Extrauterine High-grade Serous Carcinoma Research Articles

Genomic Catastrophe (Chromothripsis and Polyploidy) Correlates With Tumor Distribution in Extrauterine High-grade Serous Carcinoma.

Most extrauterine high-grade serous carcinomas (HGSCs) are thought to develop first in the distal fallopian tube. Most models of HGSC assume origin from relatively stable, noninvasive serous tubal intraepithelial carcinomas. However, widespread tumor involvement in the absence of a serous tubal intraepithelial carcinoma could occur after catastrophic genomic events (CGEs; such as chromothripsis or polyploidy). Twenty-six HGSCs assigned to fallopian tube (n = 9, group 1) and/or ovary (n = 9, group 2), and primary peritoneal (n = 8, group 3) were assessed by microarray (Oncoscan). CGEs were identified in 15/26 (57.7%); chromothripsis-like pattern in 13/26 (50.0%) and polyploidy in 6/26 (23.1%). CGE was seen in 4/9 (44.4%), 9/9 (100%), and 2/8 (25%) cases in groups 1. 2, and 3, respectively. Overall, CGEs were seen in 9/9 (100%) cases with grossly evident ovarian parenchymal involvement versus 6/17 (35.3%) without (P = 0.0024). Ovarian size (measured on the long axis) correlated with CGE positivity (P = 0.016). CGEs are significantly more common in HGSCs with ovarian parenchymal involvement compared with those limited to the fallopian tube and/or extraovarian tissues. These associations suggest geographically different tumor growth patterns and support the subdivision of HGSCs according to not only the stage but also tumor distribution. They have implications for clinical and pathologic presentation, trajectory of tumor evolution, and in the case of primary peritoneal HGSCs, potentially unique precursors to tumor transitions that could inform or influence cancer prevention efforts.

CytoSaLPs score: a promising new tool for the detection and screening of extrauterine high grade serous carcinoma

BackgroundA recent theory supports that high-grade serous epithelial ovarian cancer derives from the fimbrial end of the fallopian tube and during the last decade, a few studies have examined the fallopian tube cytology. Our study aims to determine the cytomorphological characteristics of both benign and non-benign salpingeal samples, in order to establish fallopian cytology as a valuable diagnostic test for women with high risk for development of ovarian/fallopian/peritoneal cancer.MethodsOur study included patients undergoing salpingoophorectomy or total hysterectomy and salpingoophorectomy for any gynecological pathology. Using a soft brush, fallopian tube smears from the fimbrial end were collected ex vivo. The Cytologists of our Institution described the morphological characteristics of the fallopian cells by adopting a proposed Table, which had a calibration system ranging from 3 to 29. This Table is referred to as the CytoSaLPs Score. Our study compared the two diagnostic cytological methods, the one of the conventional cytology and the other using the CytoSaLPs Score, having as gold standard the tubal’s pathological findings.ResultsA total of 230 tubal specimens from 144 patients were included in this study. The Score’s mean for the benign and non-benign arm was 12.8 and 18.7 respectively. The cut-off point for both arms was 16.5. The CytoSaLPs Score tool showed significantly higher specificity (87.50% vs. 75.96, p-value < 0.001) and positive predictive value PPV (40.91% vs. 26.47%, p-value < 0.001) compared to conventional cytology. Regarding the accuracy, the Score’s superiority is highlighted (86.96% vs. 76.52%, p-value < 0.001).ConclutionsThe evaluation of tubal cytology using the CytoSaLPs Score could be used as a reliable diagnostic method. Further evaluation with larger studies is warranted.

Progress in the pathological arena of gynecological cancers.

This review covers the significant new developments in the pathological classification of gynecological tumors. Many of these were included in the updated World Health Organization Classification of Female Genital Tract Tumours, published in 2020. Topics include the compelling evidence that a large majority of extrauterine high‐grade serous carcinomas arise from the fallopian tube; the Cancer Genome Atlas (TCGA) Classification of endometrial carcinomas; the discovery that most so‐called synchronous endometrial and ovarian endometrioid carcinomas represent metastasis from the endometrium to the ovary; and the division of cervical, vaginal, and vulval carcinomas into clinically meaningful HPV‐associated and HPV‐independent types. Newly described tumor types are covered, including endometrial and ovarian mesonephric‐like adenocarcinoma, uterine sarcoma types associated with specific molecular abnormalities, and gastric (gastrointestinal)‐type adenocarcinomas of the endometrium and vagina. Important molecular events in ovarian sex cord–stromal tumors are also discussed.

