Clear Cell Renal Cell Carcinoma With Syncytial-Type Multinucleated Giant Tumor Cells: A Clinicopathologic Study of 14 Cases

The presence of syncytial-type multinucleated giant tumor cells with emperipolesis in clear cell renal cell carcinoma (RCC) is uncommon, with only 31 cumulative published cases to date. After a rereview of 125 clear cell RCC of World Health Organization/International Society of Urological Pathology grade 3 or 4, 14 clear cell RCCs with admixed syncytial-type giant cells (to our knowledge, the largest series to date) were found with a mean patient age of 67 years and with no sex difference (M = 7, F = 7). Mean tumor size was 7.3 cm. The syncytial-type giant cells comprised between 2% and 20% of the tumor and were present mainly around areas of necrosis. Five tumors were staged as pT1 or pT2, 8 as pT3, and 1 as pT4. Other findings included sarcomatoid differentiation (3/14), rhabdoid differentiation (4/14), and emperipolesis (12/14). Positive immunostains included keratin AE1/AE3 (13/13), carbonic anhydrase 9 and CD10 (12/14 each), vimentin (8/14), EMA (5/12), and alpha-methyacyl-CoA racemase (3/12). Keratin 7, keratin 20, human melanoma black 45, KIT, TFE3, cathepsin K, CD68, CD61, and beta human chorionic gonadotropin were negative. Six of 13 patients had recurrence or metastases during a mean follow-up time of 56 months. Four of 13 patients died of disease, 2 of 13 patients were alive with the disease, and 7 of 13 patients had no evidence of disease. Although the incidence of finding syncytial-type multinucleated giant tumor cells in clear cell RCC is low (approximately 1.2%), given that a subset of the patients showed poor outcomes while lacking other poor histologic parameters (eg, sarcomatoid or rhabdoid differentiation), it may be prudent to recognize and report this feature when encountered.

Vascular, adipose tissue, and/or calyceal invasion in clear cell tubulopapillary renal cell tumour: potentially problematic diagnostic scenarios

AIMS

The 2022 WHO classification for kidney tumours recently downgraded clear cell tubulopapillary (also known as clear cell papillary) renal cell carcinoma (RCC) to a benign neoplasm (i.e. clear cell tubulopapillary renal cell tumour) based on the overwhelmingly banal nature of this neoplasm. However, it has been recognized that some clear cell tubulopapillary renal cell tumours demonstrate vascular, adipose or pelvicalyceal invasion, raising the possibility of more aggressive behaviour. The goal of this study was to determine if these 'high stage' features have an effect on tumour prognosis, warranting a carcinoma designation.

METHODS AND RESULTS

After excluding cases with tissue artefact (i.e. prior core biopsy track changes) and other RCC subtypes with next-generation sequencing, nine clear cell tubulopapillary renal cell tumours with these so-called 'high stage' features, and otherwise classic morphologic and immunophenotypic findings, including low-grade cytology and 'cup-like' CA9 expression, were evaluated. Median tumour size was 2.2 cm with a range of 0.8 to 6.7 cm. Eight cases (89%) demonstrated perinephric or hilar adipose tissue invasion, although most of these cases showed a bulging (in contrast to an infiltrative) growth pattern. One case demonstrated renal vascular invasion in addition to hilar adipose tissue invasion, and one case demonstrated extension into the pelvicalyceal system. There were no recurrences or evidence of metastatic disease.

CONCLUSION

These overall findings continue to support the benign designation for clear cell tubulopapillary renal cell tumours, despite morphologic features that might raise the possibility of a 'higher stage' neoplasm.

Top advances of the year: Ovarian cancer

Although cure rates remain low and effective screening strategies are elusive, the recent advances in systemic therapies over the past year highlighted in this review have prolonged survival for women with ovarian cancer. In 2022, the first antibody-drug conjugate for platinum-resistant ovarian cancer received accelerated US Food and Drug Administration (FDA) approval. Confirmatory studies examining the efficacy of mirvetuximab and other antibody-drug conjugates are underway. In the upfront setting, the first data establishing an overall survival benefit from poly(ADP-ribose) polymerase inhibitor maintenance was demonstrated after a 7-year follow-up period. In contrast, long-term updates from poly(ADP-ribose) polymerase inhibitor trials in the noncurative setting reported survival detriments, and the FDA withdrew the respective indications. Several trials attempted to improve upon the standard of care for platinum-sensitive ovarian carcinoma and those with rare ovarian cancer histologies (carcinosarcoma, clear cell carcinoma) but failed to demonstrate a clinically or statistically meaningful benefit. This leaves the open question of how to further optimize systemic therapy for advanced ovarian carcinoma to improve long-term survival and cure rates.

Unveiling lipid-rich ("clear cell") pancreatic neuroendocrine tumor: A small series of two cases with literature review

This study presents two cases of lipid-rich pancreatic neuroendocrine tumors (PanNETs), a rare variant posing significant diagnostic challenges in fine needle aspiration (FNA) cytology and small biopsies. The first case involves an elderly male with a pancreatic tumor, displaying distinct cytoplasmic vacuoles, while the second case is a middle-aged male present with a pancreatic tail mass exhibiting foamy cytoplasm and eccentric nuclei, infiltrating in the stroma. Both cases did not exhibit typical morphologic features of PanNET but demonstrated cytomorphologic features and infiltrative growth patterns that mimicked adenocarcinoma. Further work-up demonstrated that both tumors were immunoreactive for synaptophysin and chromogranin, and were interpreted as well-differentiated, PanNET, lipid-rich variant. The study highlights the overlapping morphological features between lipid-rich PanNETs and other pancreatic neoplasms and underscores the importance of comprehensive cytological and immunohistochemical analysis for accurately diagnosing this variant, particularly due to the risk of misinterpreting it as pancreatic adenocarcinoma. Recognizing lipid-rich PanNETs is crucial for appropriate clinical management, as their identification can significantly impact treatment decisions and patient outcomes.

Clinicopathological and molecular features of renal cell carcinomas with haemangioblastoma-like features distinct from clear cell renal cell carcinoma

AIMS

Haemangioblastomas arise in the central nervous system. Rarely, haemangioblastomas may develop in extra-neural sites, such as the kidneys. A few reported cases of renal cell carcinomas (RCCs) with haemangioblastoma-like features have exhibited both clear cell renal cell carcinoma (CCRCC)- and haemangioblastoma-like components. The clinicopathological and molecular characteristics of RCCs with haemangioblastoma-like features were analysed, focusing on VHL alterations, in comparison with CCRCCs partially resembling haemangioblastoma.

METHODS AND RESULTS

Four RCCs with haemangioblastoma-like features and five CCRCCs partially resembling haemangioblastoma were included. The RCCs with haemangioblastoma-like features were indolent and lacked adverse prognostic factors. All RCCs with haemangioblastoma-like features had a well-circumscribed appearance and a thick fibromuscular capsule, with fibromuscular bundles extending into the tumour to varying degrees in the three tumours. Each RCC with haemangioblastoma-like features exhibited CCRCC-like areas with indistinct tubular structures and foci of haemangioblastoma-like areas, in which vessels and short spindle cells overwhelmed tumour cells. Whereas haemangioblastoma-like areas in the CCRCCs partially resembling haemangioblastoma exhibited sparse vessels and spindle cells and distinct clear cells. The RCCs with haemangioblastoma-like features exhibited a unique immunohistochemical profile, with positive staining for inhibin-α, S100, carbonic-anhydrase-9, keratin7, and high molecular weight keratin and negative staining for (alpha-methylacyl-CoA racemase) AMACR. RCC with haemangioblastoma-like features did not display any VHL alterations, including VHL mutation, 3p LOH, and methylation of the VHL promoter region, and the two tumours harboured a likely oncogenic missense variant of MTOR (c.7280T>G).

CONCLUSION

The histopathological, immunohistochemical, and molecular findings suggest that RCC with haemangioblastoma-like features is a distinct entity from CCRCC.

