Are molecular features of a chromophobic cell renal cell carcinoma correlated with clinical findings?

Lipids extracted from three human renal neoplasms have been characterized by means of 13C magnetic resonance spectroscopy. The presence of free cholesterol, high levels of unsatured fatty acids, and phosphatidylcholine, and a very high fatty acids/cholesterol ratio makes the lipid profile of a rare chromophobe cell carcinoma very similar to that of an oncocytoma. On the contrary, clear cell carcinomas are mainly characterized by the presence of almost fully esterified cholesterol and by a markedly lower level of unsatured fatty acids. Since chromophobic cell carcinomas have a more favourable prognosis than clear cell carcinomas, their analogy in the lipid composition with a benign renal neoplasm could have a clinical significance. In particular, our report suggests that cholesteryl esters and high levels of unsatured fatty acids could be a marker of a poor (clear cell carcinomas) or a good (chromophobic cell carcinomas) prognosis, respectively. More in depth studies are required of the molecular composition of the neoplastic pathologies that add new knowledge, with potential clinical implications.     

Origin of clear cell carcinoma: nature or nurture?

A rare but serious complication of endometriosis is the development of carcinoma, and clear cell and endometrioid carcinomas of the ovary are the two most common malignancies which arise from endometriosis. They are distinct diseases, characterized by unique morphologies, immunohistochemical profiles, and responses to treatment. However, both arise in endometriosis and can share common mutations. The overlapping mutational profiles of clear cell and endometrioid carcinomas suggest that their varied histologies may be due to a different cell of origin which gives rise to each type of cancer. Cochrane and colleagues address this question in a recent article in this journal. They show that a marker of ovarian clear cell carcinoma, cystathionine gamma lyase, is expressed in ciliated cells. Similarly, they show that markers of secretory cells (estrogen receptor and methylenetetrahydrofolate dehydrogenase 1) are expressed in ovarian endometrioid carcinoma. Taken together, they suggest that endometrioid and clear cell carcinomas arise from cells related to secretory and ciliated cells, respectively. We discuss Cochrane et al's work in the context of other efforts to determine the cell of origin of gynecological malignancies, with an emphasis on recent developments and challenges unique to the area. These limitations complicate our interpretation of tumor differentiation; does it reflect nature imposed by a specific cell of origin or nurture, by either mutation(s) or environment? Copyright © 2017 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.     

Osteopontin expression correlates with nuclear factor-κB activation and apoptosis downregulation in clear cell renal cell carcinoma

Osteopontin (OPN) is a phosphoglycoprotein implicated in tumorigenesis and tumor cell metastasis. Apoptosis inhibition is one of the mechanisms that contribute to development and progression of cancer, and might be initiated by OPN interaction with tumor cells. The aim of this study was to analyze the relation between OPN and nuclear factor-kappa B (NF-κB) expression in clear cell renal cell carcinoma (CCRCC), as well as their relation to apoptotic activity of tumor cells.Expression of OPN protein and p65 NF-κB subunit was analyzed immunohistochemically in 87 CCRCC samples, and compared mutually and with apoptotic index. Expression of OPN mRNA was analyzed using quantitative real-time PCR and compared with OPN and NF-κB protein expression in 22 CCRCC samples.Statistical analysis showed an association of p65 NF-κB with OPN mRNA (p = 0.015) and protein (p < 0.001). Also, we found an inverse relationship of OPN with NF-κB protein expression and apoptotic activity of tumor cells (p = 0.006 and p = 0.022, respectively). Our results indicate that p65 NF-κB signaling pathway may be involved in OPN-mediated CCRCC progression, partly by protecting tumor cells from apoptosis. Therefore, both molecules can constitute potential targets for therapeutic intervention in CCRCC.     

Clear cell changes in mucinous tubular and spindle cell carcinoma: cytoplasmic pallor/clearing within tubules,vacuoles or hybrid conventional clear cell carcinoma of kidney?

