Adult Granulosa Cell Tumor With High-grade Transformation: Report of a Series With FOXL2 Mutation Analysis

Adult granulosa cell tumour camouflaged as mucinous neoplasm

This case report delves into the diagnostic intricacies and clinical management of adult granulosa cell tumour (AGCT) in a woman in her 50s, presenting with pain abdomen. Initial imaging investigations like ultrasound suggested diagnosis of benign cystadenoma. Further MRI revealed a large well-defined multiloculated lesion so a diagnosis of neoplastic aetiology/likely mucinous cystadenocarcinoma was offered. However, the definitive diagnosis was established through meticulous histopathological examination, revealing characteristic features of AGCT, a rare ovarian neoplasm. The case underscores the diagnostic challenges posed by AGCT, the importance of integrating clinical, radiological and histopathological data, and the necessity for a multidisciplinary approach for accurate diagnosis and optimal patient management.

Collision Tumor of the Ovary: Adult Granulosa Cell Tumor and Mesonephric-like Adenocarcinoma

Collision tumors of the ovaries are rare, with only a few reports in the literature. Adult granulosa cell tumors are a relatively common primary tumor component of previously reported collision tumors. The combination of serous and mucinous tumors with adult granulosa cell tumors has been reported in several cases. On the other hand, mesonephric-like adenocarcinomas are rare neoplasms that commonly arise in the uterine corpus and ovaries. In this report, we present the case of a collision tumor composed of an adult granulosa cell tumor and mesonephric-like adenocarcinoma of the ovary in a 63-year-old woman. The initial magnetic resonance imaging findings showed a cystic mass with an internal hemorrhage, which suggested an adult granulosa cell tumor, and a solid mass with different enhancements. Microscopically, the tumor had two distinct components: An adult granulosa cell tumor and a mesonephric-like adenocarcinoma. Recognizing collision tumors consisting of slow-growing and aggressive tumors may prove beneficial in future diagnostic and treatment strategies.

Mesonephric-type adenocarcinomas of the ovary: prevalence, diagnostic reproducibility, outcome, and value of PAX2

Mesonephric-type (or -like) adenocarcinomas (MAs) of the ovary are an uncommon and aggressive histotype. They appear to arise through transdifferentiation from Müllerian lesions creating diagnostic challenges. Thus, we aimed to develop a histologic and immunohistochemical (IHC) approach to optimize the identification of MA over its histologic mimics, such as ovarian endometrioid carcinoma (EC). First, we screened 1,537 ovarian epithelial neoplasms with a four-marker IHC panel of GATA3, TTF1, ER, and PR followed by a morphological review of EC to identify MA in retrospective cohorts. Interobserver reproducibility for the distinction of MA versus EC was assessed in 66 cases initially without and subsequently with IHC information (four-marker panel). Expression of PAX2, CD10, and calretinin was evaluated separately, and survival analyses were performed. We identified 23 MAs from which 22 were among 385 cases initially reported as EC (5.7%) and 1 as clear cell carcinoma. The interobserver reproducibility increased from fair to substantial (κ = 0.376-0.727) with the integration of the four-marker IHC panel. PAX2 was the single most sensitive and specific marker to distinguish MA from EC and could be used as a first-line marker together with ER/PR and GATA3/TTF1. Patients with MA had significantly increased risk of earlier death from disease (hazard ratio = 3.08; 95% CI, 1.62-5.85; p < 0.0001) compared with patients with EC, when adjusted for age, stage, and p53 status. A diagnosis of MA has prognostic implications for stage I disease, and due to the subtlety of morphological features in some tumors, a low threshold for ancillary testing is recommended.

Sex Cord-Stromal Tumors of the Ovary: An Update and Review. Part II - Pure Sex Cord and Sex Cord-Stromal Tumors

We review the time honored but still frequently challenging features of ovarian sex cord-stromal tumors and also emphasize new developments, including unusual morphologic appearances that, despite the relative rarity of many of the tumors, result in a disproportionate number of differential diagnostic problems, variant immunohistochemical profiles, and specific molecular and syndromic associations. These neoplasms are also of historical interest as current knowledge is still based in significant part to the contributions of 2 giants of gynecologic pathology, Dr Robert Meyer and Dr. Robert E. Scully. In part I, we reviewed the pure ovarian stromal tumors. Now, in part II, we present the major clinical, pathologic, and genomic features of pure sex cord and sex cord-stromal tumors.