Atypical Histopathological Aspects of Common Types of Lung Cancer-Our Experience and Literature Review

Lung cancer is among the most common oncological diseases regarding incidence and mortality, with most of these having epithelial origins. Pathological reporting of these tumors is conducted according to the 5th edition of the World Health Organisation (WHO) classification of thoracic tumours. This study aims to draw the pathologist's attention to four rare, atypical microscopic aspects that some of the most common types of lung malignancies reveal upon standard evaluation (hematoxylin-eosin stain) that make histopathological diagnosis challenging: acantholytic, pseudoangiosarcomatous, signet ring cell, and clear cell features. Each of these aspects was exemplified by a case diagnosed in the pathology department of the "Marius Nasta" Institute. Furthermore, we analyzed the classification dynamics of different WHO editions and used PubMed to review articles written in English and published in the last eleven years on this subject. Pathologists should be familiar with these unusual aspects to avoid misdiagnoses and to ensure the correct classification of tumors, which is extremely important because these tumor phenotypes have been associated with specific molecular alterations and a worse clinical evolution. There is a need to clarify the histogenesis and associated genetic mutations, given the fact that the rarity of these tumor phenotypes makes their study difficult. Some authors consider these to be overlapping entities; however, we do not encourage this, as they may exhibit different prognoses and various molecular alterations with important therapeutic implications. The signet ring cell feature was associated with ALK rearrangement in lung adenocarcinoma; thus, these patients can benefit from tailored therapy with ALK-tyrosine kinase inhibitors (ALK-TKI). Recent studies associated clear cell morphology with FGFR3-TACC3 fusion, suggesting that patients with this diagnosis may be potentially eligible for FGFR inhibitors. We described, for the first time, the pseudoangiosarcomatous pattern in a case of lung adenocarcinoma; to our knowledge this aspect has only been described until now in the context of squamous cell carcinomas.

Mesonephric-like adenocarcinoma harbours characteristic copy number variations and a distinct DNA methylation signature closely related to mesonephric adenocarcinoma of the cervix

Mesonephric-like adenocarcinoma (MLA) of the female genital tract is an uncommon histotype that can arise in both the endometrium and the ovary. The exact cell of origin and histogenesis currently remain unknown. Here, we investigated whole genome DNA methylation patterns and copy number variations (CNVs) in a series of MLAs in the context of a large cohort of various gynaecological carcinoma types. CNV analysis of 19 MLAs uncovered gains of chromosomes 1q (18/19, 95%), 10 (15/19, 79%), 12 (14/19, 74%), and 2 (10/19, 53%), as well as loss of chromosome 1p (7/19, 37%). Gains of chromosomes 1q, 10, and 12 were also identified in the majority of mesonephric adenocarcinomas of the uterine cervix (MAs) as well as subsets of endometrioid carcinomas (ECs) and low-grade serous carcinomas of the ovary (LGSCs) but only in a minority of serous carcinomas of the uterine corpus (USCs), clear cell carcinomas (CCCs), and tubo-ovarian high-grade serous carcinomas (HGSCs). While losses of chromosome 1p together with gains of chromosome 1q were also identified in both MA and LGSC, gains of chromosome 2 were almost exclusively identified in MLA and MA. Unsupervised hierarchical clustering and t-SNE analysis of DNA methylation data (Illumina EPIC array) identified a co-clustering for MLAs and MAs, which was distinct from clusters of ECs, USCs, CCCs, LGSCs, and HGSCs. Group-wise comparisons confirmed a close epigenetic relationship between MLA and MA. These findings, in conjunction with the established histological and immunophenotypical overlap, suggest bona fide mesonephric differentiation, and support a more precise terminology of mesonephric-type adenocarcinoma instead of MLA in these tumours. © 2023 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Clinical Outcome and Morphology-Based Analysis of p53 Aberrant and Mismatch Repair Protein-Deficient Ovarian Clear Cell Carcinoma and Their Association With p16, HER2, and PD-L1 Expression

OBJECTIVES

We studied the prevalence and prognostic significance of mismatch repair deficient (MMRD) and p53 aberrant ovarian clear cell carcinoma (CCO) and their association with other prognostic and theranostic biomarkers (p16, HER2, PD-L1). We also aimed to identify morphologic features to serve as screening tools for immunohistochemical testing for these biomarkers.

METHODS

Tissue microarrays with 3-mm cores from 71 pure CCOs were immunostained with PMS2, MSH6, p53, p16, HER2, and PD-L1. Expression status was correlated with tumor recurrence/disease progression and survival. It was also correlated with morphologic features (tumor size, nuclear grade, tumor architecture, mitotic activity, presence of endometriosis, tumor budding, and tumor inflammation).

RESULTS

p53 aberrant tumors were associated with shorter overall and recurrence-free survivals (P = .002 and P = .01, respectively). In multivariate analysis, p53 aberrant status and tumor stage were independently associated with recurrence/disease progression (hazard ratio [HR] = 3.31, P = .037 and HR = 1.465, P = .004, respectively). p53 aberrant status was associated with tumor budding (P = .037). MMRD, p16, HER2, and PD-L1 expression had no prognostic significance. HER2 and PD-L1 were expressed in 56% and 35% of tumors, respectively. MMRD was associated with tumor expression of PD-L1 (P > .05) but not with tumor inflammation.

CONCLUSIONS

Aberrant p53 in CCO is infrequent but associated with poor prognosis independent of stage. Presence of tumor budding could be a screening tool for p53 testing. High prevalence of HER2 and PD-L1 expression indicates the eligibility of patients with CCO for ongoing clinical trials using these therapeutic targets.

Mixed Endometrial Epithelial Carcinoma: Epidemiology, Treatment and Survival Rates-A 10-Year Retrospective Cohort Study from a Single Institution

Mixed endometrial carcinoma (MEEC) refers to rare endometrial tumours that are composed of two or more distinct histotypes, at least one of which is serous or clear cell. The aim of this study was to evaluate the epidemiology, treatment outcomes and survival rates of patients with mixed endometrial carcinoma. The medical records of 34 patients diagnosed with MEEC between March 2010 and January 2020 were reviewed retrospectively. Clinicopathological variables and treatment strategies were assessed, and overall survival and disease-free survival rates were evaluated. The histology of endometrioid and serous component was found in 26 (76.5%) patients, followed by serous and clear-cell components (5/34, 14.5%) and mixed endometrioid serous and clear-cell components (3/34, 8.8%). The median age at diagnosis was 70 years (range 52-84), and the median follow-up time was 55 months. The 5-year disease-free survival and the 5-year overall survival were 50.4% and 52.4%, respectively. Advanced disease stage was identified as an independent predictor of inferior disease-free (<0.003) and overall survival (p < 0.001). Except for stage, none of the traditional prognostic factors was associated with disease recurrence or death from disease. MEECs represent rare high-risk endometrial carcinomas with significant diagnostic and treatment challenges. Undoubtedly, the implementation of a molecular analysis can offer further diagnostic and management insights.

Immunohistochemical characterization of clear cell variant of hepatocellular carcinoma in a sheep

The cadaver and viscera of a mature female sheep (Ovis aries) underwent routine abattoir meat inspection. The liver was expanded by an infiltrative neoplastic mass comprising multifocal to coalescing, well-demarcated, pink to white-yellow nodules, up to 25 mm in diameter. An unencapsulated, moderately densely cellular, infiltrative neoplasm was present within the hepatic parenchyma. The neoplastic cells were arranged in solid sheets and acini supported by a moderately fine collagenous vascularized stroma. The neoplastic cells were moderately sized and polygonal, with clearly delineated cell borders and a moderate amount of cytoplasm that was clear or exhibited either globular eosinophilic deposits or fine fibrillar eosinophilic strands. The neoplastic cell nuclei were round and centrally located. The chromatin was lightly stippled and there was frequently a single, prominent, basophilic nucleolus. There were eight mitoses in 10 high-power fields (2.37 mm²). Most of the neoplastic cells had intense cytoplasmic immunolabelling for arginase 1, with frequent concurrent nuclear positivity, and mild to moderately intense punctate cytoplasmic labelling for hepatocyte specific antigen (Hep Par-1). The neoplastic cells did not label with anti-cytokeratin 19 antibody. Based on the histological appearance and the immunolabelling pattern, the neoplasm was diagnosed as the clear cell variant of a hepatocellular carcinoma.

Current Knowledge and Prospects for Renal Hemangioblastoma and Renal Cell Carcinoma with Hemangioblastoma-like Features

Tumors exhibiting histopathological findings similar to those of hemangioblastoma of the central nervous system (CNS-HB) rarely develop in the kidneys. Currently, renal hemangioblastoma (RHB) is considered analogous to CNS-HB; however, they differ in gross appearance, as well as immunohistochemical and molecular findings. In contrast, some renal cell carcinomas reportedly comprise distinct, clear cell renal cell carcinoma (CCRCC)- and hemangioblastoma (HB)-like areas. Initially, renal cell carcinomas with HB-like features (RCC-HBs) were considered a morphological variant of CCRCC owing to their diverse histological findings. However, the immunohistochemical and molecular findings of RCC-HBs suggest that RCC-HB is distinct from CCRCC. Additionally, one of the RCC-HBs had a focal leiomyomatous stroma and TSC2 variant, suggesting that RCC-HB and RCC with fibromyomatous stroma (RCC-FMS) might belong to the same disease entity. Therefore, we comprehensively reviewed the clinical, pathological, and molecular features of RHB, RCC-HB, and the related tumors and discussed the similarities, differences, and relationships between them. We believe that our review would serve as a foundation for further investigation on elucidating the relationship between CNS-HB, RHB, RCC-HB, and RCC-FMS.