A Modified 2 Tier Chemotherapy Response Score (CRS) and Other Histopathologic Features for Predicting Outcomes of Patients with Advanced Extrauterine High-Grade Serous Carcinoma after Neoadjuvant Chemotherapy.

Simple SummaryReliable predictive indicators of response to neoadjuvant chemotherapy of advanced-stage extrauterine high-grade serous carcinoma are still lacking. Moreover, changes evident in tumor samples from interval surgery are not well understood. Our retrospective study aimed to address the prognostic value of chemotherapy response score (CRS) and identify additional predictive features for the risk of progression and death. In a cohort of 245 patients, we demonstrate that the modified two-tier CRS was prognostic for survival, and this significance was independent of scoring site; our data support expansion of CRS use to the adnexal samples. In addition to the CRS, oncocytic change, inflammation, and desmoplasia were additional histopathologic parameters related to survival. We recommend using the two-tier CRS, together with the additional histological features serving as secondary criteria for scoring, to identify patients at high risk for recurrence, allow tailored adjuvant therapy strategies, or consider clinical trials.Background: The impact of chemotherapy response score (CRS) on prognosis has varied among studies. We addressed the prognostic significance of CRS and the prognostic value of previously undescribed histologic features using a cohort of 245 patients. Methods: Retrospective study in patients with advanced extrauterine high-grade serous carcinomas treated with neoadjuvant chemotherapy followed by interval tumor reductive surgery from 1990 to 2018 in our hospital. Gynecologic pathologists assessed tumor CRS and other histologic features. Clinical information was collected, and multivariate analyses were conducted. Results: A modified 2 tier CRS (CRS 1/2 versus CRS 3) was significantly associated, independent of scoring site (omental versus adnexal), with overall survival (OS) (omentum, p = 0.018; adnexa, p = 0.042; entire cohort, p = 0.002) and progression-free survival (PFS) (p = 0.021, p = 0.035, and p = 0.001, respectively). On multivariate survival analysis, 2 tier CRS, oncocytic change, inflammation, and desmoplasia were significant for OS (p = 0.034, p = 0.020, p = 0.007, and p = 0.010, respectively). Likewise, 2 tier CRS, inflammation, and desmoplasia were significant for PFS (p = 0.012, p = 0.003, p = 0.011, respectively). Conclusions: The modified 2 tier CRS was significantly associated with survival, independent of scoring site. Additional histologic features including oncocytic change, inflammation, and desmoplasia can also predict patient outcomes.

Increase of fallopian tube and decrease of ovarian carcinoma: fact or fake?

Accurate disease classification is fundamental for the selection of the treatment approach, prognostication, selection of clinical trials and for research purposes in routine clinical practice. Extrauterine high-grade serous carcinoma (HG-SC) may arise from the ovary, the fallopian tube and rarely from the peritoneal surface epithelium. Regardless of its origin, the vast majority of patients with HG-SC share clinical symptoms, present with advanced stage disease and suffer from a poor prognosis. Recent data suggest that there is an increasing incidence of HG-SC arising from the fallopian tube. Data from the Clinical Cancer Registry of Leipzig of surgically treated non-uterine pelvic carcinomas were analyzed regarding their sites of origin. Depending on the histology, cases were separated into high-grade serous and non-high-grade serous tumors. Based on different approaches in the assessment of the site of origin, three distinct time periods were defined. The frequency of the specific sites of origin was compared to the different time periods and histologic subtypes. The majority of cases (57.9%; 279/482) were high-grade serous carcinomas, 42.1% of the cases presented with endometrioid, clear cell or mucinous histology. Overall, a 1.7-fold decrease of carcinomas with ovarian origin, paralleled by a 10.3-fold increase of tubal carcinomas was noted between 2000 and 2019. Based on the histopathological subtype, there was a 2.1-fold decrease of ovarian and a 7.1-fold increase of tubal carcinomas in patients with HG-SC. In non-high-grade serous tumors, the frequency of the different sites of origin did not change. 83.7% of tumors with non-high-grade serous histology originated from the ovary, whereas 86.8% of the carcinomas with tubal origin were of high-grade serous histology. The present and published data of non-uterine pelvic cancers may suggest an increase of tubal and decrease of ovarian carcinomas. However, there is rising morphologic and molecular evidence that non-uterine HG-SC actually arise from the fallopian tubes via its precursor STIC instead of from the ovary. This evidence has had an impact on the handling and reporting of non-uterine surgical specimens and its definition of the site assessment. In conclusion, the increasing frequency of tubal carcinomas and the associated decrease in ovarian cancer appears to be due to the reclassification of tumors previously classified as ovarian and greater emphasis on examining the resection specimens of non-uterine pelvic carcinomas.

