Hypercalcemia is a frequent complication of solid tumors and hematologic malignancies yet is only rarely associated with endometrial clear cell carcinoma. Here we report on a 70-year-old female who presented in the context of hip fracture and was incidentally found to have humoral hypercalcemia of malignancy secondary to endometrial clear cell carcinoma. This rare association makes endometrial cancer one of the differential diagnoses to be considered when assessing incidentally found symptomatic or asymptomatic hypercalcemia in the appropriate patient population.

BACKGROUND: The main cause of vocal cord palsy (VCP) is idiopathic impairment of the recurrent laryngeal nerve (RLN). However, solid tumors along the pathway of the RLN can also impact the nerve\'s function. We presented a patient with a thyroid lesion and VCP due to a bulky metastatic mass (uterine cancer) on the aortic arch field in the mediastinum. The report aims to show the significance of comorbid tumors in thyroid pathology and the importance of additional diagnostic methods in avoiding unnecessary surgeries. A patient\'s lifetime and the outcome of the disease were also presented.
METHODS: A 58-year-old Ukrainian woman with a hoarse voice, intermittent dry cough, and weakness was presented to an endocrine surgeon. Thyroid pathology included signs of hypothyroidism treated with Thyroxine 112.5 µg and a nodule in the left lobe. The lesion is located on the posterior aspect of the lobe, which could probably be a cause of RLN involvement. Fine needle aspiration biopsy (FNAB) was performed twice with Bethesda category 2 result. Fibrolaryngoscopy (FLS) revealed the median position of the left vocal cord. Idiopathic, laryngeal, and thyroid causes of the VCP were excluded. Additionally, the patient displayed her anamnesis of the endometrial clear cell carcinoma following hysterectomy, external beam radiation therapy, and chemotherapy. The mediastinal metastasis was revealed sixteen years later. A chest computed tomography (CT) with intravenous contrast was done. A bulky tumor was found right under the aortic arch. Subsequently, the voice complaints reduced significantly after 4 chemotherapy courses. Cancer progression had led to the appearance of lymph node metastases on the supraclavicular region. Following six months the 60-year-old patient had passed away.
CONCLUSIONS: A history of the disease should always be kept in mind when assessing a patient\'s complaints. VCP in case of thyroid pathology and previous secondary malignancy may be caused by metastatic tumor anywhere along the RLN pathway. Such a rare case shows the importance of additional methods of examination which may avoid unnecessary thyroid surgeries.

UNASSIGNED: The aim of this study was to verify TCGA subtypes in endometrial clear cell carcinoma (ECCC) and determine their clinical and molecular characteristics.
UNASSIGNED: We summarized and compared the clinical features of 28 clear cell carcinoma and 112 endometrioid carcinoma patients. Of the 28 ECCCs, 19 underwent TCGA classification, and other markers (ER, PR, ARID1A, ARIB1B, TAF1, and HER-2) were also detected by IHC, and outcomes were assessed.
UNASSIGNED: Compared to endometrioid carcinoma, ECCC had an older age of onset (median age, 64.5 years, range 31-81 years), higher rate of myometrial invasion (42.8% vs. 21.5% in endometrioid carcinoma), LVSI (33% vs. 16%), and more advanced FIGO stage. Among the ECCCs, LVSI was a poor prognostic factor. TCGA classification was performed for 19 ECCCs: two POLEmut cases (10.5%), three MMRd (15.8%), 11 p53wt (57.9%), and three p53abn (15.8%). Of the 19 ECCCs, six (31.6%) showed HER-2 positive expression, and eight (42.1%) had TAF1 expression loss. ECCCs possessed HER-2 and TAF1 expression had worse outcomes.
UNASSIGNED: Our study summarized the clinical features of ECCC. The outcomes of patients with ECCC with TCGA subtypes differed from those of patients with endometrioid carcinoma. HER-2 and TAF1 may be new prognostic factors.

