BCOR Expression in Mullerian Adenosarcoma: A Potential Diagnostic Pitfall

Diagnostic Value of Combined BCOR, Cyclin D1, and CD10 in Differentiating Endometrial Stromal Sarcoma From Other Uterine Spindle cell Lesions

Uterine spindle cell lesions share a dilemmatic overlapped features that needed to be addressed by the pathologist to reach a conclusive accurate diagnosis for its prognostic value and different management decisions. Usage of combined IHC panel can be an aiding guiding tool in this context. The aim of this study is to evaluate the diagnostic value of combined BCOR, Cyclin D1, and CD10 IHC panel in differentiating endometrial stromal sarcoma from other uterine spindle cell lesions. This study included 60 cases categorized into endometrial stromal sarcoma group (ESS) (12 cases high-grade endometrial stromal sarcoma [HGESS] and 18 cases low-grade endometrial stromal sarcoma [LGESS]), malignant uterine spindle cell lesions group (5 cases adenosarcoma [AS], 6 cases leiomyosarcoma [LS], 4 cases carcinosarcoma [CS]), and benign uterine lesions group (5 cases endometrial stromal nodule [ESN], 5 cases leiomyoma, and 5 cases adenomyosis). IHC staining procedure and evaluation for BCOR, Cyclin D1, and CD10 was performed on all studied cases. BCOR IHC staining was positive in all HGESS (12/12) of ESS group cases, with diffuse pattern in 75% of cases. BCOR-diffuse staining pattern was not recorded in any of LGESS (0/18), malignant mesenchymal lesions group (0/15), and also benign lesions group (0/15). Cyclin D1 positivity was observed only in HGESS cases, in parallel with positive-BCOR expression. On the contrary, CD10 was negatively expressed in all HGESS and positive in all LGESS, ESN, and adenomyosis cases. A specificity of 100% and sensitivity of 75% were recorded in differentiating HGESS from malignant mesenchymal lesions (including LMS, AS, and CS) and also HGESS from LGESS when using the combined panel BCOR+ve D/Cyclin D1+ve / CD10-ve, considering only the BCOR-diffuse staining pattern. In conclusion, BCOR+ve D/Cyclin D1+ve/CD10-ve as a combined panel is 100% specific and with lesser sensitivity in diagnosing HGESS as well as differentiating it from LGESS and other malignant uterine spindle cell lesions.

An Unusual Endometrial Stromal Neoplasm With JAZF1-BCORL1 Rearrangement

Endometrial stromal tumors represent the second most common category of uterine mesenchymal tumors. Several different histologic variants and underlying genetic alterations have been recognized, one such being a group associated with BCORL1 rearrangements. They are usually high-grade endometrial stromal sarcomas, often associated with prominent myxoid background and aggressive behavior. Here, we report an unusual endometrial stromal neoplasm with JAZF1-BCORL1 rearrangement and briefly review the literature. The neoplasm formed a well-circumscribed uterine mass in a 50-yr-old woman and had an unusual morphologic appearance that did not warrant a high-grade categorization. It was characterized by a predominant population of epithelioid cells with clear to focally eosinophilic cytoplasm growing in interanastomosing cords and trabeculae set in a hyalinized stroma as well as nested and fascicular growths imparting focal resemblance to a uterine tumor resembling ovarian sex-cord tumor, PEComa, and a smooth muscle neoplasm. A minor storiform growth of spindle cells reminiscent of the fibroblastic variant of low-grade endometrial stromal sarcoma was also noted but conventional areas of low-grade endometrial stromal neoplasm were not identified. This case expands the spectrum of morphologic features seen in endometrial stromal tumors, especially when associated with a BCORL1 fusion and highlights the utility of immunohistochemical and molecular techniques in the diagnosis of these tumors, not all of which are high grade.