An extensive immunohistochemical analysis of 290 ovarian adult granulosa cell tumors with 29 markers

The current knowledge about the immunohistochemical features of adult granulosa cell tumor (AGCT) is mostly limited to the "traditional" immunohistochemical markers of sex cord differentiation, such as inhibin, calretinin, FOXL2, SF1, and CD99. Knowledge about the immunohistochemical markers possibly used for predictive purpose is limited. In our study, we focused on the immunohistochemical examination of 290 cases of AGCT classified based on strict diagnostic criteria, including molecular testing. The antibodies used included 12 of the "diagnostic" antibodies already examined in previous studies, 10 antibodies whose expression has not yet been examined in AGCT, and 7 antibodies with possible predictive significance, including the expression of HER2, PD-L1, CTLA4, and 4 mismatch repair (MMR) proteins. The results of our study showed expression of FOXL2, SF1, CD99, inhibin A, calretinin, ER, PR, AR, CKAE1/3, and CAIX in 98%, 100%, 90%, 78%, 45%, 41%, 94%, 82%, 26%, and 9% of AGCT, respectively. GATA3, SATB2, napsin A, MUC4, TTF1, and CD44 were all negative. PTEN showed a loss of expression in 71% of cases and DPC4 in 4% of cases. The aberrant staining pattern (overexpression) of p53 was found in 1% (3/268) of cases, 2 primary tumors, and 1 recurrent case. Concerning the predictive markers, the results of our study showed that AGCT is microsatellite stable, do not express PD-L1, and are HER2 negative. The CTLA4 expression was found in almost 70% of AGCT tumor cells.

Relevance of Molecular Pathology for the Diagnosis of Sex Cord-Stromal Tumors of the Ovary: A Narrative Review

Ovarian sex cord-stromal tumors (SCSTs) account for 8% of all primary ovarian neo-plasms. Accurate diagnosis is crucial since each subtype has a specific prognostic and treatment. Apart from fibrosarcomas, stromal tumors are benign while sex cord tumors may recur, sometimes with a significant time to relapse. Although the diagnosis based on morphology is straightforward, in some cases the distinction between stromal tumors and sex cord tumors may be tricky. Indeed, the immunophenotype is usually nonspecific between stromal tumors and sex cord tumors. Therefore, molecular pathology plays an important role in the diagnosis of such entities, with pathognomonic or recurrent alterations, such as FOXL2 variants in adult granulosa cell tumors. In addition, these neoplasms may be associated with genetic syndromes, such as Peutz-Jeghers syndrome for sex cord tumors with annular tubules, and DICER1 syndrome for Sertoli-Leydig cell tumors (SLCTs), for which the pathologist may be in the front line of syndromic suspicion. Molecular pathology of SCST is also relevant for patient prognosis and management. For instance, the DICER1 variant is associated with moderately to poorly differentiated SLCTS and a poorer prognosis. The present review summarizes the histomolecular criteria useful for the diagnosis of SCST, using recent molecular data from the literature.

FOXL2: a gene central to ovarian function

The FOXL2 (forkhead box L2) gene is located on chromosome 3 and encodes for forkhead box (FOX) family of transcription factors which play a critical role in various biological processes. Germline FOXL2 mutations have been identified in blepharophimosis/ptosis/epicanthus inversus syndrome. The somatic missense mutation in FOXL2 (FOXL2 C134W) is now known to be the defining molecular feature of adult-type granulosa cell tumour of the ovary, present in over 90% of cases of this tumour type. Immunohistochemistry for FOXL2 is used as a marker of sex cord-stromal differentiation. However, expression is not restricted to lesions harbouring FOXL2 mutations, and it is positive in a variety of sex cord-stromal proliferations other than adult-type granulosa cell tumour.