Magnetic resonance imaging findings of extrauterine high-grade serous carcinoma based on new pathologic criteria for primary site assignment.

There has been no study that has reported magnetic resonance imaging (MRI) findings of extrauterine high-grade serous carcinomas (HGSCs) that have been histologically determined by the new criteria. To assess MRI findings of extrauterine HGSCs based on new pathologic criteria. Fifty patients with histopathologically proven extrauterine HGSCs, who underwent pretreatment gadolinium-enhanced MRI, were included in this study. After surgery, the primary sites were histopathologically determined based on new criteria for primary site assignment in extrauterine HGSCs as follows: fallopian tube (n = 34); ovary (n = 9); primary peritoneal HGSC (n = 1); and tubo-ovarian (n = 6). We retrospectively reviewed MR images and compared the MR findings between tubal and ovarian primaries. MRI patterns with tubal primaries were classified as ovarian cancer (62%), peritoneal cancer (35%), and fallopian tube cancer (3%). MRI patterns with ovarian primaries were classified as ovarian cancer (78%) and peritoneal cancer (22%). The frequency of the involvement of the fallopian tube, ovary, peritoneum, uterus, and lymph node was not significantly different between the two pathologies. There was no significant difference in the abnormal amount of ascites, hemorrhagic ascites, or characteristics of the ovarian lesions between the two pathologies. On MR images, tubal primaries almost always exhibited ovarian or peritoneal cancer pattern, but rarely exhibited fallopian tube cancer pattern. MR findings could not accurately differentiate between tubal and ovarian primaries; therefore, histopathologic investigation is essential for determination of the primary site of extrauterine HGSCs.

Lymphatic Invasion in the Fallopian Tube is a Late Event in the Progression of Pelvic Serous Carcinoma and Correlates With Distant Metastasis.

The majority of extrauterine high-grade serous carcinomas are believed to arise in the fallopian tube as serous tubal intraepithelial carcinomas. The primary mode of metastasis is intraperitoneal, and patients usually present with peritoneal carcinomatosis. Although the tubes have a rich lymphatic network, tubal lymphatic invasion is observed in only a minority of cases. Fallopian tube sections from 222 patients with advanced stage high-grade extrauterine serous carcinoma were reviewed and lymphatic invasion within the lamina propria and myosalpinx were assessed. Seventeen patients were FIGO stage II, 162 stage III, and 43 stage IV. Tubal lymphatic invasion was identified in 44 cases (19.7%). Among the cases with lymphatic invasion, nonfimbrial lamina propria, fimbrial lamina propria, and myosalpingeal lymphatic invasion were present in 23 (52%), 21 (48%), and 21 (48%), respectively. Among cases with lymphatic invasion, 16 (36%) were FIGO stage IV, while among cases without lymphatic invasion, 27 (15%) were stage IV (P=0.0014, χ). In summary, in women with advanced stage high-grade extrauterine serous carcinoma, lymphatic invasion in the fallopian tube is uncommon, and is more than twice as likely to be associated with distant metastases as compared with those without tubal lymphatic invasion.

A 3-Tier Chemotherapy Response Score for Ovarian/Fallopian Tube/Peritoneal High-grade Serous Carcinoma: Is it Clinically Relevant?