Evaluation of Lineage/Site-specific Nuclear Immunohistochemical Markers SATB2, Cyclin D1, SALL4, and BCOR in High-grade Endometrial Carcinomas

Poorly differentiated malignant neoplasms involving the gynecologic tract routinely include a poorly differentiated endometrial carcinoma (EC) in the differential diagnosis. Some nuclear lineage/site-specific immunohistochemical markers are utilized in this diagnostic setting including SATB2, cyclin D1, SALL4, and BCOR, but their specificity and use in small samples are not clear across the spectrum of ECs. Cases of undifferentiated/dedifferentiated endometrial carcinomas (UEC/DDEC), clear cell carcinoma (CCC), uterine serous carcinoma (USC), FIGO grade 3 endometrial endometrioid carcinoma (EEC), and uterine carcinosarcoma (UCS) were identified and diagnoses confirmed. Whole-section immunohistochemical stains for SATB2, cyclin D1, SALL4, BCOR, and PAX8 were performed. A total of 113 cases were utilized: 15 CCC, 26 EEC, 19 UCS, 22 USC, and 31 UEC/DDEC. Cases were distributed across both low (49%) and high (51%) FIGO clinical stages. SATB2 was expressed by UCS (8/19, 42%), EEC (10/26, 38%), UEC/DDEC (11/30, 37%), and USC (6/22, 27%). Cyclin D1 was expressed by EEC (24/26, 92%), USC (17/22, 77%), UEC/DDEC (15/20 EEC component, 75%; 22/30 UEC, 73%), UCS (10/16 carcinoma, 63%; 11/19 sarcoma, 58%), and CCC (8/15, 53%). SALL4 was expressed most frequently by UEC/DDEC (12/30, 40%), but also USC (7/22, 32%), EEC (5/26, 19%), and UCS (4/16 carcinoma, 25%; 3/19 sarcoma, 16%). BCOR was expressed at low levels in 2 USC, 2 UEC/DDEC, and 2 UCS. PAX8 was generally positive but showed lower expression in UEC/DDEC (17/30, 57%) and in the sarcomatous portions of UCS (6/19, 32%). SATB2, cyclin D1, SALL4, and BCOR stain variable numbers of poorly-differentiated EC and must be carefully interpreted within morphologic and clinical context.

An Unusual Benign Uterine Stromal Spindle Cell Tumor Harboring JAZF1::BCORL1

Uterine mesenchymal lesions demonstrate various underlying genomic alterations involving MED12 , JAZF1 , YWHAE , BCOR , and ALK genes, among others. Recent publications describe a subset of high-grade endometrial stromal sarcoma lesions harboring BCORL1 gene aberrations including JAZF1::BCORL1 . Herein, we present an unusual benign endomyometrial spindle cell lesion that defies classificatory efforts by demonstrating mixed histomorphologic and immunohistochemical features of endometrial stromal nodule, leiomyoma, and uterine inflammatory myofibroblastic tumor while harboring a JAZF1::BCORL1 . The lesion was found in a 43-yr-old woman with pelvic pain and heavy menses as a 5.5 cm well-circumscribed ulcerated mass fungating from the cervical os. Microscopic examination revealed a polypoid, well-circumscribed, moderately cellular endomyometrial tumor composed by bland spindle cells haphazardly disposed within a slightly edematous stroma enriched by a delicate network of thin-walled vessels that were occasionally encircled by the tumor cells. Unequivocal evidence of tongue-like growth pattern into the myometrium, tumor-type necrosis or increased mitotic activity was not identified after sampling the entire lesion. The lesion showed patchy immunoreactivity for both smooth muscle actin-alpha and desmin while negative for CD10, HMB45, ALK (D5F3), and BCOR. An Archer FusionPlex panel assay demonstrated a fusion involving both exons 4 from the JAZF1 and BCORL1 genes. The JAZF1::BCORL1 has not, to the best of our knowledge, been previously reported in a benign/low-grade mesenchymal uterine lesion.

