specific recommendations for the utilization of appropriate probes in double-equivocal HER2 cases.

p16 Expression and Biological Behavior of Flat Vulvar Low-grade Squamous Intraepithelial Lesions (LSIL).

Flat low-grade squamous intraepithelial lesion (LSIL) of the vulva [vulvar intraepithelial neoplasia (VIN) 1, flat condyloma] is an uncommon entity with poorly understood biological behavior. We aimed to determine the risk of subsequent vulvar high-grade squamous intraepithelial lesion (HSIL) or carcinoma following a diagnosis of vulvar LSIL/VIN 1, as well as the frequency and predictive value of p16 immunohistochemical expression in this setting. Of the 51 included cases, p16 positivity (diffuse block staining) was identified in 2 (4%). Follow-up data were available in 34 cases, of which 2 (5.9%) developed subsequent vulvar HSIL, including 1/2 p16-positive cases and 1/32 p16-negative cases. The difference in HSIL frequency between p16-positive and p16-negative cases was not statistically significant (P=0.116 for VIN 2+, P=0.061 for VIN 3). For the 18 patients with treatment information available, 10 (56%) received medical or surgical treatment after biopsy. Our results indicate that flat vulvar LSIL is infrequently p16 positive, and that few patients with vulvar LSIL develop subsequent vulvar HSIL. Despite the use of destructive treatment in some cases, the data provide support for the nonpreneoplastic nature of the entity. Immunohistochemical expression of p16 may not be a predictor of HSIL risk in vulvar LSIL, although this result may also be related to the very low rates of both p16 positivity and subsequent vulvar HSIL in our sample. It is clear that vulvar LSIL is distinct from LSIL in other lower anogenital sites in terms of its behavior and p16 expression frequency.

Steroid hormone synthesis by the ovarian stroma surrounding epithelial ovarian tumors: a potential mechanism in ovarian tumorigenesis.

Epithelial ovarian tumors are responsive to steroid hormone stimulation and the ovarian stroma may have a direct role in this process. We evaluated immunohistochemical markers of sex-steroid differentiation and steroidogenesis (calretinin, inhibin, steroidogenic factor 1), steroid enzymes involved in hormone biosynthesis (CYP17, CYP19, HSD17ß1, AKR1C3), and hormone receptors (estrogen receptor, progesterone receptor, and androgen receptor) in 101 epithelial ovarian tumors and in normal structures implicated in ovarian carcinogenesis (ovarian surface epithelium and cortical inclusion cysts) in an attempt to elucidate this process. We hypothesized that ovarian stroma immediately adjacent to tumors express markers of sex-steroid differentiation and steroidogenesis and steroid enzymes whereas the epithelium contains corresponding hormone receptors. As the findings in seromucinous, endometrioid, and clear cell neoplasms, tumors closely associated with endometriosis, were very similar, these were combined into a group designated 'endometriosis-related tumors.' Significantly increased expression of markers of sex-steroid differentiation and steroidogenesis was found in stroma immediately adjacent to endometriosis-related tumors (P=0.003) and mucinous tumors (primary and metastatic mucinous tumors were combined because of similar findings) (P<0.0001) compared with more remote ovarian stroma. In addition, sex-steroid enzymes were increased in stroma adjacent to endometriosis-related tumors (P=0.02) and mucinous tumors (P=0.02) compared with more distant stroma. Steroid hormone receptors showed greater expression in epithelium compared with stroma in the endometriosis-related tumors (P=0.0009), low-grade serous tumors (P<0.0001), and high-grade serous carcinoma (P=0.0036). In contrast, there was greater expression in stroma compared with epithelium (P<0.0001) in mucinous tumors, which may be due to the fact that they are not derived from müllerian epithelium. In conclusion, our findings strongly support the view that the stroma surrounding epithelial tumors in the ovary is activated to elaborate steroid hormones which may stimulate further neoplastic growth. The precise mechanisms by which this process might occur are complex and require further investigation.

Multinucleation is an objective feature useful in the diagnosis of pleomorphic lobular carcinoma in situ.

OBJECTIVES: Bi- and multinucleated (B/M) cells are present in a variety of tumors. We evaluated lobular carcinoma in situ (classic and pleomorphic types) and ductal carcinoma in situ (DCIS) to determine if this objective morphologic feature aids the differential diagnosis. METHODS: The number of B/M cells was recorded in pleomorphic lobular carcinoma in situ (PLCIS) (n = 20), classic lobular carcinoma in situ (CLCIS) (n = 26), and DCIS (n = 37). RESULTS: Binucleated cells were significantly more frequent in PLCIS (100%) vs DCIS (43%; P < .0001) and CLCIS (54%; P = .0004). Multinucleated cells were present in 25% of PLCIS cases and 8% of DCIS cases, and they were absent in CLCIS. The quantity of B/M per high-power field (hpf) was less in DCIS (mean, 1.1) and CLCIS (mean, 2.5) compared with PLCIS (mean, 5.8). Thirty-five percent of PLCIS cases had more than five B/M per hpf. CONCLUSIONS: Binucleated cells are significantly more frequent in PLCIS vs CLCIS and DCIS. Multinucleated cells were never identified in CLCIS. PLCIS should be considered as a diagnosis when B/M is noted.