The chemotherapy response score (CRS) is used to score histopathologic response to neoadjuvant chemotherapy (NACT) of patients with extrauterine high-grade serous carcinoma. This study was undertaken to determine if the CRS in the omentum, adnexa or when combined correlates with (1) progression-free survival (PFS) or overall survival (OS), (2) laparoscopic score of abdominal disease, (3) Cancer antigen 125 levels, (4) BRCA status, and (5) platinum-resistant disease. A total of 158 cases were retrospectively collected that received NACT between April 2013 and February 2018 at a single institution. The 3-tier Böhm CRS system was applied to the omentum and adnexa. Survival outcomes between scored subgroups were analyzed using Cox proportional hazards regression. Spearman rank correlation analyses were used to assess CRS and clinical data. A total of 119 cases were treated only with carboplatin/paclitaxel. Omental CRS was: 1 (23 cases, 19.3%), 2 (65 cases, 54.6%), and 3 (31 cases, 26.1%), whereas adnexal CRS was: 1 (50 cases, 42%), 2 (48 cases, 40.3%) and 3 (21 cases, 17.6%). The omental CRS was significantly associated with PFS as a 2-tier score (hazard ratio [HR]=0.612, 95% confidence interval [CI]: 0.378-0.989, P=0.045) but not associated with the PFS using the 3-tier score or with OS using either system. Adnexal CRS was not associated with OS but was significantly associated with PFS using the 3-tier (HR=0.49, 95% CI: 0.263-0.914, P=0.025) and 2-tier scores (HR=0.535, 95% CI: 0.297-0.963, P=0.037). The combined score was not associated with OS but was significantly associated with PFS using the 3-tier (HR=0.348, 95% CI: 0.137-0.88, P=0.026) and 2-tier scores (HR=0.364, 95% CI: 0.148-0.896, P=0.028). No CRS system used associated with laparoscopic assessment of disease. CRS in the omentum had no significant association with platinum resistance; however, the adnexal CRS 1/2 were 3 times as likely to develop platinum resistance compared with CRS 3 (relative risk=3.94, 95% CI: 1.03-15.09, P=0.046). The CRS, when used on the omentum, adnexa, and as a combined score, was significantly associated with PFS but not with OS. Adnexal CRS 1/2 are more likely to develop platinum-resistant disease. Therefore, the use of this pathology parameter may be useful for clinical management.

Bilateral serous tubal intraepithelial carcinoma associated with high-grade serous carcinoma of the peritoneum

Serous tubal intraepithelial carcinoma (STIC) is now considered a putative precursor lesion of most extrauterine high-grade serous carcinomas (HGSC). It is frequently reported in high-risk women and women with advanced-stage serous carcinoma. This case study reports a serous high-grade carcinoma (HGSC) consisting of a bilateral STIC with a focus of stromal invasion in the left tube, and a peritoneal HGSC. The grossly normal-appearing tubes including the fimbriated ends were sectioned following the SEE-FIM protocol. In both tubes, tumor aggregates were exfoliated extensively to the tubal lumens. The neoplastic epithelia in any location were diffusely positive for p53 in strong nuclear patterns. Pelvic lymph nodes were negative for tumor on serial sections and keratin 7 immunohistochemistry, and there was no evidence of lymphatic vessel involvement. The lack of any evidence of lymphovascular invasion and regional lymph node metastases supports the interpretation of intraluminal and transcoelomic spread, and may be taken as evidence of dissemination of tubal neoplastic cells by exfoliation in this case. The biology of transcoelomic spread is reviewed in this manuscript.

Disease Distribution in Low-stage Tubo-ovarian High-grade Serous Carcinoma (HGSC): Implications for Assigning Primary Site and FIGO Stage.

The latest FIGO and TNM (eighth edition) staging systems for ovarian, tubal, and peritoneal neoplasms require primary site assignment as tubal/ovarian/peritoneal, but provide no guidance or criteria. Fewer than 10% of extrauterine high-grade serous carcinoma (HGSC) cases present at low stage (stage I/II). Low-stage cases offer a unique opportunity to understand the pattern of disease early in its evolution prior to wide dissemination and provide valuable evidence for guiding specimen handling and tumor staging. This study aimed to examine disease distribution in low-stage tubo-ovarian HGSC. Anonymized pathology reports of 152 stage I/II extrauterine HGSCs from 6 teaching hospitals were analyzed: group 1 (n=67) comprised cases with complete tubal examination by Sectioning and Extensively Examining the FIMbriated end of the tube (SEE-FIM) and group 2 (n=85) consisted of cases without documentation of both tubes being fully examined by the SEE-FIM or a SEE-FIM-like protocol. The stage, site/pattern of involvement, site/size of largest tumor focus and laterality of tubal and ovarian involvement were recorded. Tubal mucosal involvement was present in 95% of optimally examined cases and many factors influenced detection of tubal disease. Bilateral involvement, suggestive of metastasis, was significantly more frequent in the ovaries (35%) than the tubes (9%) (P<0.0001, Fisher exact test). No case showed a complete absence of tubal/ovarian involvement, questioning the biological existence of primary peritoneal HGSC. Disease distribution in low-stage cases supports a tubal origin for most HGSCs. Detailed tubal sampling upstages some apparent stage I cases through detection of microscopic tubal involvement.