Differential diagnosis of uterine adenosarcoma: identification of JAZF1-BCORL1 rearrangement by comprehensive cancer genomic profiling

BACKGROUND

Uterine adenosarcoma is a rare malignant tumor that accounts for 8% of all uterine sarcomas, and less than 0.2% of all uterine malignancies. However, it is frequently misdiagnosed in clinical examinations, including pathological diagnosis, and imaging studies owing to its rare and non-specific nature, which is further compounded by the lack of specific diagnostic markers.

CASE PRESENTATION

We report a case of uterine adenosarcoma for which a comprehensive genomic profiling (CGP) test provided a chance to reach the proper diagnosis. The patient, a woman in her 60s with a history of uterine leiomyoma was diagnosed with an intra-abdominal mass post presentation with abdominal distention and loss of appetite. She was suspected to have gastrointestinal stromal tumor (GIST); the laparotomically excised mass was found to comprise uniform spindle-shaped cells that grew in bundles with a herringbone architecture, and occasional myxomatous stroma. Immunostaining revealed no specific findings, and the tumor was diagnosed as a spindle cell tumor/suspicious adult fibrosarcoma. The tumor relapsed during postoperative follow-up, and showed size reduction with chemotherapy, prior to regrowth. CGP was performed to identify a possible treatment, which resulted in detection of a JAZF1-BCORL1 rearrangement. Since the rearrangement has been reported in uterine sarcomas, we reevaluated specimens of the preceding uterine leiomyoma, which revealed the presence of adenosarcoma components in the corpus uteri. Furthermore, both the uterine adenosarcoma and intra-abdominal mass were partially positive for CD10 and BCOR staining.

CONCLUSION

These results led to the conclusive identification of the abdominal tumor as a metastasis of the uterine adenosarcoma. The JAZF1-BCORL1 rearrangement is predominantly associated with uterine stromal sarcomas; thus far, ours is the second report of the same in an adenosarcoma. Adenosarcomas are rare and difficult to diagnose, especially in atypical cases with scarce glandular epithelial components. Identification of rearrangements involving BCOR or BCORL1, will encourage BCOR staining analysis, thereby potentially resulting in better diagnostic outcomes. Given that platinum-based chemotherapy was proposed as the treatment choice for this patient post diagnosis with adenosarcoma, CGP also indirectly contributed to the designing of the best-suited treatment protocol.

ZC3H7B-BCOR High-Grade Endometrial Stromal Sarcoma with a Mucoid Grossly Feature: A Case Report and Literature Review

We report on a 50-year-old postmenopausal woman who presented with abnormal uterine bleeding and pelvic pain due to a uterine solid mass grew from the uterine fundus to the cervix and with so far undescribed obviously gelatinous grossly change, which was suspected of myxoid leiomyosarcoma in intraoperative diagnosis. Morphologically, the tumor cells displayed haphazard fascicles of uniform mild-to-moderate heteromorphic spindle cell component with significant and abundant myxoid stroma, forming signet ring cells and microcysts. Immunohistochemically, the tumour cells were diffusely positivefor CD10 and cyclin D1 and negative for Desmin and SMA, but the expression of BCOR staining was not present. The FISH study showed a positive BCOR gene break probe, and the RNA sequencing revealed an identified reciprocal fusion gene ZC3H7B-BCOR. The case was finally diagnosed as ZC3H7B-BCOR high-grade endometrial stromal sarcoma. Tumor recurrence occurred rapidly on the pelvic peritoneal and vaginal 2 months after resection. In conclusion, these findings further support ZC3H7B-BCOR HGESS has a poor prognosis and molecular testing of uterine mesenchymal tumors with myxoid matrix and unusual grossly presentation is recommended to avoid misdiagnosis.