Clinicopathological analysis of patients with molecularly confirmed stage I adult granulosa cell tumors and prediction of recurrence

OBJECTIVE

Adult granulosa cell tumors (AGCTs) are rare malignancies that accounts for approximately 1% of ovarian neoplasms. As there are currently no well-recognized models for predicting relapse-free survival (RFS), we performed a clinicopathological analysis to identify risk factors for AGCT recurrence.

METHODS

We investigated 130 patients with pathologically diagnosed AGCT as confirmed by the presence of the characteristic FOXL2 C402G mutation.

RESULTS

Most patients had International Federation of Gynecology and Obstetrics stage I disease (n = 122, 95.3%). The 10-year RFS rate was 31.4% (22/70) and mean 10-year RFS was 74.4 (95% CI, 65.2-83.7) months. Ten patients experienced recurrence beyond the 10-year follow-up period. Undergoing fertility sparing surgery, an estrogen receptor-α (ERα) score (>0.25), and a Ki-67 index >15% were independent risk factors for recurrence in patients with stage I disease (bias-corrected C-index: 0.776). We constructed a nomogram with well-fitting calibration plots; the areas under the curve (AUCs) for 5-, and 10-year RFS prediction were 0.883 and 0.906 respectively. A simplified model with 3 predictive factors (ERα score, Ki-67 index, and primary surgical procedure) and 2 risk stratification subgroups (low- and high-risk) was constructed; its AUCs for 5-, and 10-year RFS prediction were 0.825 and 0.850 respectively. Kaplan-Meier survival curves showed significant differences in 10-year RFS between the low- and high-risk groups (p < 0.001).

CONCLUSIONS

The type of primary surgical procedure, ERα score, and Ki-67 index are independent predictors of recurrence for patients with stage I AGCT. Our predictive model based on these factors showed good performance.

Adult Granulosa Cell Tumour With Heterologous Adipocytic Differentiation: Report of a Unique Case

Adult granulosa cell tumor is the most common malignant ovarian sex cord-stromal tumor and heterologous elements, in the form of hepatocytes or mucinous epithelium, have rarely been described in these neoplasms. Here, we report an adult granulosa cell tumor in a 61-year-old woman with classic and luteinized elements and exhibiting a previously unreported feature in the form of foci of mature adipocytes. In reporting this case, we review heterologous adipocytic elements and other heterologous elements in ovarian sex cord-stromal tumors and speculate on the pathogenesis of the adipocytic differentiation.

p53 as Exemplar Next-Generation Immunohistochemical Marker: A Molecularly Informed, Pattern-Based Approach, Methodological Considerations, and Pan-Cancer Diagnostic Applications

This review is based on a webinar I presented for the International Society for Immunohistochemistry and Molecular Morphology (ISIMM) in February 2022. It is intended that all ISIMM webinars will ultimately be published in AIMM as review articles. This work is also dedicated to Clive Taylor, who has deeply impacted my career. It presents a molecularly informed, pattern-based approach to p53 immunohistochemistry interpretation, methodological considerations (ie, antibody selection, optimization, validation, controls, and external quality assessment), and pan-cancer diagnostic applications, including those drawn from gastrointestinal, genitourinary, gynecological, neuroendocrine, hematologic, and neuropathology. It intends to prove the thesis statement that p53 is an exemplar next-generation immunohistochemical marker "born" ahead of its time.

Update on Ovarian Sex Cord-Stromal Tumors

This article focuses on the recent advances in ovarian sex cord-stromal tumors, predominantly in the setting of their molecular underpinnings. The integration of genetic information with morphologic and immunohistochemical findings in this rare subset of tumors is of clinical significance from refining the diagnostic and prognostic stratifications to genetic counseling.