Inferior Vena Cava (IVC) Resections without Reconstruction in Renal Tumors: Two Case Reports

(1) Background: We aim to present our experience with resection of the inferior vena cava (IVC) without reconstruction in two patients diagnosed with renal tumors. (2) Case Report: The first case was diagnosed with right renal vein sarcoma and the second case was diagnosed with clear cell renal carcinoma; both presented signs of invasion and thrombosis of the IVC at infrarenal and cruoric levels, along with the development of collateral circulation with the help of the paravertebral plexus. In both patients, en bloc right nephrectomy was performed along with the resection of the thrombosed IVC without further reconstruction. In the case of the patient with right vein sarcoma, preservation of the left renal and caval intrahepatic vein was possible, whilst in the second case diagnosed with clear cell renal carcinoma, the associated left renal thrombosis also enforced the resection of the left renal vein. (3) Discussion: Postoperative evolution was favorable in both cases and did not exhibit major complications. Antibiotic therapy, analgesics, and anticoagulant medication were administered at therapeutic doses after surgery in both cases. The histopathological examination of the surgical specimen confirmed the diagnoses of renal vein sarcoma in the first case and clear cell renal carcinoma in the second case. Surgical treatment and adjuvant chemotherapy prolonged survival for two years for the first case and for two months, up until this moment, for the second case. The survival of clear cell renal carcinoma is currently at two months. (4) Conclusions: The resection of the inferior vena cava, without subsequent reconstruction in cases presenting diffused distal thrombosis, can represent an alternative to IVC reconstruction, which might lead to a major ulterior risk of thrombosis. In some cases, this can result in long-term survival.

Clear cell mesotheliomas with inactivating VHL mutations and near-haploid genomic features

Clear cell mesothelioma is uncommon and shows predominance of clear cells with resemblance to clear cell carcinomas. Clinicopathologic and molecular descriptions of clear cell mesothelioma remained limited. In this study, we identified an index patient with clear cell mesothelioma, confirmed by immunohistochemical and ultrastructural studies. Targeted next-generation sequencing revealed the presence of an inactivating VHL mutation. We then systematically searched for VHL-mutant mesotheliomas in a comprehensive genomic profiling database of 1532 mesotheliomas. Collectively, we identified a cohort of four VHL-mutant clear cell mesotheliomas, including three peritoneal and one pleural tumors from three females and one male, with age range of 47-68 (median 63) years. Histologically, each tumor showed a microcystic to tubulopapillary architecture with prominent clear cells. By next-generation DNA sequencing, each of the four clear cell mesotheliomas harbored inactivating VHL mutations, while lacking other alterations typical of mesotheliomas such as BAP1, NF2, SETD2, CDKN2A, CDKN2B, TP53, and PTEN. By using low-pass whole genome sequencing on the index case and targeted next-generation sequencing on the remaining three cases, we identified extensive loss of heterozygosity throughout the genome but consistently sparing chromosomes 5, 7, and 20, characteristic of genomic near-haploidization. In summary, clear cell mesotheliomas were characterized by inactivating VHL mutations and genomic near-haploidization and appeared to represent a distinct clinicopathologic and molecular category of mesotheliomas. Our findings implicate VHL in the pathogenesis of a subset of mesotheliomas, particularly those with clear cell morphology.

p53 and ovarian carcinoma survival: an Ovarian Tumor Tissue Analysis consortium study

Our objective was to test whether p53 expression status is associated with survival for women diagnosed with the most common ovarian carcinoma histotypes (high-grade serous carcinoma [HGSC], endometrioid carcinoma [EC], and clear cell carcinoma [CCC]) using a large multi-institutional cohort from the Ovarian Tumor Tissue Analysis (OTTA) consortium. p53 expression was assessed on 6,678 cases represented on tissue microarrays from 25 participating OTTA study sites using a previously validated immunohistochemical (IHC) assay as a surrogate for the presence and functional effect of TP53 mutations. Three abnormal expression patterns (overexpression, complete absence, and cytoplasmic) and the normal (wild type) pattern were recorded. Survival analyses were performed by histotype. The frequency of abnormal p53 expression was 93.4% (4,630/4,957) in HGSC compared to 11.9% (116/973) in EC and 11.5% (86/748) in CCC. In HGSC, there were no differences in overall survival across the abnormal p53 expression patterns. However, in EC and CCC, abnormal p53 expression was associated with an increased risk of death for women diagnosed with EC in multivariate analysis compared to normal p53 as the reference (hazard ratio [HR] = 2.18, 95% confidence interval [CI] 1.36-3.47, p = 0.0011) and with CCC (HR = 1.57, 95% CI 1.11-2.22, p = 0.012). Abnormal p53 was also associated with shorter overall survival in The International Federation of Gynecology and Obstetrics stage I/II EC and CCC. Our study provides further evidence that functional groups of TP53 mutations assessed by abnormal surrogate p53 IHC patterns are not associated with survival in HGSC. In contrast, we validate that abnormal p53 IHC is a strong independent prognostic marker for EC and demonstrate for the first time an independent prognostic association of abnormal p53 IHC with overall survival in patients with CCC.

Renal cell carcinoma of different pathological types in bilateral native kidneys of a kidney transplant recipient: A case report and literature review

Patients after kidney transplantation have a much higher risk of developing malignant tumors than the general population. And the native kidney is an organ relatively susceptible to malignant tumors after renal transplantation. However, the simultaneous development of bilateral renal tumors is very rare; especially the bilateral native kidneys harbor different pathological types of renal cell carcinoma (RCC). We report a case of a patient who developed malignant tumors in both native kidneys nearly 19 years after renal transplantation. This patient underwent bilateral laparoscopic radical nephrectomy, and postoperative pathological examination showed clear cell RCC on the left native kidney and papillary RCC on the right one. And the early detection and surgical treatment resulted in a good prognosis. The literature related to the diagnosis and treatment of bilateral RCC after renal transplantation is also reviewed.

Primary Cutaneous Malignant Perivascular Epithelioïd Cell Tumor (PEComa): Case Report With Review of the Literature

Perivascular epithelioïd cell tumor (PEComa) is a mesenchymal neoplasm with epithelioïd or spindled morphology with numerous thin-walled capillaries between tumor cells. They co-express markers of both melanocytic and smooth muscle differentiation. PEComas are rare, presenting in numerous anatomic sites including lung, kidney, liver, genitourinary tract, soft tissue, and skin. Primary cutaneous PEComas are very rare entity, and malignant ones are even more uncommon. Herein, we report the case of a 92-year-old female which was presenting with 7 cm exophytic, ulcerated, hemorrhagic nodular tumor, and rapidly growing for 8 months over the right thigh. On histologic examination, we found a dermal neoplasm formed by an atypical clear cell tumor with numerous branching capillaries between tumor cells. The mitotic count was found 6 mitotic figures/10 HPF. On immunohistochemistry, tumor cells co-expressed smooth muscle and melanocytic markers, CD10, and CD68. Based on these findings, the diagnosis of primary cutaneous malignant perivascular epithelioïd cell tumor (PEComa) was made. The large size (7 cm), the count of mitoses (6 mitotic figures/10 HPF), and the nuclear pleomorphism argued for malignancy. The absence of soft tissue or visceral localization argued for the cutaneous primitive origin. Adjuvant radiotherapy and targeted therapy with mTOR inhibitor (nab-sirolimus) was indicated. To the best of our knowledge, this is only the eighth case of a primary cutaneous malignant PEComa reported in the literature to date.