Endometrial Stromal Sarcomas With BCOR Internal Tandem Duplication and Variant BCOR/BCORL1 Rearrangements Resemble High-grade Endometrial Stromal Sarcomas With Recurrent CDK4 Pathway Alterations and MDM2 Amplifications

The distinction between low-grade and high-grade endometrial stromal sarcomas (LGESS, HGESS) is increasingly defined by genetics. Recently, variant genomic alterations involving BCOR or BCORL1 have been reported in endometrial stromal sarcoma (ESS), although it remains unclear whether these justify a diagnosis of LGESS or HGESS. In this study, we describe clinicopathologic and molecular features of ESS with such alterations to help clarify their classification in the spectrum of ESS. We collected a cohort of 13 ESS harboring variant alteration involving BCOR (6 with internal tandem duplication, 1 with EP300::BCOR fusion, 1 with BCOR::LPP fusion) and BCORL1 ( 4 with JAZF1::BCORL1 fusion, 1 with EPC1::BCORL1 fusion). The median patient age at primary diagnosis was 51 years (range: 18 to 70 y). Median tumor size at primary diagnosis was 9.3 cm (range: 4.5 to 21 cm), and extrauterine disease spread (stage IIIB-C) was present in 27%. The tumors were composed of round to spindled cells with cellularity and cytologic atypia ranging from mild to marked and a median mitotic count of 18/10 HPFs (range: 2 to 85/10 HPFs). At least focally myopermeative growth was noted in 8/8 assessable cases. Of 12 patients with follow-up data (median: 25 mo), 4 patients died of disease and 3 were alive with recurrent disease. Unsupervised hierarchical clustering of DNA methylation data together with a large cohort of uterine mesenchymal tumors that included YWHAE::NUTM2 and Z C3H7B::BCOR HGESS and molecularly confirmed LGESS revealed a common methylation signature for all ESS with variant BCOR and BCORL1 alterations and HGESS with YWHAE::NUTM2 and ZC3H7B::BCOR gene fusion. Copy number analysis revealed amplifications of CDK4 and MDM2 , as well as homozygous deletions of CDKN2A/B and NF1 in a subset of tumors. Our results indicate that ESS with BCOR internal tandem duplication and variant BCOR and BCORL1 rearrangements clinically and molecularly resemble conventional HGESS.

Diffusely infiltrating glioma with CREBBP-BCORL1 fusion showing overexpression of not only BCORL1 but BCOR: A case report

BCORL1 encodes a transcriptional corepressor homolog to BCOR. BCORL1 rearrangements have been previously described as rare events, and among them, CREBBP-BCORL1 has been reported only in 2 cases of ossifying fibromyxoid tumors. Herein, we present the first case of diffusely infiltrating glioma with CREBBP-BCORL1 involving a 17-year-old female patient. Histologically, the tumor was composed of a diffusely infiltrative proliferation of small tumor cells with moderate cellularity showing prominent microcystic formation. DNA methylation analysis revealed that the current case and a previously reported anaplastic ependymoma with EP300-BCORL1 were clustered together in close proximity to but distinct from methylation class high-grade neuroepithelial tumor with BCOR alteration. RNA sequencing demonstrated high mRNA expression of not only BCORL1 but BCOR, and the latter was compatible with diffuse nuclear expression of BCOR detected by immunohistochemistry. Our findings suggest that central nervous system tumors with CREBBP/EP300-BCORL1 may exhibit diverse morphologies but form a distinct DNA methylation group and that BCORL1 fusion genes may lead to upregulation of both BCOR and BCORL1.

High-grade Endometrial Stromal Sarcoma: Morphologic and Clinical Features, the Role of Immunohistochemistry and Fluorescence in Situ Hybridization in Diagnosis