Extrauterine high-grade serous carcinomas with bilateral adnexal involvement as the only two disease sites are clonal based on tp53 sequencing results: implications for biology, classification, and staging.

A previous multicenter study of 67 cases of Stage I/II tubo-ovarian high-grade serous carcinoma with complete tubal sampling identified 7 cases in which there were only two disease sites, comprising tumor involving opposite adnexa with no extra-adnexal involvement. This study aimed to determine whether such low-stage extrauterine high-grade serous carcinomas with only two sites of involvement, located on opposite adnexa, have identical or different TP53 mutations in order to investigate their clonal relationship. DNA extracted from both sites of involvement was subjected to TP53 sequencing (n=6) or sequencing of one site and mutation confirmation by droplet digital PCR for the other site (n=1). Of the 7 cases analyzed, 1 case had unilateral serous tubal intraepithelial carcinoma with contralateral ovarian high-grade serous carcinoma, 3 had tubal high-grade serous carcinomas (±serous tubal intraepithelial carcinoma) with contralateral ovarian high-grade serous carcinoma, 2 had bilateral ovarian high-grade serous carcinomas with normal tubes, and 1 had bilateral fallopian tube high-grade serous carcinoma with normal ovaries. All 7 cases showed identical TP53 mutations in tumor from both disease sites. Therefore, these rare cases of high-grade serous carcinoma confined to opposite adnexa all show clonal identity between the two sites of involvement, suggesting unifocal origin and metastasis rather than multifocal origin. Our results suggest that serous tubal intraepithelial carcinoma or adnexal high-grade serous carcinoma can metastasize to the contralateral adnexa without peritoneal involvement. Given the clonal relationship between the two sites, such cases should be considered stage II, with stage I reserved for cases with unilateral and unifocal adnexal involvement. Furthermore, serous tubal intraepithelial carcinoma without invasion should be taken to constitute a disease site for staging purposes.

High-grade serous carcinoma of tubo-ovarian origin: recent developments.

Extra-uterine high-grade serous carcinoma (HGSC) accounts for most of the morbidity and mortality associated with ovarian carcinoma, and is one of the leading causes of cancer death in women. Until recently our understanding of HGSC was very limited compared to other common cancers, and it has only been during the last 15 years that we have learned how to diagnose this ovarian carcinoma histotype accurately. Since then, however, there has been rapid progress, with identification of a precursor lesion in the fallopian tube, development of prevention strategies for both those with inherited susceptibility (hereditary breast and ovarian cancer syndrome) and without the syndrome, and elucidation of the molecular events important in oncogenesis. This molecular understanding has led to new treatment strategies for HGSC, with the promise of more to come in the near future. In this review we focus on these recent changes, including diagnostic criteria/differential diagnosis, primary site assignment, precursor lesions and the molecular pathology of HGSC.

The Fallopian Tube Origin and Primary Site Assignment in Extrauterine High-grade Serous Carcinoma: Findings of a Survey of Pathologists and Clinicians

Accumulating recent evidence suggests that the majority of extrauterine high-grade serous carcinomas (HGSCs) do not arise from the ovary as historically accepted but from the distal, fimbrial end of the fallopian tube from a precursor known as serous tubal intraepithelial carcinoma. There has been variable acceptance of this evidence among pathologists and clinicians dealing with "ovarian" cancer and this has resulted in wide variation in the assignment of primary site between different institutions when HGSC involves >1 anatomic site. This has obvious implications for cancer epidemiology, registration, and entry into clinical trials. We undertook a survey of members of several national and international gynecologic pathology and clinical cancer societies with a view to ascertaining the degree of acceptance of the fallopian tube origin of extrauterine HGSC and to explore various aspects regarding site assignment, pathologic sampling, diagnosis, FIGO staging, and reporting of these neoplasms. The results indicate wide acceptance among both pathologists and clinicians of the fallopian tube theory of origin of HGSC (86% pathologists, 92% clinicians), although there is significant variation regarding the perceived importance of assigning a primary site given the limited prognostic and therapeutic significance. Interestingly, clinicians feel it is more important to assign a primary site than pathologists (71% vs. 49%). The survey also indicates widespread acceptance of recently proposed criteria for site assignment in extrauterine HGSC.