Adult Granulosa Cell Tumor With Sarcomatous Transformation: A Case Study With Emphasis on Molecular Alterations

Adult granulosa cells tumors (AGCTs) are typically low-grade indolent tumors. On rare occasions, they undergo high-grade/sarcomatous transformation and behave aggressively. This transformation is postulated to occur as the result of acquired genetic alterations, some of which may be eligible for targeted therapy. Here we report a rare case of AGCT with sarcomatous transformation that harbored distinct molecular alterations from those typically seen with AGCTs supporting a molecularly driven approach to these malignancies. The patient is a 56-yr-old G3P3 woman with a history of multiple recurrences of ovarian AGCT for which the first diagnosis was made at the age of 25 when she was evaluated for infertility. The ovarian tumor displayed typical features of AGCT with low-grade, bland morphology. The first extraovarian spread of tumor involving the cul-de-sac was reported at the age of 39. After that, recurrences occurred every 2 to 3 yr with involvement of multiple anatomic sites and repeated surgical resections. At the age of 55 she developed a symptomatic recurrence in the pelvis and underwent resection of an isolated lesion (specimen 1) to no gross residual disease. Within 4 wk of resection she developed significant pelvic pain and imaging showed recurrence of the mass. Therefore, in 5 mo after the initial resection she underwent repeat excision of the lesion (specimen 2) and associated bowel. The sections from specimen 1 showed a biphasic morphology: a low-grade component with morphology and immunophenotype consistent with a typical AGCT and a high-grade spindle cell component with features consistent with a high-grade sarcoma. Specimen 2 featured a pure high-grade sarcoma characterized by coagulative tumor cell necrosis, readily recognizable mitoses, highly atypical cells with vesicular nuclei and prominent nucleoli. SF-1 positivity and the presence of FOXL2 C134W mutation in the sarcomatous component support the notion of transformation of typical AGCT. While detected TERT promoter C228T mutation may play a role in this process, we further identified genetic alterations affecting PI3K/AKT/mTOR pathway, including mutations in PIK3CA , PIK3R1 , AKT1 , and NF2 , which may also contribute to tumor progression/transformation. These findings provide rationale for molecular/pathway-based targeted therapy for patients with advanced AGCT.

Update on Ovarian Sex Cord-Stromal Tumors

This article focuses on the recent advances in ovarian sex cord-stromal tumors, predominantly in the setting of their molecular underpinnings. The integration of genetic information with morphologic and immunohistochemical findings in this rare subset of tumors is of clinical significance from refining the diagnostic and prognostic stratifications to genetic counseling.

Molecular assessment of testicular adult granulosa cell tumor demonstrates significant differences when compared to ovarian counterparts

Testicular adult granulosa cell tumor (AGCT) is a rare type of sex-cord stromal tumor that affects patients of a wide age range and has the potential for late metastasis. In the testis, the diagnosis of AGCTs often requires the exclusion of other more common types of sex-cord stromal tumors. Immunohistochemistry is of limited utility, being used mostly to confirm sex-cord lineage and to exclude other entities when morphology is not typical. Unlike ovarian AGCTs, which are molecularly homogeneous and harbor a specific activating FOXL2 mutation (c.7558C > T p.C134W) in >90% of cases, the molecular characteristics of testicular AGCTs remain largely unknown. In the current study, we analyzed 13 testicular AGCTs diagnosed at multiple institutions using massively parallel DNA sequencing to evaluate single nucleotide variants, copy number alterations, and structural variants. In all, 10/13 cases were sequenced successfully. Notably, the FOXL2 c.7558C > T (p.C134W) mutation was identified in only a single case (1/10, 10%). The remaining cases were molecularly heterogeneous, with largely nonrecurrent genetic variants. Putative driver events in individual cases included a well-characterized gain-of-function NRAS mutation, as well as inactivation of ATM and TP53, among others. The only highly recurrent finding was single copy loss of 22q (7/10 cases, 70%). Comparatively, the frequencies of FOXL2 c.7558C > T (p.C134W) and 22q loss in 12 metastatic ovarian AGCTs identified in our database were 92% (11/12) and 42% (5/12), respectively. The results of the present study suggest that testicular AGCTs are different from their ovarian counterparts in that they appear to be molecularly heterogeneous and only rarely harbor FOXL2 mutations.