Introduction. High-grade endometrial stromal sarcomas (HGESS) are rare malignant mesenchymal tumors of the uterus with aggressive poor clinical outcome, which frequently exhibit YWHAE::NUTM2 and ZC3H7B::BCOR fusions. In this study, we aimed to investigate HGESSs with YWHAE and BCOR translocations through our archive materials, and to identify morphological, immunohistochemical and molecular features of these tumors. We also assessed the diagnostic value of BCOR immunohistochemistry (IHC) in HGESSs, low-grade endometrial stromal sarcomas (LGESS) and uterine leiomyosarcomas. Methods. One hundred fifty-one uterine sarcomas diagnosed between 2000-2019 were reevaluated, and tumors of 39 patients with specific features were included in the study. Fluorescence in situ hybridization (FISH) studies using YWHAE and BCOR break-apart probes and BCOR IHC were performed. BCOR IHC was also performed in 20 leiomyosarcomas and 19 LGESSs. Results. In six HGESSs, translocations involving YWHAE or BCOR were detected. Five tumors showed high-grade morphology and revealed YWHAE translocation. One HGESS with myxoid morphology revealed BCOR translocation. In immunohistochemistry, three (3/4) YWHAE translocated HGESSs showed BCOR expression. However, the BCOR translocated HGESS was BCOR negative. The study showed that all LGESSs were immunohistochemically negative with BCOR. Although 15% (3/20) leiomyosarcomas reveal focal weak-moderate BCOR expression. Conclusion. BCOR IHC is a useful marker to distinguish LGESS from HGESS. A small percentage of uterine leiomyosarcomas reveal BCOR expression; however, it is not as diffuse and strong as in HGESSs. Strong and diffuse BCOR IHC expression is highly suggestive for HGESS. The diagnosis of HGESS should be supported by molecular studies such as FISH.

Primary Fallopian Tube Mullerian Adenosarcoma With Sarcomatous Overgrowth and a Previously Unreported MEIS1-NCOA2 Gene Fusion

Extrauterine Mullerian adenosarcomas (MA) are rare and often associated with endometriosis. We report a 55-yr-old patient seen in consultation for abdominal pain and bloating. Imaging was suggestive of a left adnexal mass and "peritoneal carcinomatosis". Pathological examination of the specimen revealed a MA arising in the left fallopian tube, with sarcomatous overgrowth, diffuse peritoneal involvement and omental "caking". Next-generation sequencing identified a MEIS1-NCOA2 gene fusion, previously unreported in MA.

Clinicopathological and genomic characterization of BCORL1-driven high-grade endometrial stromal sarcomas

BCORL1 is a transcriptional corepressor homologous to BCOR. We describe 12 BCORL1-altered uterine sarcomas with striking resemblance to BCOR-altered endometrial stromal sarcoma (BCOR-ESS), including 5 with BCORL1 rearrangements (JAZF1-BCORL1, EP300-BCORL1, or internal BCORL1 rearrangement), 5 with inactivating BCORL1 mutations (T513fs*22, P600fs*1, R945*, R1196*, or R1265fs*4) and 2 with homozygous BCORL1 deletion. The median patient age was 57.5 years (range 33-79). An association with aggressive clinical behavior was identified. Diagnoses assigned prior to genomic testing varied: 7 tumors were previously diagnosed as ESS, 2 as high-grade uterine sarcomas, 2 as myxoid uterine leiomyosarcomas, and 1 as a uterine spindle cell neoplasm consistent with leiomyosarcoma. Tumors harbored frequent gelatinous, mucomyxoid-like appearance by gross examination and unique histology with morphological overlap with BCOR-ESS. Key microscopic features included (1) a spindle cell appearance, most often with at least focal myxoid stroma, (2) variable amounts of hypocellular fibromyxoid spindle areas with lower grade atypia and/or (3) variable amounts of epithelioid areas with higher grade atypia. Specifically, spindle and epithelioid components were present in 100 and 75% of sarcomas, respectively; myxoid stroma was identified in 83%, collagen plaques or fibrosis in 50%, and high-grade nuclear atypia was present in 42%. Like BCOR-ESS, 50% of BCORL1-altered sarcomas exhibited CDK4 amplification or CDKN2A loss. In contrast, 33% harbored NF1 alterations, while 25% had other alterations in the NF2-mTOR pathway, expanding potential therapeutic targets. In conclusion, inactivating BCORL1 genomic alterations may define a distinct subset of high-grade endometrial stromal sarcomas with biological overlap with BCOR-ESS, both of which may mimic myxoid leiomyosarcomas.