Ciliated Cells in Ovarian Cancer Decrease with Increasing Tumor Grade and Disease Progression

Ciliated cell markers expressed in epithelial ovarian cancers (EOC) are associated with improved survival. We examined the distribution of cells expressing ciliated cell markers in various EOC histologies and stages. Immunohistochemistry and/or multiplex immunofluorescence were used to determine the expression of FOXJ1 and/or CAPS (ciliated cell markers) in tissue microarrays including 4 normal fallopian tubes, 6 normal endometria, 16 cystadenomas, 25 borderline tumors, 21 low-grade carcinomas, and 118 high-grade carcinomas (HGSOC) (46 serous, 29 endometrioid, 30 clear cell, 13 mucinous). CAPS+ cells were observed in normal fallopian tubes and endometria and in ~85% of serous benign and borderline tumors and low-grade carcinomas but only in <40% of HGSOC. mRNA data from an independent cohort showed higher FOXJ1 and CAPS expression in serous borderline tumors and low-grade carcinomas compared to HGSOC. In HGSOC, ciliated cell-positive markers were observed in 52% primary tumors compared to 26% of patient-matched synchronous metastases, and 24% metachronous metastases (p = 0.009). mRNA data from an independent HGSOC cohort showed lower levels of CAPS in metastases than in primary tumors (p = 0.03). Overall, the study revealed that ciliated cells were less common in mucinous EOC, the percentage of ciliated cell marker-positive cases decreased with increasing grade, and the percentage of ciliated cells decreased in HGSOC metastases compared to patient-matched primary tumors.

Aldosterone-Producing Adenomas of Increased Size Are Associated With Higher Steroidogenic Activity

CONTEXT

There are inconsistent results and insufficient evidence as to whether an association exists between the size and aldosterone-producing ability of aldosterone-producing adenomas.

OBJECTIVE

We further investigated this possible association retrospectively.

METHODS

A total of 142 cases of primary aldosteronism diagnosed as unilateral by adrenal venous sampling at 2 referral centers between 2009 and 2019 were included. We classified these individuals into small and large tumor groups using a diameter of 14 mm as a cutoff. This size was the median diameter of the tumor on the affected side of the adrenal gland. We compared plasma aldosterone concentration (PAC), plasma renin activity (PRA), PAC to PRA ratio, PAC from a saline infusion test (SIT), urinary aldosterone secretion (uAld), and serum potassium as indices of aldosterone-producing ability between the 2 groups. In some cases, we conducted histopathological evaluations and detection of the KCNJ5 mutation.

RESULTS

PAC, PAC to PRA ratio, PAC from SIT, and uAld were higher and serum potassium was lower in the large tumor group. PAC, PAC from SIT, uAld, and serum potassium significantly correlated with tumor diameter. PRA was not associated with tumor diameter. Clear cell-dominant cases were more common in the large tumor group, while cases showing a strong expression of CYP11B2 were not significantly different between the groups. KCNJ5 mutations tended to be more common in the large tumor group.

CONCLUSION

The higher aldosterone-producing ability in larger adenomas can be used to infer the responsible lesion and disease type.

Optimal Choice of Adjuvant Treatment for Renal Cell Carcinoma Following Nephrectomy

Renal cell carcinoma (RCC) is the fourteenth most common cancer worldwide. In about 55% of cases, it is diagnosed at a localised and/or locally advanced stage and therefore amenable to a curative approach. Although nephrectomy still represents the cornerstone of non-metastatic RCC (nmRCC) treatment, a relapse is observed in about 25–30% of patients undergoing curative surgery. Prognosis is drastically influenced by lymph nodal involvement. After the first disappointing results with a cytokine-based strategy, tyrosine kinase inhibitors (TKIs) were tested as adjuvant agents. Despite their efficacy in the metastatic setting, results in terms of disease-free survival (DFS) are not unequivocal and the overall survival (OS) benefit has not been demonstrated. Moreover, their toxicity profile induced a remarkable percentage of patients to discontinue the treatment. On the contrary, the KEYNOTE-564 trial showed the benefit of adjuvant pembrolizumab compared with placebo in terms of DFS with promising results in term of OS. Patients included were at intermediate or high risk of relapse, or patients with no evidence of disease after metastasectomy (M1 NED). The updated analysis presented at the American Society of Clinical Oncology Genito-Urinary (ASCO GU) 2022 confirmed the benefit of pembrolizumab versus placebo over time, although OS data are still immature. A longer follow-up and the several ongoing trials with immune checkpoint inhibitors (ICIs) will provide further data about adjuvant immuno-oncology (IO). Furthermore, the patients’ selection based on clinical or biological features will be crucial in order to identify who benefits most from treatments.

Metastatic Clear Cell Renal Cell Carcinoma Involving the Thyroid Gland: A Clinicopathologic Study of 17 Patients

Background. Metastatic clear cell renal cell carcinoma (RCC) is one of the most common secondary thyroid malignancies. Diagnosis can be challenging, particularly if presenting many years after initial diagnosis. We reviewed clinicopathologic features and immunoprofile of metastatic clear cell RCC in thyroid. Design. We identified 17 patients from 2003-2021. Clinical data were obtained from medical records, and slides were retrieved and reviewed. Results. Seventeen patients (12 male and 5 female) included 12 thyroidectomies, 3 core biopsies, 1 excisional biopsy, and 1 fine-needle aspiration. The average patient age was 68.7 years (range, 45-88 years). Sixteen patients had history of clear cell RCC, and in 1 patient, the clear cell RCC was discovered after the thyroid metastasis was found. Thyroid gland metastases were on average diagnosed 90.7 months after the diagnosis of the renal primary (range, 24-240 months). Patients presented with a new palpable mass (n = 11) or dyspnea/stridor (n = 1). Five tumors were incidentally found via surveillance imaging. In 2 patients, metastases occurred within follicular thyroid neoplasms. All metastases showed conspicuous sinusoidal vasculature between the tumor nests and areas of myxoid degeneration. A prominent thick fibromuscular pseudocapsule was evident in 10 resections. Immunohistochemistry (n = 5) showed that the metastases were positive for PAX8, CA9, and CD10, while negative for keratin 7, thyroglobulin, and TTF1. Conclusions. Metastatic clear cell RCC involving the thyroid gland is infrequent and typically occurs remotely after the initial diagnosis. Cytologic and histologic features may show significant overlap with primary thyroid lesions. Immunohistochemistry can help reliably distinguish metastases from primary thyroid neoplasms.

Telaglenastat plus Everolimus in Advanced Renal Cell Carcinoma: A Randomized, Double-Blinded, Placebo-Controlled, Phase II ENTRATA Trial

PURPOSE

Glutaminase is a key enzyme, which supports elevated dependency of tumors on glutamine-dependent biosynthesis of metabolic intermediates. Dual targeting of glucose and glutamine metabolism by the mTOR inhibitor everolimus plus the oral glutaminase inhibitor telaglenastat showed preclinical synergistic anticancer effects, which translated to encouraging safety and efficacy findings in a phase I trial of 2L+ renal cell carcinoma (RCC). This study evaluated telaglenastat plus everolimus (TelaE) versus placebo plus everolimus (PboE) in patients with advanced/metastatic RCC (mRCC) in the 3L+ setting (NCT03163667).

PATIENTS AND METHODS

Eligible patients with mRCC, previously treated with at least two prior lines of therapy [including ≥1 VEGFR-targeted tyrosine kinase inhibitor (TKI)] were randomized 2:1 to receive E, plus Tela or Pbo, until disease progression or unacceptable toxicity. Primary endpoint was investigator-assessed progression-free survival (PFS; one-sided α <0.2).

RESULTS

Sixty-nine patients were randomized (46 TelaE, 23 PboE). Patients had a median three prior lines of therapy, including TKIs (100%) and checkpoint inhibitors (88%). At median follow-up of 7.5 months, median PFS was 3.8 months for TelaE versus 1.9 months for PboE [HR, 0.64; 95% confidence interval (CI), 0.34-1.20; one-sided P = 0.079]. One TelaE patient had a partial response and 26 had stable disease (SD). Eleven patients on PboE had SD. Treatment-emergent adverse events included fatigue, anemia, cough, dyspnea, elevated serum creatinine, and diarrhea; grade 3 to 4 events occurred in 74% TelaE patients versus 61% PboE.

CONCLUSIONS

TelaE was well tolerated and improved PFS versus PboE in patients with mRCC previously treated with TKIs and checkpoint inhibitors.