Incidental Serous Tubal Intraepithelial Carcinoma and Non-Neoplastic Conditions of the Fallopian Tubes in Grossly Normal Adnexa: A Clinicopathologic Study of 388 Completely Embedded Cases.

Serous tubal intraepithelial carcinoma (STIC), the putative precursor of the majority of extrauterine high-grade serous carcinomas, has been reported in both high-risk women (those with a germline BRCA mutation, a personal history of breast carcinoma, and/or family history of breast or ovarian carcinoma) and average risk women from the general population. We reviewed grossly normal adnexal specimens from 388 consecutive, unselected women undergoing surgery, including those with germline BRCA mutation (37 patients), personal history of breast cancer or family history of breast/ovarian cancer (74 patients), endometrial cancer (175 patients), and a variety of other conditions (102 patients). Among 111 high-risk cases and 277 non-high-risk cases, 3 STICs were identified (0.8%), all in non-high-risk women (high risk vs. non-high risk: P=not significant). STIC was found in 2 women with nonserous endometrial carcinoma and 1 with complex atypical endometrial hyperplasia. Salpingoliths (mucosal calcifications), found in 9% of high-risk cases, and fimbrial adenofibromas in 9.9% of high-risk cases, were significantly more common in high-risk as compared with non-high-risk women (1.8% and 2.5%, respectively; P<0.007). Mucinous metaplasia was found in 3.1%, salpingitis isthmica nodosa in 3.4%, hemosiderin or pseudoxanthoma cells in 4.9%, and fibrous luminal nodules in 4.1%. None of these latter features differed significantly in the high-risk versus non-high-risk groups. These findings suggest a possible association between STIC and endometrial hyperplasia and carcinoma, and clarify the frequency of non-neoplastic tubal findings in grossly normal fallopian tubes.

Invasion Patterns of Metastatic Extrauterine High-grade Serous Carcinoma With BRCA Germline Mutation and Correlation With Clinical Outcomes.

Characteristic histopathologic features have been described in high-grade serous carcinoma associated with BRCA abnormalities (HGSC-BRCA), which are known to have relatively favorable clinical outcomes. The aim of this study was to evaluate the clinical significance of invasion patterns in metastatic HGSC-BRCA cases. Of the 37 cases of advanced-stage HGSC with known BRCA1 or BRCA2 germline mutation retrieved from our institutional files, 23 patients had a germline mutation of BRCA1 and 14 had a BRCA2 mutation. The pattern of invasion at metastatic sites was recorded and classified as a pushing pattern (either predominantly or exclusively), an exclusively micropapillary infiltrative pattern, or an infiltrative pattern composed of papillae, micropapillae, glands, and nests (mixed infiltrative pattern). Histologic evaluation of metastases was performed without knowledge of genotype or clinical outcome. Clinical data were abstracted from medical records. Median age was 56 years (range, 31 to 73 y). All patients presented at stage IIIC or IV and underwent complete surgical staging followed by chemotherapy. All 37 HGSC-BRCA cases showed either pushing pattern metastases (30; 81%) or infiltrative micropapillary metastases (7; 19%). No HGSC-BRCA case exhibited metastases composed solely of mixed infiltrative patterns. Among the 7 infiltrative micropapillary cases, 6 had a BRCA1 germline mutation versus 1 with a BRCA2 mutation. The median time of follow-up was 26 months (range, 13 to 49 mo). All 7 patients with infiltrative micropapillary metastases either experienced recurrence or died of disease (5 recurrences and 2 deaths), which was significantly worse than what was seen in patients with predominantly pushing pattern metastases, of whom 16 of 30 (53%) experienced recurrence (n=14) or died of disease (n=2) (P=0.03). In conclusion, the recognition of different invasion patterns of metastatic extrauterine HGSC-BRCA has prognostic implications. The infiltrative micropapillary pattern is associated with poor outcomes and is more frequently seen in BRCA1-associated HGSC than in BRCA2 cases.