Meta-analysis of BCOR rearranged sarcomas: challenging the therapeutic approach

INTRODUCTION

BCOR rearranged sarcomas comprise a group of malignant mesenchymal tumors that until recently were classified as Ewing sarcomas or as undifferentiated round cell sarcomas. The identification of alterations involving BCOR gene such as BCOR-CCNB3, BCOR-MAML3, ZC3H7B-BCOR fusion genes and BCOR internal tandem duplication (ITD) is characteristic for the differential diagnosis of BCOR rearranged sarcomas. Due to the rarity of these tumors there is no consensus or guidelines regarding the optimal therapeutic algorithm, that clinicians should follow.

PATIENTS AND METHODS

Herein we have conducted a meta-analysis of the current reports dealing with the therapeutic approach of BCOR rearranged sarcomas.

RESULTS

Meta-analysis of the 57 eligible cases from 10 studies resulted to similar Incidence Rate Ratio (IRR) and overall survival (OS) for patients who received Ewing protocols and non-Ewing oriented treatment. Further similar death rate was reported for both strategies (non-Ewing 20% Vs Ewing 21.8%).

CONCLUSION

Our data support that non-Ewing treatment strategy can be considered a safe option, being at least equal to Ewing protocols. The current study provides a hint toward the optimal therapeutic approach of BCOR rearranged sarcomas. Further, the present study challenges the use of the term Ewing-like sarcomas, since the current literature supports that BCOR rearranged sarcomas deserve their own distinct classification in terms of genetics, pathology and therapy.

Targeted RNA expression profiling identifies high-grade endometrial stromal sarcoma as a clinically relevant molecular subtype of uterine sarcoma

High-grade endometrial stromal sarcoma (HGESS) may harbor YWHAE-NUTM2A/B fusion, ZC3H7B-BCOR fusion, and BCOR internal tandem duplication (ITD). NTRK3 upregulation and pan-Trk expression were reported in soft tissue lesions that share similar morphology and genetic abnormalities. To confirm these findings in HGESS, differential expression analysis was performed at gene level comparing 11 HGESS with 48 other uterine sarcomas, including 9 low-grade endometrial stromal sarcomas, 23 undifferentiated uterine sarcomas, and 16 leiomyosarcomas, using targeted RNA sequencing data. Pan-Trk immunohistochemistry was performed on 35 HGESS, including 10 tumors with RNA expression data, with genotypes previously confirmed by targeted RNA sequencing, fluorescence in situ hybridization, and/or genomic PCR. Unsupervised hierarchical clustering of the top 25% of differentially expressed probes identified three molecular groups: (1) high NTRK3, FGFR3, RET, BCOR, GLI1, and PTCH1 and low ESR1 expression; (2) low NTRK3, FGFR3, RET, BCOR, GLI1, and PTCH1 and high ESR1 expression; and (3) low NTRK3, FGFR3, RET, BCOR, GLI1, PTCH1, and ESR1 expression. Among HGESS, 64% of tumors clustered in group 1, while 27% clustered in group 2. Cytoplasmic and/or nuclear pan-Trk staining of variable extent and intensity was seen in 91% of HGESS regardless of cyclin D1 and/or BCOR positivity. ER and PR expression was seen in 44% of HGESS despite ESR1 downregulation. Two patients with ER and PR positive but ESR1 downregulated stage I HGESS were treated with endocrine therapy, and both recurred at 12 and 36 months after primary resection. By RNA expression, HGESS appear homogenous and distinct from other uterine sarcomas by activation of kinases, including NTRK3, and sonic hedgehog pathway genes along with downregulation of ESR1. Most HGESS demonstrate pan-Trk staining which may serve as a diagnostic biomarker. ESR1 downregulation is seen in some HGESS that express ER and PR which raises implications in the utility of endocrine therapy in these patients.