Recurrent WWTR1 S89W mutations and Hippo pathway deregulation in clear cell carcinomas of the cervix

Clear cell carcinoma (CCC) of the cervix (cCCC) is a rare and aggressive type of human papillomavirus (HPV)-negative cervical cancer with limited effective treatment options for recurrent or metastatic disease. Historically, CCCs of the lower genital tract were associated with in utero diethylstilbestrol exposure; however, the genetic landscape of sporadic cCCCs remains unknown. Here we sought to define the molecular underpinning of cCCCs. Using a combination of whole-exome, targeted capture, and RNA-sequencing, we identified pathogenic genetic alterations in the Hippo signaling pathway in 50% (10/20) of cCCCs, including recurrent WWTR1 S89W somatic mutations in 40% (4/10) of the cases harboring mutations in the Hippo pathway. Irrespective of the presence or absence of Hippo pathway genetic alterations, however, all primary cCCCs analyzed in this study (n = 20) harbored features of Hippo pathway deregulation at the transcriptomic and protein levels. In vitro functional analysis revealed that expression of the WWTR1 S89W mutation leads to reduced binding of TAZ to 14-3-3, promoting constitutive nuclear translocation of TAZ and Hippo pathway repression. WWTR1 S89W expression was found to lead to acquisition of oncogenic behavior, including increased proliferation, migration, and colony formation in vitro as well as increased tumorigenesis in vivo, which could be reversed by targeted inhibition of the TAZ/YAP1 complex with verteporfin. Finally, xenografts expressing WWTR1 S89W displayed a shift in tumor phenotype, becoming more infiltrative as well as less differentiated, and were found to be composed of cells with conspicuous cytoplasmic clearing as compared to controls. Our results demonstrate that Hippo pathway alterations are likely drivers of cCCCs and likely contribute to the clear cell phenotype. Therapies targeting this pathway may constitute a new class of treatment for these rare, aggressive tumors. © 2022 The Pathological Society of Great Britain and Ireland.

Clear cell variant of chondrosarcoma of calcaneum: A case report with review of the literature

Clear cell chondrosarcoma (CCC) is an uncommon variant constituting less than 2% of all chondrosarcomas. CCC arises most commonly in the proximal end of the femur, followed by the humerus, and other small bones. CCC involving the tarsal bone is very rare, and to the best of our knowledge, only one case has been described involving the calcaneum in the English literature to date. In this article, we discuss a case of CCC involving the right calcaneum with complete clinico-immuno-histomorphological features, which is successfully managed by below-knee amputation. We also reviewed the reported cases of chondrosarcomas involving the calcaneum with special reference to clinical features, therapy, morphology, and follow-up data.

Histological Tracking into the Third Dimension: Evolution of Early Tumorigenesis in VHL Kidney

Using a novel three-dimensional (3D) approach, we tracked histological changes to elucidate the earliest stages of renal clear cell neoplasia in normal kidney tissue of patients with von Hippel-Lindau (VHL) disease. Tissue blocks of interest were procured, serially sectioned, and 3D reconstruction of the entirety of pathologic events was performed. The results reveal an abundance of foci with aberrant clear cell proliferation that initially develop along the tubular lining, but have the potential to aggregate within individual tubules. This stage is followed by the extension of clear cell aggregates beyond the tubular basement membrane, which allows for the recruitment of angiogenesis derived from interstitial vasculature. The results suggest that the most frequent pathologic event in VHL kidneys is the presence of isolated or aggregated clear cells within the tubular epithelium, potentially developing further into a protracted process of neoplasia. The abundance of independent pathologic events in VHL kidneys confirms developmental mechanisms to precede tumor initiation. To our knowledge, this is the first report demonstrating that tracking of histologic changes in the 3rd dimension enables the confirmation of the sequence of events from the earliest pathologic change in the VHL kidney to the neoplastic stage. This approach is not only useful for visualization and quantification of pathologic changes but also for targeted sampling allowing selective analysis of the earliest stages of clear cell carcinogenesis.

Conditional survival of metastatic clear cell renal cell carcinoma: How prognosis evolves after cytoreductive surgery of primary tumor

Introduction

Cytoreductive surgery is one of the recommended treatments for metastatic renal cell carcinoma, while the prognostic information of these patients treated with cytoreductive surgery is limited. In this study, we aimed to investigate the survival profiles based on conditional survival (CS) estimates in metastatic clear cell renal cell carcinoma (mccRCC) patients treated with cytoreductive surgery of primary tumor.

Methods and materials

We identified and extracted mccRCC patients from the Surveillance, Epidemiology, and End Results database. We used Kaplan–Meier method to perform CS analyses. A multivariate Cox regression model was applied to explore the changes of well‐known prognostic factors.

Results

Conditional overall survival (COS) and conditional cancer‐specific survival (CCSS) improved increasingly at all periods of survivorships compared to survival estimates at baseline in overall population of mccRCC. The 36‐month COS improved by 3.3%–6.4% given per 12 additional months of survivorships and the CCSS improved significantly from 45.1% (95% CI 42.8–47.3) at 12 months to 67.1% (95% CI 62.0–71.7) at 60 months. Much more survival gain was observed in patients with advanced disease. Furthermore, the prognostic significance of age and pathological factors diminished and even disappeared in a long‐term survivorship.

Conclusions

Conditional overall survival and CCSS improved with time dynamically in mccRCC patients treated with cytoreductive surgery of primary tumor. Patients with advanced disease achieved significant survival gain and even could harvest a better prognosis given that the time of survivorship exceeds a certain period. Our findings could provide valuable and practical data for patient counseling and surveillance strategy making.

Lipidomic Analysis of Archival Pathology Specimens Identifies Altered Lipid Signatures in Ovarian Clear Cell Carcinoma

Cancer metabolism is associated with the enhanced lipogenesis required for rapid growth and proliferation. However, the magnitude of dysregulation of diverse lipid species still requires significant characterization, particularly in ovarian clear cell carcinoma (OCCC). Here, we have implemented a robust sample preparation workflow together with targeted LC-MS/MS to identify the lipidomic changes in formalin-fixed paraffin-embedded specimens from OCCC compared to tumor-free ovarian tissue. We quantitated 340 lipid species, representing 28 lipid classes. We observed differential regulation of diverse lipid species belonging to several glycerophospholipid classes and trihexosylceramide. A number of unsaturated lipid species were increased in OCCC, whereas saturated lipid species showed a decrease in OCCC compared to the controls. We also carried out total fatty acid analysis and observed an increase in the levels of several unsaturated fatty acids with a concomitant increase in the index of stearoyl-CoA desaturase (SCD) in OCCC. We confirmed the upregulation of SCD (the rate-limiting enzyme for the synthesis of monounsaturated fatty acids) by immunohistochemistry (IHC) assays. Hence, by carrying out a mass spectrometry analysis of archival tissue samples, we were able to provide insights into lipidomic alterations in OCCC.

SERPINB11 Expression Is Associated With Prognosis of High-grade Serous and Clear Cell Carcinoma of the Ovary

BACKGROUND/AIM

To evaluate the role of serine protease inhibitor B11 (SERPINB11) expression as a prognostic biomarker in high-grade serous carcinoma (HGSC) and clear cell carcinoma of the ovary (CCC).

MATERIALS AND METHODS

We obtained tumor tissues from patients with HGSC (n=145) and CCC (n=59). We evaluated immunohistochemically the expression of SERPINB11 and investigated whether SERPINB11 expression affects platinum-resistance and the prognosis of HGSC and CCC.

RESULTS

High expression of SERPINB11 was more common in CCC than in HGSC (57.6% vs. 28.3%; p<0.01), and SEPRINB11 expression did not correlate with platinum-resistance of HGSC and CCC. High expression of SERPINB11 was associated with worse progression-free survival and overall survival with marginal significance in HGSC; no relation between SERPINB11 expression and the prognosis of CCC was found.

CONCLUSION

SERPINB11 expression maybe a prognostic biomarker for HGSC.

A Rare Case of Trichilemmal Carcinoma: Histology and Management

Trichilemmal carcinoma (TC) is a rare cutaneous tumor thought to be derived from the follicular outer root sheath (ORS). It often manifests as a nondescript skin-colored or pink papule on the hair-bearing, sun-exposed anatomic sites of elderly patients. Trichilemmal carcinoma shows many histologic features reminiscent of follicular ORS-notably, its glycogen-rich clear cells, trichilemmal keratinization, and similar immunostaining profile. Historically, it has been described as following a relatively indolent clinical course, but cases of recurrence, local aggression, and distant metastases have recently been elucidated. Here, we report the case of a 66-year-old male patient who presented with an asymptomatic, erythematous plaque on his neck; biopsy confirmed a diagnosis of TC. The patient deferred Mohs micrographic surgery in favor of wide local excision and was treated successfully with 3-mm margins. Salient histopathologic features, treatment modalities, and management recommendations are discussed.