High-grade Transformation in Adult Granulosa Cell Tumor: Potential Diagnostic Challenges and the Utility of Molecular Testing

Adult granulosa cell tumor (AGCT) is the most common sex cord-stromal tumor, accounting for about 1% of all ovarian tumors. It has a propensity for recurrences, especially late in the disease course. High-grade or sarcomatoid transformation has been rarely described in AGCT. We present a case of a 65 year old woman who presented with hemodynamic shock and bowel obstruction from a large pelvic mass. Histologic examination revealed predominantly high-grade epithelioid and spindled cells with high mitotic activity and necrosis. A minor component suggestive of AGCT was also identified. Molecular analysis confirmed the diagnosis of AGCT by revealing FOXL2 C134W mutations. Additionally, TP53 mutations were also detected which may contribute to the high-grade transformation. Our case is unique because the high-grade sarcomatous component constituted most of the tumor and the areas of "typical" AGCT were minor. Also, the clinical and operative findings did not suggest a specific site of origin leading to a broad differential diagnosis. High-grade transformation in AGCT is a rarely described phenomenon. The awareness of this presentation is helpful in reaching the correct diagnosis. Molecular analysis may be an extremely helpful adjunct in challenging cases.

A complex case of a granulosa cell tumour

This is a case of a 73-year-old woman who first presented in 2020 with a fullness in her abdomen. After several thorough investigations and unforeseen complications, the fullness was diagnosed as a granulosa cell tumour. In 2003, she had been diagnosed with a granulosa cell tumour of the ovary. Complete excision was performed, however she was not given a follow-up appointment after the procedure. This case highlights the importance of frequent follow-up of these tumours, the high recurrence rate, the severe complications which may result and the awareness of possible variations in this tumour's histologic appearance.

Ovarian Low-grade Basaloid Carcinoma Arising in Brenner Tumor: A New Variant of Malignant Brenner Tumor

Brenner tumors are uncommon ovarian neoplasms, most of which are benign, although borderline and malignant variants occur. We report 2 unusual ovarian neoplasms composed of an admixture of typical benign Brenner tumor and a low-grade epithelial neoplasm which we designate as low-grade basaloid carcinoma. The latter component morphologically and immunohistochemically resembled "salivary gland-type/myoepithelial" neoplasms with variable positive staining with cytokeratins, p63, S100, and CD117. One tumor exhibited aggressive behavior with local recurrence and distant metastasis. This neoplasm exhibited focal "high-grade" transformation with diffuse mutation-type p53 staining, in contrast to the wild-type immunoreactivity in the low-grade component. As far as we are aware, such neoplasms have not previously been reported in the literature and this represents a newly described morphologic variant of malignant Brenner tumor.

Rare DICER1 and Absent FOXL2 Mutations Characterize Ovarian Juvenile Granulosa Cell Tumors

FOXL2 somatic mutation occurs in a high percentage of ovarian adult granulosa cell tumors and DICER1 mutations in a high proportion of Sertoli-Leydig cell tumors. These mutations have only been studied in a limited number of juvenile granulosa cell tumors (JGCTs), and their occurrence and frequency in these neoplasms is controversial. We aimed to determine the frequency of FOXL2 and DICER1 mutations in a large cohort of 50 JGCTs, and to evaluate the prognostic impact of these mutations. A FOXL2 hotspot mutation was found in 2/50 JGCTs. Review of these 2 cases reclassified them as adult granulosa cell tumors. Thus, FOXL2 mutation was absent from our large cohort of JGCTs. DICER1 mutations in the RNase IIIb domain were found in 4 cases. After review of the mutated cases, 1 was reclassified as a gynandroblastoma with a prominent JGCT component. Thus, DICER1 mutations were detected in 3/47 (6%) of pathologically confirmed JGCTs. Our results show that FOXL2 mutations are not present in JGCT, whereas a small percentage of these neoplasms exhibit DICER1 mutations.

p53 immunohistochemical analysis of fusion-positive uterine sarcomas

AIMS

Uterine sarcomas can be grouped into tumours with pathognomonic genetic fusions such as low-grade endometrial stromal sarcoma (LGESS), high-grade endometrial stromal sarcoma (HGESS), and inflammatory myofibroblastic tumour (IMT), and tumours lacking genetic fusions such as leiomyosarcoma (LMS) and undifferentiated uterine sarcoma (UUS). Members of the latter group frequently harbour TP53 mutations. The aim of this study was to evaluate TP53 mutations by the use of immunohistochemistry in fusion-positive uterine sarcomas.