HER2 (ERBB2) overexpression and/or HER2 gene amplification has been well established in several tumors types and when present HER2 directed therapy may be to be efficacious. While recent findings suggests that HER2 overexpression and HER2 amplification are a relatively common in serous endometrial carcinoma, similar data regarding clear cell endometrial carcinoma (CCC) is difficult to interpret due to issues such as diagnostic criteria, sample type and HER2 interpretation criteria. Our goals were to study HER2 expression and HER2 copy number status in hysterectomy specimens from a large series of patients with pure CCC to determine the frequency of HER2 overexpression and HER2 amplification and evaluate applicability of current HER2 interpretation criteria. Pure CCC specimens derived from hysterectomy specimens from 26 patients were identified. All diagnoses were confirmed by two gynecologic pathologists. Immunohistochemistry for HER2 protein and fluorescence in situ hybridization (FISH) studies for HER2 were performed on whole-slide sections from all cases. Results were interpreted according to the 2018 ASO/CAP HER2 guidelines for breast cancer and International Society of Gynecologic Pathologists (ISGyP) HER2 guidelines for serous endometrial carcinoma. Additional testing was performed when indicated by the guidelines. HER2 expression by immunohistochemistry was 3+ in 4% and 0% of cases, and 2+ in 46% and 52% of cases, by 2018 ASCO/CAP and ISGyP criteria, respectively, while the remaining cases were negative. HER2 testing by FISH showed a positive result in 27% of tumors with 2018 ASCO/CAP guidelines, while 23% were positive with the ISGyP criteria. Our findings indicate that HER2 overexpression and HER2 amplification occur in a subset of CCC. Therefore, additional study into the potential benefit of HER2 targeted therapy in patients with CCC is warranted.

Metastasis to the breast from extra-mammary malignancies are rare, accounting for less than 1% of all breast cancers. Endometrial cancer, a common gynecological malignancy, often spreads to the pelvis, abdominal lymph nodes, peritoneum or the lungs. Endometrial metastasis to the breast is extremely rare, and while there have been isolated case reports of endometrial serous carcinoma with breast metastasis, it has not been reported in the case of clear cell carcinoma. We present a rare case of a 70 year old Chinese lady who had a metastatic endometrial clear cell carcinoma with metastasis to the breast, mimicking an inflammatory breast cancer clinically. We reviewed the current literature and describe the challenges in differentiating primary from metastatic breast lesions, as well as clinical, radiological and histopathological features that may help to differentiate the two. Tumour metastasis to the breast via lymphatic or hematogenous route can affect their radiological features: the former mimicking inflammatory breast cancer and the latter with features similar to benign breast lesions. Regardless, histological features with immunohistochemical staining is still the gold standard in diagnosing metastatic breast lesions and determining their tissue of origin. Breast metastases from extra-mammary malignancies are uncommon and it is even rarer for endometrial clear cell carcinoma to spread to the breast. Nonetheless, this case highlights the importance of keeping an open mind and engaging a multidisciplinary team for the care of complex patients.

BACKGROUND: Clear cell carcinoma is an uncommon histologic subtype of ovarian and endometrial carcinoma with poor response to Platinium-based chemotherapy agents at high stages. Blockage of Programmed cell Death Ligand-1 (PD-L1), can be used in targeted immunotherapy. This study investigated Mismatch Repair Deficiency (MMR-D) status, PD-L1 expression, and the correlation between PD-L1 expression and microsatellite instability (MSI) status in ovarian and endometrial clear cell carcinomas.
METHODS: Ovarian clear cell carcinoma (OCCC) (n = 28) and endometrial clear cell carcinoma (ECCC) (n = 28) samples were evaluated for PD-L1 (in tumoral and peri-tumoral inflammatory cells), MSH6 and PMS2 expression by immunohistochemistry (IHC) study. PD-L1 expression > 1% in tumor cells and > 5% in peritumoral inflammatory cells were considered positive.
RESULTS: The prevalence of PD-L1 expression was higher in ECCC (20/28, 71.43%) compared to OCCC tumor cells (16/28, 57.15%) (p > 0.05), while expression in peritumoral inflammatory cells was significantly higher in ECCC (25/28, 89.29%) compared to OCCC (11/28, 39.28%) (p < 0.05). MMR-D was observed in 5 cases, four OCCCs and one ECCC, among which, four (80%) showed PD-L1 expression in peritumoral inflammatory and tumor cells. The only OCCC case with extensive PD-L1 expression in tumor cells (> 50%) exhibited MSH6/MSH2 loss. No significant correlation was noted between PD-L1 expression and the pathologic stage or survival.
CONCLUSIONS: PD-L1 expression was significantly associated with clear cell morphology, especially in the endometrium, independent of MMR protein status.