Differential Diagnosis between Oral Metastasis of Renal Cell Carcinoma and Salivary Gland Cancer

Renal cell carcinoma, which has clear cells in 70% of cases, has a high frequency of hematogenous distant metastases to lung, bone, liver, and other areas. Metastatic cancer accounts for 1 to 3% of malignant tumors in the stomatognathic region, and the metastasis of renal cell carcinoma to the oral mucosal tissue, though extremely rare, does occur. In addition, clear cells have been observed in some salivary gland cancers in the oral cavity. Therefore, the differential diagnosis of metastatic renal cell carcinoma and salivary gland cancer is important. This review discusses the differential diagnosis between metastatic renal cell carcinoma and malignant tumors of the salivary gland.

Clear-cell renal cell carcinoma - A comprehensive review of agents used in the contemporary management of advanced/metastatic disease

Renal cell carcinoma represents the most common malignancy of the kidney and the majority of cases are categorized as clear cell carcinomas. The elucidation of the specific alterations in key molecular and metabolic pathways responsible for cancer development and progression have prompted the rationalization of our classification of this disease and have provided specific targetable molecules implicated in carcinogenesis. Although immunotherapy has been an established option in the treatment of metastatic renal cell cancer for many years, its role has been renewed and upgraded with the implementation of anti-angiogenic agents and immune checkpoint inhibitors in our treatment armamentarium. The future holds promise, as newer agents become available and combination regimens of immunotherapy with anti-angiogenic agents have become the standard of care in the management of metastatic disease and are currently being evaluated in earlier settings. Proper patient selection and individualization of our treatment strategies are of utmost importance in order to provide optimal care to patients suffering from renal cell carcinoma.

Prognostic role of macrophage migration inhibitory factor in patients with clear cell renal cell carcinoma

Macrophage migration inhibitory factor (MIF) is a cytokine that mediates the interaction between malignant cells and the innate immune system. Recently, MIF has received attention for its role in tumorigenesis. We evaluated the prognostic role of MIF in clear cell renal cell carcinoma (CCRCC).A total of 152 patients, who underwent nephrectomy for CCRCC were enrolled in this study. Immunohistochemical staining of tissue microarray blocks containing 298 cores-2 cores per CCRCC patient was performed. The relationship between MIF expression and clinicopathological factors was evaluated. Total RNA and protein were extracted from 7 RCC (renal cell carcinoma) cell lines. MIF was knocked down in Caki-2 cells, and a wound healing assay was performed to evaluate migratory activity.Among the 298 cores, 180 (60.4%) were positive for MIF. Multivariate analysis, showed that, CCRCC patients with negative MIF expression exhibited poor disease-free survival (hazard ratio: 2.087, 95% confidence interval: 0.821-5.307, P value: .023) and poor disease-specific survival (hazard ratio: 2.101, 95% confidence interval: 1.009-4.374, P value: .047). The wound healing assay revealed that cell confluence was lower in MIF-deficient Caki-2 cells than in control cells.Negative MIF expression might be an independent prognostic marker for patients with CCRCC.

Oncogenic potential of macrophage‑capping protein in clear cell renal cell carcinoma

Macrophage-capping protein (CapG) is a newly characterized oncogene involved in several types of cancer. However, the expression patterns and biological mechanisms of CapG in clear cell renal cell carcinoma (ccRCC) are unclear. The present study aimed to investigate the roles of CapG in the prognosis, proliferation and metastasis of ccRCC. In the present study, the expression of CapG was analyzed by western blotting in 24 paired ccRCC and adjacent normal tissue samples. Another 152 tissue samples from 152 patients with ccRCC were examined by immunohistochemistry. Compared with normal tissue, CapG expression was significantly increased in ccRCC tissue, and high CapG expression was associated with advanced tumor stage, histological grade, lymph node metastasis, and poor overall survival. Moreover, CapG was an independent predictor of survival. Lentivirus-mediated CapG knockdown significantly inhibited 786-O cell proliferation, migration, and invasion, induced cell cycle arrest at the G₂/M phase, and increased apoptosis in vitro. Microarray analysis indicated that RAC, CDC42 and ERK/MAPK signaling were disrupted by CapG knockdown in 786-O cells. In conclusion, the present findings indicate that CapG plays an oncogenic role in ccRCC and may represent a potential therapeutic target for this disease.

Biomarker Development for Metastatic Renal Cell Carcinoma: Omics, Antigens, T-cells, and Beyond

The treatment of metastatic renal cell carcinoma has evolved quickly over the last few years from a disease managed primarily with sequential oral tyrosine kinase inhibitors (TKIs) targeting the vascular endothelial growth factor (VEGF) pathway, to now with a combination of therapies incorporating immune checkpoint blockade (ICB). Patient outcomes have improved with these innovations, however, controversy persists regarding optimal sequence and patient selection amongst the available combinations. Ideally, predictive biomarkers would aid in guiding treatment decisions and personalizing care. However, clinically-actionable biomarkers have remained elusive. We aim to review the available evidence regarding biomarkers for both TKIs and ICB and will present where the field may be headed in the years to come.

Characterization of Mutational Status, Spheroid Formation, and Drug Response of a New Genomically-Stable Human Ovarian Clear Cell Carcinoma Cell Line, 105C

Ovarian clear cell carcinoma (OCCC) is a rare subtype of gynecological cancer for which well-characterized and authenticated model systems are scarce. We provide an extensive characterization of ‘105C’, a cell line generated from an adenocarcinoma of the clear cell histotype using targeted next-generation sequencing, cytogenetic microarrays, along with analyses of AKT/mTOR signaling. We report that that the 105C cell line is a bona fide OCCC cell line, carrying PIK3CA, PTEN, and ARID1A gene mutations, consistent with OCCC, yet maintain a stable genome as reflected by low copy number variation. Unlike KOC-7c, TOV-21G, and RMG-V OCCC lines also mutated for the above genes, the 105C cells do not carry mutations in mismatch repair genes. Importantly, we show that 105C cells exhibit greater resistance to mTOR inhibition and carboplatin treatment compared to 9 other OCCC cell lines in 3D spheroid cultures. This resistance may be attributed to 105C cells remaining dormant in suspension culture which surprisingly, contrasts with several other OCCC lines which continue to proliferate in long-term suspension culture. 105C cells survive xenotransplantation but do not proliferate and metastasize. Collectively, we show that the 105C OCCC cell line exhibits unique properties useful for the pre-clinical investigation of OCCC pathobiology.

Adrenal Metastases as Sanctuary Sites in Advanced Renal Cancer

Involvement of the adrenal gland in kidney cancer represents a unique site of metastasis with a distinct clinical course. The cases are typically resistant to immune therapy and need local therapy management. A case series of patients with adrenal metastases was reviewed to highlight the nuances of clinical course and therapy. We reviewed renal cancer carcinoma (RCC) cases with adrenal metastases at Karmanos Cancer Center, Detroit MI. Medical records were reviewed to collect relevant case information. Next-generation sequencing, tumor mutation burden testing, and programmed death ligand biomarkers were evaluated in five cases. Twelve cases were reviewed; all were males with a median age of 49.5 years. Three patients presented with adrenal metastases only and were treated with local therapy. Three received interleukin-2 (IL-2). One patient relapsed with bilateral adrenal lesions after 11 years of remission, post-IL-2 therapy. Five cases received immune checkpoint inhibitor (ICI) and one received antivascular therapy. ICI therapy was followed by ablation of residual adrenal metastases in three patients. Genomic profiling was available in five cases. All were BAP1 and PD-L1 negative.Pathogenic mutations in PBRM1, SETD2, and VHL were noted. All patients with residual adrenal metastases responded to antivascular therapies or to local ablation. One patient died 17 years after diagnosis and 11 patients are alive at a median follow-up of 9.5 years. Adrenal metastases in RCC have a distinct clinical course. They can represent a sanctuary site of relapse/residual disease following treatment with immune therapy. Management with local therapy can induce durable remissions. Systemic management with antivascular therapies also demonstrated favorable responses. Further investigation should focus on the unique clinical course and optimal management of adrenal metastases in kidney cancer.

Carbonic Anhydrase IX in Renal Cell Carcinoma, Implications for Disease Management

Carbonic Anhydrase IX (CAIX) is a well-described enzyme in renal cell carcinoma, with its expression being regulated by the hypoxia-inducible factor 1 alpha, it is known for interfering with hypoxia processes. Renal carcinoma encompasses a broad spectrum of histological entities and is also described as a heterogeneous malignant tumor. Recently, various combinations of checkpoint inhibitors and targeted therapies have been validated to manage this disease. Reliable markers to confirm the diagnosis, estimate the prognosis, predict or monitor the treatment response are required. Molecular imaging developments allow a comprehensive analysis of the tumor, overcoming the spatial heterogeneity issue. CAIX, being highly expressed at the tumor cell surfaces of clear cell renal carcinoma, also represents a potential treatment target. In this manuscript we reviewed the current knowledge from the literature on the pathophysiological interactions between renal cell carcinoma and CAIX, the role of CAIX as a marker for diagnosis, prognosis, treatment monitoring and molecular imaging, and the potential target for therapeutic strategies.