METHODS AND RESULTS

We performed p53 immunohistochemical staining on 124 uterine sarcomas harbouring genetic fusions and 38 fusion-negative LMSs and UUSs. These included 41 HGESSs with YWHAE, BCOR and BCORL1 fusions/rearrangements, 13 IMTs with ALK fusion, 12 sarcomas with NTRK1/3 fusion, three sarcomas with PDGFB fusion, and 55 LGESSs with JAZF1, SUZ12 and PHF1 fusions/rearrangements. All HGESSs, LGESSs, IMTs and sarcomas with PDGFB fusion showed wild-type p53 expression. Among NTRK1/3-positive sarcomas, a TPR-NTRK1-positive sarcoma with nuclear pleomorphism showed mutation-type p53 expression. The remaining 11 NTRK1/3-positive sarcomas showed wild-type p53 expression, except for the subclonal p53 mutation-type staining in a minor pleomorphic focus of an NTRK3-positive sarcoma. Twenty-one of 27 (78%) LMSs and six of nine (67%) UUSs showed mutation-type p53 expression.

CONCLUSION

p53 immunohistochemistry may be considered in the initial work-up of a uterine sarcoma, as mutation-type staining would make a fusion-positive sarcoma very unlikely. Mutation-type p53 expression, however, can be seen in a small subset of NTRK1/3-positive sarcomas showing pleomorphic round/ovoid cell histology, which may represent a mechanism of progression in these tumours.

The Many Uses of p53 Immunohistochemistry in Gynecological Pathology: Proceedings of the ISGyP Companion Society Session at the 2020 USCAP Annual9 Meeting

Ancillary immunohistochemistry (IHC) has become a reliable adjunct for subclassification of gynecological neoplasms. An important recent development was optimization and validation of p53 IHC, where 3 abnormal IHC patterns (nuclear overexpression, complete absence, cytoplasmic) were shown to predict underlying TP53 mutations with high accuracy in ovarian carcinomas. p53 IHC now helps in distinguishing high-grade serous from low-grade serous carcinomas. Thereafter, the new interpretation of p53 IHC was quickly adapted for other purposes and similar accuracies were shown in endometrial carcinomas, vulvar squamous cell carcinomas, and ovarian mucinous tumors. However, it required further refinement of the p53 IHC interpretation criteria for each tumor site. A proportion of endometrial endometrioid carcinomas shows an ultramutated or hypermutated genotype due to underlying POLE mutations or mismatch repair deficiency sometimes causing subclonal TP53 mutations, and their distribution can be visualized by p53 IHC. Squamous cell carcinomas and ovarian mucinous tumors show a phenomenon called terminal differentiation where basal cells demonstrate an abnormal pattern of p53 IHC but apical cells do not despite an underlying TP53 mutation. High-grade progression of adult granulosa cell tumors due to a subclonal TP53 mutation has been recently described. Another use of p53 IHC is triaging gynecological sarcomas for molecular testing based on the assumption that TP53-mutated gynecological sarcomas do not harbor cancer driving translocations. Therefore, familiarity with interpretation of p53 IHC is becoming increasingly important for the practicing gynecological pathologist. Furthermore, local optimization of the p53 IHC assay using validated protocols including appropriate low expressing control tissues (eg, tonsil) is vital in order to achieve high diagnostic accuracy, especially for abnormal staining patterns such as complete absence or cytoplasmic, and interlaboratory concordance. p53 IHC is a reliable diagnostic adjunct for histotyping and molecular subtyping of ovarian and endometrial carcinomas, and it paves the way for large-scale studies to validate the prognostic value of p53 IHC in several gynecological tumor types. The technical advances, validated interpretation criteria, and its growing versatility in identifying high-risk neoplasms paired with its widespread availability in pathology departments make p53 IHC perhaps the single most useful IHC stain in gynecological pathology.