BCOR-CCNB3 Sarcoma with Prominent Rhabdoid Cells Mimicking Rhabdomyoblasts: Expanding the Morphologic spectrum of BCOR-CCNB3 Sarcoma

BCOR-CCNB3 sarcoma (BCS) is a rare recently defined undifferentiated sarcoma that predominantly affects children and young adults. The diagnosis of this tumor is difficult due to the highly variable morphology and nonspecific immunophenotype. Emerging data suggest that patients with BCS show response to Ewing sarcoma-based treatment regimen, thus correct diagnosis is of clinical relevance. In this study, we report a case of BCS arising from the big toe of a 15-year-old male patient. The tumor had a prominent population of rhabdoid cells with bright eosinophilic cytoplasm mimicking rhabdomyosarcoma. The tumor cells were focally positive for desmin and myogenin, and negative for CD99. Next-generation sequencing showed the presence of BCOR-CCNB3 gene fusion. BCS with prominent rhabdoid cells has not been described before. This study further expands the morphologic spectrum of BCS.

Molecular pathogenesis and prognostication of "low-grade'' and "high-grade" endometrial stromal sarcoma

Endometrial stromal sarcomas (ESS) are a heterogeneous group of rare mesenchymal cancers. Considerable knowledge has been gained in recent years about the molecular characteristics of these cancers, which helps to classify them in a more meaningful manner leading to improved diagnosis, prognostication, and treatment. According to this classification, ESS is now grouped as low‐ or high‐grade. ESS may have overlapping clinical presentation, morphology, and immunohistochemical profile. Their genetic characteristics allow subdivision of many of them depending on which pathogenetically important fusion genes they carry, but clearly much more needs to be unraveled in this regard. We here provide an overview of the molecular pathogenetic knowledge gained so far on low‐ and high‐grade ESS.

Immunohistochemical markers and the clinical course of adenosarcoma: a series of seven cases

Background

Uterine adenosarcoma, a rare uterine tumor subtype, is a biphasic tumor consisting of epithelial and mesenchymal elements. To date, there is no research comparing the histopathological features and immunohistochemistry of primary and recurrent tumors; furthermore, the relationship between pathology and the clinical course remains unclear. We reviewed the pathology and immunohistochemical features of patients with adenosarcoma and investigated the relevance of the histomorphological features to the clinical course. We also compared the immunohistochemical features of the primary and recurrent tumors.

Methods

The data of seven patients with adenosarcoma who underwent surgery in our hospital were evaluated. We performed immunohistochemical staining for the progesterone receptor, estrogen receptor, p53, and two Switch/Sucrose Non-Fermentable chromatin remodeling proteins (SMARCA4, BCOR), which were recently developed for the undifferentiated sarcoma diagnosis in addition to conventional staining methods.

Results

All patients had International Federation of Gynecology and Obstetrics stage IB–IC diseases. All tumors were polypoid and every patient presented with abnormal uterine bleeding. Six patients aged over 50 years and were menopausal; one patient aged under 50 years and was non-menopausal (average age: 59.1 years). Histologically, the sarcomatous components were homologous and heterogenous in six and one patient, respectively. Four and three cases were recurrent and non-recurrent, respectively. The recurrent patients showed high-grade morphology with sarcomatous overgrowth and were negative for ER and PR. Three recurrences could be evaluated by imaging, showing recurrence only in a distant area; biopsy specimens from these tissues revealed the identical mesenchymal component found in the primary tumor without a benign epithelial component. Immunohistochemical staining results were also similar to the corresponding of the original tumor, except for the p53 expression in one patient. At the primary site, p53 was overexpressed in two recurrent patients and had a wild-type level in one recurrent patient; however, all three recurrent tissues showed p53 overexpression. None of our patients showed SMARCA4 loss, and BCOR expression was positive in one case.

Conclusions

Initial pathological adenosarcoma analysis with appropriate immunohistochemical staining is vital for prognostic assessment. p53 expression might increase at recurrence. SMARCA4 and BCOR might not be an index of malignancy.