Features of increased malignancy in eosinophilic clear cell renal cell carcinoma

Clear cell renal cell carcinoma (ccRCC) is the most common form of renal cancer. Due to inactivation of the von Hippel-Lindau tumour suppressor, the hypoxia-inducible transcription factors (HIFs) are constitutively activated in these tumours, resulting in a pseudo-hypoxic phenotype. The HIFs induce the expression of genes involved in angiogenesis and cell survival, but they also reset the cellular metabolism to protect cells from oxygen and nutrient deprivation. ccRCC tumours are highly vascularized and the cytoplasm of the cancer cells is filled with lipid droplets and glycogen, resulting in the histologically distinctive pale (clear) cytoplasm. Intratumoural heterogeneity may occur, and in some tumours, areas with granular, eosinophilic cytoplasm are found. Little is known regarding these traits and how they relate to the coexistent clear cell component, yet eosinophilic ccRCC is associated with higher grade and clinically more aggressive tumours. In this study, we have for the first time performed RNA sequencing comparing histologically verified clear cell and eosinophilic areas from ccRCC tissue, aiming to analyse the characteristics of these cell types. Findings from RNA sequencing were confirmed by immunohistochemical staining of biphasic ccRCC. We found that the eosinophilic phenotype displayed a higher proliferative drive and lower differentiation, and we confirmed a correlation to tumours of higher stage. We further identified mutations of the tumour suppressor p53 (TP53) exclusively in the eosinophilic ccRCC component, where mTORC1 activity was also elevated. Also, eosinophilic areas were less vascularized, yet harboured more abundant infiltrating immune cells. The cytoplasm of clear cell ccRCC cells was filled with lipids but had very low mitochondrial content, while the reverse was found in eosinophilic tissue. We herein suggest possible transcriptional mechanisms behind these phenomena. © 2020 The Authors. The Journal of Pathology published by John Wiley & Sons, Ltd. on behalf of The Pathological Society of Great Britain and Ireland.

Trends in Initial Systemic Therapy for Elderly Patients with Metastatic Clear Cell Renal Cell Carcinoma

BACKGROUND

The treatment landscape for metastatic clear cell renal cell carcinoma (mRCC) is rapidly changing. It is unknown how adoption of new types of therapies may differ by patient age.

OBJECTIVE

To compare trends in first-line therapy use for older (≥70 years) and younger (< 70) patients with mRCC before and after approval of nivolumab in 2015.

METHODS

Using the National Cancer Database, we assessed trends in first-line therapy use by calculating the proportion of patients receiving targeted therapy, immunotherapy, or no systemic therapy by year of diagnosis. Initial systemic treatment was compared for patients diagnosed in 2016 with patients diagnosed in 2011 as a control group prior to nivolumab approval. Multivariable regression analysis was used to evaluate the interaction between year of diagnosis and elderly status for use of first-line immunotherapy or targeted therapy.

RESULTS

From 2006 to 2016, the proportion of patients receiving any type of systemic therapy increased from 43.7% to 56.5%. On stratified multivariable regression analysis, older patients diagnosed in 2016 were 17.3 times more likely to receive first-line immunotherapy compared to those diagnosed in 2011, while younger patients were 2.3 times more likely. There was no change in targeted therapy use over this time regardless of patient age.

CONCLUSIONS

The rate of adoption of first-line immunotherapy was particularly pronounced for elderly compared to younger patients. While first-line use of immunotherapy may have allowed elderly patients to receive systemic therapy that they otherwise would not, the efficacy of these drugs in elderly patients deserves further study.

Rare Case of Renal-type Clear Cell Carcinoma of the Prostate and Review of the Literature

BACKGROUND/AIM

Renal-type clear cell carcinoma (RTCCC) occurring as a primary tumor in an extra-renal location, especially in the prostate, is very rare. In this report, we present a rare case of RTCCC of the prostate and review the current literature on this condition.

CASE REPORT

The patient was a 76-year-old man who presented with urinary symptoms. Cystoscopic findings showed tumor-like lesions in the dome, neck, and anterior wall of the urinary bladder. Biopsy revealed clear cell carcinoma (CCC). Transrectal needle biopsy of the prostate revealed prostatic adenocarcinoma with CCC features. Immunohistochemically, tumor cells of the bladder and prostate were compatible with prostatic carcinoma. The whole-body radiologic workup did not reveal any renal or other organ malignancies. Transurethral resection of the prostate and bladder tumor was performed. The patient underwent regular follow-up cystoscopic examination and urine cytology. No recurrence was observed 19 months after the diagnosis.

CONCLUSION

This was a case of RTCCC arising in the prostate. RTCCC of the prostate is extremely rare and shows very similar histological and immunohistochemical features to those of CCC occurring in the kidney. Pathologists should be aware of such an entity whenever they see clear cells in urinary tract malignancies.

Rare Case of Renal-type Clear Cell Carcinoma of the Prostate and Review of the Literature

BACKGROUND/AIM

Renal-type clear cell carcinoma (RTCCC) occurring as a primary tumor in an extra-renal location, especially in the prostate, is very rare. In this report, we present a rare case of RTCCC of the prostate and review the current literature on this condition.

CASE REPORT

The patient was a 76-year-old man who presented with urinary symptoms. Cystoscopic findings showed tumor-like lesions in the dome, neck, and anterior wall of the urinary bladder. Biopsy revealed clear cell carcinoma (CCC). Transrectal needle biopsy of the prostate revealed prostatic adenocarcinoma with CCC features. Immunohistochemically, tumor cells of the bladder and prostate were compatible with prostatic carcinoma. The whole-body radiologic workup did not reveal any renal or other organ malignancies. Transurethral resection of the prostate and bladder tumor was performed. The patient underwent regular follow-up cystoscopic examination and urine cytology. No recurrence was observed 19 months after the diagnosis.

CONCLUSION

This was a case of RTCCC arising in the prostate. RTCCC of the prostate is extremely rare and shows very similar histological and immunohistochemical features to those of CCC occurring in the kidney. Pathologists should be aware of such an entity whenever they see clear cells in urinary tract malignancies.

Cystadenoma of the tongue: report of a case with long-term follow-up

Cystadenoma is a rare benign salivary gland neoplasm characterized by a predominantly multicystic growth pattern. The parotid gland is involved in about 45–50% of cystadenoma cases, with the minor glands of the lip and buccal mucosa being the next most common sites. The tongue is rarely involved; only one congenital case is reported in the literature. Here, we report a 63-year-old man who was referred to our hospital for a nodule on the right edge of his tongue that developed into an elastic soft mass, 4 mm in diameter. It was clinically diagnosed as a benign tumour and removed under local anaesthesia. Microscopically, the lesion was composed of multiple cysts of various sizes and shapes, with or without papillary intraluminal short projections. It was diagnosed as cystadenoma. The postoperative course was uneventful, and we found no evidence of recurrence at the postoperative 14-year follow-up.

Avelumab and axitinib combination therapy for the treatment of advanced renal cell carcinoma

Owing to an improved understanding of the immunobiological profile of renal cell carcinoma (RCC), the past few years have ushered in significant changes in systemic therapies for advanced stage RCC. First-line treatment with single-agent tyrosine kinase inhibitors (TKI) has been virtually replaced for most patients by immunotherapy combinations. The first of such treatments was the dual immune checkpoint inhibitor combination of ipilimumab and nivolumab. More recently, the combination of an immune checkpoint inhibitor and a TKI has also moved into the first-line setting. This review summarizes the pharmacologic properties, evidence for use and safety of avelumab, a PD-L1 inhibitor and axitinib a small-molecule TKI, each as monotherapy, and in combination for the management of metastatic RCC.