Development of pathological reconstructed high-resolution images using artificial intelligence based on whole slide image

Pathology plays a very important role in cancer diagnosis. The rapid development of digital pathology (DP) based on whole slide image (WSI) has led to many improvements in computer-assisted diagnosis by artificial intelligence. The common digitization strategy is to scan the pathology slice with 20× or 40× objective, and the 40× objective requires excessive storage space and transmission time, which are significant negative factors in the popularization of DP. In this article, we present a novel reconstructed high-resolution (HR) process based on deep learning to switch 20 × WSI to 40 × without the loss of whole and local features. Furthermore, we collected the WSI data of 100 uterine leiomyosarcomas and 100 adult granulosa cell tumors to test our reconstructed HR process. We tested the reconstructed HR WSI by the peak signal-to-noise ratio, structural similarity, and the blind/reject image spatial quality evaluator, which were 42.03, 0.99, and 49.22, respectively. Subsequently, we confirmed the consistency between the actual and our reconstructed HR images. The testing results indicate that the reconstructed HR imaging is a reliable method for the digital slides of a variety of tumors and can be available on a large scale in clinical pathology as an innovative technique.

Undifferentiated and dedifferentiated neoplasms of the female genital tract

Undifferentiated neoplasms in the female gynecologic tract comprise two main groups-undifferentiated carcinoma, most common in the endometrium and ovary, and undifferentiated uterine sarcoma, although tumors with an undifferentiated appearance may occur in all gynecologic organs. Their differential diagnosis is broad and generous sampling, careful morphological evaluation, judicious use of immunohistochemistry, and in many cases, molecular testing is often essential in the diagnostic work-up. As some of these neoplasms fail to respond to conventional chemotherapy regimens and/or radiation therapy, targeted therapy may be valuable in treating these highly aggressive tumors, thus the importance of precise diagnosis. In this review we discuss the clinicopathological features of undifferentiated carcinoma, dedifferentiated carcinoma, and undifferentiated uterine sarcoma, followed by a comprehensive analysis of morphological mimickers. Finally, we briefly review ovarian and lower genital tract tumors with an undifferentiated histological appearance.

Evaluation of molecular analysis in challenging ovarian sex cord-stromal tumours: a review of 50 cases

Molecular profiling was performed in 50 problematic ovarian sex cord-stromal tumours (SCSTs) most of which were seen in consultation. Following analysis, 17 were classified as adult granulosa cell tumour (AGCT), 16 of which showed a FOXL2 sequence variant (mutation); the initial favoured diagnosis in five of the cases was benign thecoma/fibrothecoma. Thirteen tumours ultimately classified as cellular fibroma or thecoma were FOXL2 sequence variant negative which was helpful in excluding AGCT. All six Sertoli-Leydig cell tumours (SLCTs) demonstrated DICER1 'hot spot' sequence variants, and one case each of AGCT and SLCT showed high grade histological transformation associated with a concurrent TP53 sequence variant. All eight unclassified SCSTs were negative for FOXL2 mutations and the six tested cases were DICER1 wild type; however, three tumours demonstrated MET, CTNNB1 or TP53 sequence variants. Four cases were classified as juvenile granulosa cell tumour, and one of these harboured a GNAS sequence variant. The single gynandroblastoma and microcystic stromal tumours in the series demonstrated FOXL2 and CTNNB1 alterations, respectively. In summary, molecular analysis aids in accurate classification of challenging ovarian SCSTs and sometimes leads to revision of the favoured provisional diagnosis. TP53 sequence variants may be associated with dedifferentiation in both SLCTs and AGCTs.

Whole Genome Analysis of Ovarian Granulosa Cell Tumors Reveals Tumor Heterogeneity and a High-Grade TP53-Specific Subgroup

Adult granulosa cell tumors (AGCTs) harbor a somatic FOXL2 c.402C>G mutation in ~95% of cases and are mainly surgically removed due to limited systemic treatment effect. In this study, potentially targetable genomic alterations in AGCTs were investigated by whole genome sequencing on 46 tumor samples and matched normal DNA. Copy number variant (CNV) analysis confirmed gain of chromosome 12 and 14, and loss of 22. Pathogenic TP53 mutations were identified in three patients with highest tumor mutational burden and mitotic activity, defining a high-grade AGCT subgroup. Within-patient tumor comparisons showed 29-80% unique somatic mutations per sample, suggesting tumor heterogeneity. A higher mutational burden was found in recurrent tumors, as compared to primary AGCTs. FOXL2-wildtype AGCTs harbored DICER1, TERT(C228T) and TP53 mutations and similar CNV profiles as FOXL2-mutant tumors. Our study confirms that absence of the FOXL2 c.402C>G mutation does not exclude AGCT diagnosis. The lack of overlapping variants in targetable cancer genes indicates the need for personalized treatment for AGCT patients.