UNASSIGNED: A systematic analysis of prognostic factors concerning endometrial clear cell carcinoma (ECCC) is lacking. The current study aimed to construct nomograms predicting the overall survival (OS) of ECCC patients.
UNASSIGNED: We performed a retrospective study, and predicted nomograms for 3-, 5-, and 10-year OS were established. The nomograms were verified with the consistency index (C-index), calibration curve, and decision curve analysis (DCA).
UNASSIGNED: A total of 1778 ECCC patients, 991 from FIGO stage I/II and 787 from FIGO stage III/IV, were included in this study. The age at diagnosis, marital status, T stage, tumor size, and surgery-independent prognostic factors in FIGO stage I/II, and the age at diagnosis, T stage, lymph node involvement, distant metastasis, tumor size, surgery, radiotherapy, and chemotherapy in FIGO stage III/IV were independent prognostic factors. The C-indexes of the training and validation group were 0.766 and 0.697 for FIGO stage I/II and 0.721 and 0.708 for FIGO stage III/IV, respectively. The calibration curve revealed good agreement between nomogram-predicted and actual observation values. The DCA established that nomograms had better clinical benefits than the traditional FIGO stage.
UNASSIGNED: The predicted nomograms showed good accuracy, excellent discrimination ability, and clinical benefits, depicting their usage in clinical practice.

BACKGROUND: The balance of pro- and anti-apoptotic proteins plays a critical role in the regulation of cell death, and a disruption of this delicate balance may eventuate in carcinogenesis through a net reduction in apoptosis. Numerous chemotherapeutic strategies directly or indirectly target apoptotic pathways. However, a thorough assessment of apoptosis-related proteins has not previously been performed in endometrial clear cell carcinoma (CCC). This study aims to determine the significance of 9 apoptosis-related proteins in the pathogenesis of CCC as compared to non-neoplastic endometrium (NNE), low- and high-grade endometrial endometrioid carcinomas (LG-EEC, HG-EEC), and endometrial serous carcinoma (ESC).
METHODS: Expression of 6 anti-apoptotic proteins (Bcl-2, Bcl-xL, cFLIPL, MCL-1, survivin, NFκB/p65) and three pro-apoptotic proteins (Bax, caspase-3, caspase-8) was assessed by immunohistochemistry on 49 CCC, 37 LG-EEC, 12 HG-ECC, 16 ESC, and 25 NNE in a tissue microarray. Objective IHC scores were assigned by an automated image capture system. Scores were then correlated with clinicopathologic values and each other.
RESULTS: Most notably, CCC showed significantly reduced expression of cFLIPL relative to ESC, LG-EEC, HG-EEC, and NNE. CCC also showed significantly reduced expression of both Caspase 8 and NF-κB/p65 relative to ESC, HG-EEC, and NNE, but not LG-EEC. Bcl-2 and Bcl-xL showed reduced expression in CCC relative to all groups except ESC for Bcl-2 and NNE for Bcl-xL. There was no significant correlation between the proteins regarding expression levels. Within the CCC group, none of the proteins showed any significant association with patient age, myometrial invasion, final stage, lymphovascular invasion, disease-free or overall survival.
CONCLUSIONS: Our analysis of the expression and correlation patterns of a panel of apoptosis-related proteins suggests that the downregulation of cFLIPL in CCC is significant relative to almost all other tissues, NNE, HG-EEC, and ESC. Other proteins, including Caspase 8, NF-κB/p65, Bcl-2 and Bcl-xL may also be significant. The regulation of apoptosis-related proteins in CCC may be important and may provide insight into chemoresistance in this enigmatic histotype. However, the paradoxical downregulation of both pro- and anti-apoptotic mediators suggests that additional study is needed to clarify the role of apoptotic mechanisms in CCC.