Primary Retroperitoneal Müllerian Adenocarcinoma: Report of Two Cases Treated With Radical Surgery

BACKGROUND

Primary retroperitoneal Müllerian adenocarcinoma (PRMA) is a very rare type of primary retroperitoneal tumour. CASE 1: A 45-year-old woman presented with left lower extremity swelling and pain. Imaging revealed that the tumour had invaded the left common iliac vein and artery, internal and external iliac arteries, sciatic and obturator nerves, and pelvic wall. CASE 2: A 37-year-old was admitted with pelvic pain. Imaging showed the tumor at the left iliac bifurcation infiltrating the internal iliac artery and left sciatic, obturator, and femoral nerves. Both of these patients were treated with radical surgery that achieved no visible tumour at the end of the operation.

CONCLUSION

There is no guideline for the diagnosis and management of this entity due to its rarity. These cases should be managed at highly specialized centres with expertise in radical surgery.

Systemic therapy for non-serous ovarian carcinoma

Ovarian cancer is one of the top ten most common cancers in women around the world, with high-grade serous epithelial cancer being the most frequent type. However, around a quarter of cases consist of non-serous epithelial ovarian cancer (EOC), which is a heterogeneous group of malignancies that includes endometroid, mucinous, clear cell carcinoma (CCC), and carcinosarcoma. Another relevant group of nonepithelial tumors are those arising from germ cells or sex-cord stromal cells, which account for about 10% of all ovarian cancers. Although there are similarities in the presentation, evaluation, and management of these tumors, they have unique characteristics in terms of epidemiology, tumor biology, tumor marker expression, and response to treatment, warranting a different approach to each one of them. Collectively, the treatment of most of EOC include surgical cytoreduction followed by adjuvant systemic platinum-based chemotherapy. The most common chemotherapy and route of administration for systemic treatment is paclitaxel plus carboplatin given intravenously. However, the treatment of EOC has been rapidly evolving and emerging targeted therapies such as poly (adenosine diphosphate-ribose) polymerase inhibitors, immune checkpoint inhibitors, and antiangiogenic agents are also available. On the other hand, non-EOC responds well to combination chemotherapy used to treat testicular cancer (bleomycin, etoposide, cisplatin) and has a good prognosis. Frontline chemotherapeutic regimen selection differs according to histological subtype, molecular alterations, and patient characteristics. Here, we review specific characteristics of non-serous and non-EOC emphasizing the peculiarities of systemic therapy for each subtype.

Prognostic Molecular Signatures for Metastatic Potential in Clinically Low-Risk Stage I and II Clear Cell Renal Cell Carcinomas

Introduction: For patients with localized node-negative (Stage I and II) clear cell renal cell carcinomas (ccRCC), current clinicopathological staging has limited predictive capability because of their low risk. Analyzing molecular signatures at the time of nephrectomy can aid in understanding future metastatic potential.

Objective: Develop a molecular signature that can stratify patients who have clinically low risk ccRCC, but have high risk genetic changes driving an aggressive metastatic phenotype.

Patients, Materials, and Methods: Presented is the differential expression of mRNA and miRNA in 44 Stage I and Stage II patients, 21 who developed metastasis within 5 years of nephrectomy, compared to 23 patients who remained disease free for more than 5 years. Extracted RNA from nephrectomy specimens preserved in FFPE blocks was sequenced using RNAseq. MiRNA expression was performed using the TaqMan OpenArray qPCR protocol.

Results: One hundred thirty one genes and 2 miRNA were differentially expressed between the two groups. Canonical correlation (CC) analysis was applied and four CCs (CC32, CC20, CC9, and CC7) have an AUC > 0.65 in our dataset with similar predictive power in the TCGA-KIRC dataset. Gene set enrichment showed CC9 as kidney development/adhesion, CC20 as oxidative phosphorylation pathway, CC32 as RNA binding/spindle and CC7 as immune response. In a multivariate Cox model, the four CCs were able to identify high/low risk groups for metastases in the TCGA-KIRC (p < 0.05) with odds ratios of CC32 = 5.7, CC20 = 4.4, CC9 = 3.6, and CC7 = 2.7.

Conclusion: These results identify molecular signatures for more aggressive tumors in clinically low risk ccRCC patients who have a higher potential of metastasis than would be expected.

Modeling the Diversity of Epithelial Ovarian Cancer through Ten Novel Well Characterized Cell Lines Covering Multiple Subtypes of the Disease

Cancer cell lines are amongst the most important pre-clinical models. In the context of epithelial ovarian cancer, a highly heterogeneous disease with diverse subtypes, it is paramount to study a wide panel of models in order to draw a representative picture of the disease. As this lethal gynaecological malignancy has seen little improvement in overall survival in the last decade, it is all the more pressing to support future research with robust and diverse study models. Here, we describe ten novel spontaneously immortalized patient-derived ovarian cancer cell lines, detailing their respective mutational profiles and gene/biomarker expression patterns, as well as their in vitro and in vivo growth characteristics. Eight of the cell lines were classified as high-grade serous, while two were determined to be of the rarer mucinous and clear cell subtypes, respectively. Each of the ten cell lines presents a panel of characteristics reflective of diverse clinically relevant phenomena, including chemotherapeutic resistance, metastatic potential, and subtype-associated mutations and gene/protein expression profiles. Importantly, four cell lines formed subcutaneous tumors in mice, a key characteristic for pre-clinical drug testing. Our work thus contributes significantly to the available models for the study of ovarian cancer, supplying additional tools to better understand this complex disease.

Clear cell carcinoma of breast lipid-rich variant

Clear cell breast carcinomas are one of the rare types of invasive carcinoma of the breast. Among them, lipid-rich variant is still rare comprising <1%. The tumor derives its name from the intracytoplasmic neutral lipid that gives the cytoplasm a vacuolated and foamy appearance. These tumors are usually hormone receptors negative and Her-2 Neu positive. Here, we report a case of lipid-rich breast carcinoma which showed hormone receptor positivity and Her-2 Neu negative.

Development and Differentiation of Epididymal Epithelial Cells in Korean Native Black Goat

Simple Summary

Studies have revealed that the communication networks among epididymal epithelial cells play an essential role in sperm maturation and storage. Therefore, the localization and expression of V-ATPase and cytokeratin 5 in the clear cells and basal cells, respectively, of immature and mature goat epididymis was investigated. To the best of our knowledge, the present study is the first to use immunofluorescence labeling and confocal imaging to characterize the differentiation of clear cells and basal cells in the goat epididymis. The findings could help the understanding of the regulatory mechanism that creates an optimal luminal environment for sperm maturation and storage in the epididymis.

Abstract

The acidic luminal environment of the epididymis is regulated by the communication networks among epididymal epithelial cells; it is necessary for sperm maturation and storage. To characterize epididymal epithelial cell differentiation, the localization and expression of hydrogen-pumping vacuolar ATPase (V-ATPase) and cytokeratin 5 (KRT5) in the clear and basal cells, respectively, of immature and mature goat epididymis and vas deferens was examined. The epididymides and vas deferens were obtained from goats aged 1, 2, and 12–14 months. To assess the localization and expression patterns of V-ATPase and KRT5 in the caput, corpus, and cauda of the epididymis and proximal vas deferens, the tissue sections were subjected to immunofluorescence labeling and observed by confocal microscopy. Both clear and basal cells progressively started to differentiate in a retrograde manner. Clear cells disappeared from the cauda region after puberty, and they were maintained only in the caput and corpus regions of the adult goat epididymis. V-ATPase and KRT5 were co-expressed in the differentiated cells located at the base of the epithelium (i.e., basal cells). This cell type-specific differentiation and distribution of the epithelial cells plays a critical role in establishing a unique luminal environment for sperm maturation and storage in the goat epididymis.

The current clinical approach to newly diagnosed uterine cancer

INTRODUCTION

Uterine cancer is the most common gynecologic malignancy, although fortunately, 75% of women present with early-stage disease. A major area of controversy regarding the management of the disease concerns postoperative therapy for both women with early- and advanced-stage endometrial carcinoma. Here, we review landmark evidence that can help guide clinical decision-making in the treatment of women diagnosed with endometrial cancer.

AREAS COVERED

In this review, we present the latest data driving decisions for both surgical management and postoperative therapy for women with endometrial carcinoma. Areas discussed include surgical staging, with a specific discussion on the role of sentinel lymph node mapping, and postoperative therapy, ranging from the data supporting observation for women with early-stage, low-risk disease to combination therapy for women with advanced disease. Less common histologies, such as serous and clear cell carcinoma, as well as carcinosarcoma, will also be covered. Furthermore, a section of the paper is dedicated to the current state of fertility-sparing surgery.

EXPERT OPINION

We suggest several approaches for deciding on adjuvant therapy, based on stage and histology, after comprehensive surgical staging. The role that endometrial cancer molecular subtypes will play on postoperative therapy remains to be fully investigated.