FOXL2 homozygous genotype and chromosome instability are associated with recurrence in adult granulosa cell tumors of the ovary

Introduction: Adult granulosa cell tumors (aGCTs) are extremely rare tumors characterized by the presence of the single missense mutation (c.402 C>G, p. C134W) in the FOXL2 gene. These tumors are frequently associated with a slow, indolent disease progression and a high probability of aggressive tumor recurrence. Hence, the identification of molecular markers that are predictive of recurrence and/or aggressive behavior would be a great asset in the management of aGCT. The present study focused on the influence of the FOXL2 genotype (heterozygous or homozygous) and copy number variations (CNVs) in recurrence by comparing the primary tumor with recurrent lesions in the same patient. We performed array comparative genomic hybridization (CGH) experiments and FOXL2 genotyping by allelic discrimination on 40 tumor samples. Results and Discussion: In array CGH results of recurrent tumors, few samples presented the multiple chromosome losses and gains characteristic of chromosome instability (CIN). We also observed that three recurrent tumors and one primary tumor appeared to be homozygous for the FOXL2 c.402C>G mutation. Interestingly, the homozygous FOXL2 genotype was correlated with a shorter time to relapse. A change in the FOXL2 genotype in cases of recurrence was correlated with the appearance of CIN. Conclusion: Despite the small number of matching primary and recurrent tumors analyzed here, the present study is the first to have shown that the FOXL2 homozygous genotype and CIN are prevalent in recurrent aGCTs. The two mechanisms are probably linked, and both almost certainly have a role in the molecular transformation of aGCTs.

Ovarian tumors: a survey of selected advances of note during the life of this journal

The author reviews highlights of advances in knowledge concerning ovarian tumor pathology since the time of an essay in the first issue of this Journal written by Dr Robert E. Scully, who, both before and for several decades after the Journal was instituted, made many original contributions to the field and was the major architect of the 1973 World Health Organization classification of ovarian tumors which was much more clear and logical than prior ones. The current review considers the neoplasms in essentially the same order as was done in the first issue of this journal and presents a personal look at the highlights of new information concerning various well-known categories, surface epithelial, germ cell, sex cord-stromal, metastatic neoplasms and briefly, benign so-called tumor-like lesions. Some of the most notable developments are as follows: (1) an orderly approach to the classification of implants of serous borderline tumors into noninvasive and invasive categories; (2) recognition of distinctive micropapillary patterns seen in some borderline tumors and low-grade carcinomas; (3) a remarkable propensity for some endometrioid carcinomas to mimic sex cord- stromal tumors; (4) appreciation of the differences between primary mucinous tumors of intestinal and müllerian types; (5) the importance of distinguishing within primary mucinous carcinomas between expansile and destructive stromal invasion; (6) emphasis on the diagnosis of immature teratoma being based on the presence of primitive-embryonic-appearing tissues; (7) appreciation of variant morphology of cases of struma ovarii which may lead to significant diagnostic problems; (8) subdivision of granulosa cell tumors into adult and juvenile types because of the differing features of the two groups including in the second category the propensity for more malignant neoplasms to be mimicked; (9) recognition of a distinctive form of Sertoli-Leydig cell tumor, the retiform variant, with a propensity to occur in the young; (10) appreciation of a unique highly malignant neoplasm that typically afflicts the young and may be associated with hypercalcemia, so-called small cell carcinoma of hypercalcemic type; (11) greater awareness than was hitherto the case of the propensity for metastatic intestinal adenocarcinoma to mimic primary endometrioid carcinoma and similarly for metastatic mucinous carcinomas to simulate primary mucinous cystic tumors; (12) recognition of the distinctive features of low-grade appendiceal mucinous neoplasms that spread to the ovary and are typically associated with pseudomyxoma peritonei; and (13) appreciation that the histologic spectrum seen in cases of Krukenberg tumor is broader than often previously thought.