Clear cell carcinoma of the endometrium is a rare type of endometrial cancer that is generally associated with an aggressive clinical behaviour. Here, we sought to define the repertoire of somatic genetic alterations in endometrial clear cell carcinomas (ECCs), and whether ECCs could be classified into the molecular subtypes described for endometrial endometrioid and serous carcinomas. We performed a rigorous histopathological review, immunohistochemical analysis and massively parallel sequencing targeting 300 cancer-related genes of 32 pure ECCs. Eleven (34%), seven (22%) and six (19%) ECCs showed abnormal expression patterns for p53, ARID1A, and at least one DNA mismatch repair (MMR) protein, respectively. Targeted sequencing data were obtained from 30 of the 32 ECCs included in this study, and these revealed that two ECCs (7%) were ultramutated and harboured mutations affecting the exonuclease domain of POLE. In POLE wild-type ECCs, TP53 (46%), PIK3CA (36%), PPP2R1A (36%), FBXW7 (25%), ARID1A (21%), PIK3R1 (18%) and SPOP (18%) were the genes most commonly affected by mutations; 18% and 11% harboured CCNE1 and ERBB2 amplifications, respectively, and 11% showed DAXX homozygous deletions. ECCs less frequently harboured mutations affecting CTNNB1 and PTEN but more frequently harboured PPP2R1A and TP53 mutations than non-POLE endometrioid carcinomas from The Cancer Genome Atlas (TCGA). Compared to endometrial serous carcinomas (TCGA), ECCs less frequently harboured TP53 mutations. When a surrogate model for the molecular-based TCGA classification was used, all molecular subtypes previously identified in endometrial endometrioid and serous carcinomas were present in the ECCs studied, including POLE, MMR-deficient, copy-number high (serous-like)/p53 abnormal, and copy-number low (endometrioid)/p53 wild-type, which were significantly associated with disease-free survival in univariate analysis. These findings demonstrate that ECCs constitute a histologically and genetically heterogeneous group of tumours with varying outcomes. Furthermore, our data suggest that the classification of ECCs as being generally \'high-grade\' or \'type II\' tumours may not be warranted. Copyright © 2017 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

The expression of α-methylacyl-coenzyme-A racemase (AMACR) has previously been reported in 75% to 100% of urethral/bladder clear cell carcinomas, tumors that are known to display broad phenotypic overlap with their identically named müllerian counterparts. Herein, we assess the utility of AMACR in distinguishing endometrial clear cell carcinomas (CCCs) from endometrial serous carcinomas (ESCs) and endometrial endometrioid carcinomas (EECs). A total of 111 endometrial carcinomas in a tissue microarray, including 49 CCCs, 13 ESCs, and 49 EECs, were assessed for AMACR immunoreactivity, with results scored semiquantitatively (scores 0, 1+, 2+, 3+ for 0%, 1%-5%, 6%-50%, >50% immunoreactive cells, respectively). Fifty (45%) of the 111 carcinomas were AMACR positive, with the following score distribution: CCC: 0 (n = 12), 1+ (n = 12), 2+ (n = 3), 3+ (n = 22); EEC: 0 (n = 38), 1+ (n = 4), 2+ (n = 4), 3+ (n = 3); ESC: 0 (n = 11), 1+ (n = 1), 2+ (n = 0), 3+ (n = 1). AMACR expression was significantly more frequent in CCC (75%) than in ESC (15%) or EEC (22%); P < .0001. The sensitivity and specificity of AMACR expression in classifying a carcinoma as CCC were 0.75 (95% confidence interval [CI], 0.61-0.86) and 0.79 (95% CI, 0.66-0.88), respectively, with an odds ratio of 11.62 (95% CI, 5-28; P < .001) and an area under the curve of 0.79 (95% CI, 0.68-0.88). These findings indicate that AMACR expression is strongly associated with CCC and displays a relatively robust diagnostic test performance. However, its practical utility may be limited by the focal nature of its expression in 32% of the AMACR-positive CCC cases as well as its expression in 15% to 22% of the non-CCC histotypes.