Serous tubal intraepithelial carcinoma localizes to the tubal-peritoneal junction: a pivotal clue to the site of origin of extrauterine high-grade serous carcinoma (ovarian cancer).

Recent data suggest that intraepithelial carcinoma of the fallopian tube [serous tubal intraepithelial carcinoma (STIC)] is the precursor of high-grade extrauterine serous carcinoma. A more specific location for the origin of this lesion is suggested by the recently described junction between the fallopian tubal epithelium and the peritoneum [tubal-peritoneal junction (TPJ)]. Fallopian tubes from 202 patients with advanced-stage high-grade extrauterine serous carcinoma or carcinosarcoma were evaluated histologically as were 124 prophylactic salpingo-oophorectomy specimens. These included 54 patients with BRCA or other high-risk mutation or a family history of BRCA mutation and 70 with a personal or family history of breast carcinoma. STIC was found in 81 of 202 patients with serous carcinoma (40.1%). STIC was present in 73 of 141 (52%) cases in which the fimbriae were present and in 62 of 100 (62%) cases in which the TPJ was present (P not significant). In comparison with these groups, when fimbriae and TPJ were absent, STIC was found in 8 of 61 (13%) cases (P<0.0001). None of the prophylactic specimens contained STIC. The mean size of STIC was 1.7 mm. In 32 cases (39.5%), the lesion was flat and in 49 (60.5%), papillary. The mean size of flat STICs was 0.8 mm as compared with 2.3 mm for papillary STICs (P=0.00005). STIC was identified in the same tissue fragment as the junction in 48 cases. The mean distance of STIC to the junction was 1.8 mm. In 11 cases, STIC was flanked by peritoneal mesothelium on one side and tubal epithelium on the opposite side. In 51 patients, the mean distance of invasive carcinoma from the TPJ was 1.8 mm. This distance was 1.9 mm when STIC was present (37 cases) in comparison with 1.5 mm when STIC was absent (14 cases) (P not significant). In 27 of 42 cases (64%), STIC was contiguous with invasive carcinoma. Lamina propria invasion was present in 71% of cases in which STIC was present as compared with 26% of cases in which STIC was absent (P<0.0001). Myosalpingeal invasion was present in 40% of cases in which STIC was present as compared with 26% of cases in which STIC was absent (P not significant). It is concluded that serous tubal intraepithelial carcinoma occurs at and in the immediate vicinity of the TPJ. In combination with the findings that STICs are present in a majority of cases when the TPJ is present, that flat STICs are smaller than papillary STICs, and that lamina propria invasion is more frequent in the presence of STIC, these data support STIC as the precursor of extrauterine high-grade serous carcinoma, they provide important clues to the site of origin of high-grade serous carcinoma (ovarian cancer), and can guide further research.

High-Grade serous carcinoma of the fallopian tube: two cases presenting as inguinal lymph node metastasis

Primary fallopian tube high-grade serous carcinoma (HGSCa) has historically been considered an uncommon neoplasm. Recent evidence, however, suggests that most extrauterine HGSCa arise within the fimbriae of the fallopian tube, via an intraepithelial precursor lesion known as serous tubal intraepithelial carcinoma (STIC), which is thought to metastasise to the ovary and pelvic peritoneum. HGSCa typically present with advanced disease and the prognosis is notoriously poor. Presentation of HGSCa as lymph node metastasis is distinctly unusual, even more so in the absence of detectable pelvic disease. We describe two cases of HGSCa of fallopian tube origin presenting as inguinal lymph node metastasis, both with clinically silent pelvic disease at presentation. Although an uncommon mode of presentation, these cases reinforce the need to maintain a high index of suspicion for HGSCa, even in the absence of gynaecological symptoms. Accurate diagnosis is achievable with careful morphological assessment teamed with an immunoperoxidase panel which includes Wilms’ tumour 1 (WT1) and may provide an opportunity for definitive surgery before bulky pelvic disease supervenes. This new model of tumourigenesis of HGSCa may have significant implications for the management of BRCA mutation carriers and potentially all women undergoing pelvic surgery.