Mucinous tubular and spindle cell carcinoma (MTSCC) is a rare and recently recognized subtype of renal cell carcinoma (RCC). Apart from the classic morphology comprising conventional three components, there exist a large number of non-classic morphological variants of MTSCC, which make it necessity to differentiate from other RCC. Herein, we report two non-classic morphological variants of MTSCC. Case 1, a 85 years old man, showed numerous vacuoles among inherent components and cytoplasmic pallor/clearing within tubules mimicking conventional clear cell RCC with a 8.5 years follow-up, while Case 2 indicated a “mucin-poor” MTSCC associated with simultaneous conventional clear cell RCC at her age of 73 years. Until now Case 1 carries the longest disease-free survival reported in literature since MTSCC was defined and ranks the oldest since reported in literature, while Case 2 is the first report of “mucin-poor” MTSCC associated with simultaneous conventional clear cell RCC. Now, since no biomarkers or imagining tools but pathological examination can confirm the diagnosis of MTSCC, the management is always following the guideline of RCC in clinical practice. Generally, most reports consider it as a good prognosis disease, but sarcomatoid variant, even classic subtype can progress rapidly to life-threatening disease.     

Does human papillomavirus play a role in the development of bladder transitional cell carcinoma? A comparison of PCR and immunohistochemical analysis

AIM: To investigate the role of human papillomavirus (HPV) in the development of bladder transitional cell carcinoma (TCC). METHODS: Seventy eight paraffin wax embedded TCC samples were tested for the presence of HPV by two methods. First, immunohistochemistry was carried out using a polyclonal antibody capable of detecting the capsid protein of all known papillomaviruses. The second method was a consensus GP5+/6+ primer mediated polymerase chain reaction (PCR) technique, with the products analysed by both agarose gel electrophoresis and an enzyme immunoassay using type specific oligonucleotide probes for 10 different mucosal genotypes. To exclude false negative results because of the poor quality of DNA extracted from paraffin wax embedded samples, the series was extended to include 20 further blocks for which the corresponding snap frozen unfixed tissue was available. RESULTS: The two methods produced contrasting results, with 47 of the 78 samples positive for HPV antigen and none positive for HPV DNA. HPV DNA was not detected in the 20 additional paraffin wax embedded TCCs or in the 20 paired unfixed samples. In contrast, HPV DNA was amplified by PCR from all six of the paraffin wax embedded cervical carcinoma and anogenital wart control samples. CONCLUSION: The disparity between the two sets of results is probably caused by false positives resulting from the non-specificity of the polyclonal antibody used for immunohistochemistry. These results suggest that HPV is unlikely to play an aetiological role in the development of bladder TCC.     

Underactivation of the adiponectin–adiponectin receptor 1 axis in clear cell renal cell carcinoma: implications for progression

Energy-sensing pathways, normally coordinated by 5′ AMP-activated protein kinase (AMPK), are dysregulated in renal cell carcinoma (RCC). Obesity can accentuate the pre-existing pro-tumorigenic metabolic machinery in RCC cells through its associated obesogenic hormonal milieu, characterized by lower circulating levels of adiponectin. In RCC patients, low adiponectin levels associate clinically with more aggressive disease. We investigated the adiponectin signaling pathway in RCC, focusing on adiponectin receptor 1 (AdipoR1) and associated activation of AMPK. AdipoR1 protein in RCC and normal surrounding renal tissues was determined by Western blot analysis and immunohistochemistry. Anti-tumorigenic effects of adiponectin in RCC cells in vitro were investigated via VEGF and MMP ELISA and invasion assays. Using in vivo models of RCC, the effect of AdipoR1-knockdown (shRNA) on tumor latency, growth and dissemination were determined. AdipoR1 protein was significantly reduced in clear cell RCC specimens. Adiponectin treatment inhibited VEGF, MMP-2 and MMP-9 secretion and activity and invasive and migratory capacities of RCC cells. AMPKα1-knockdown (shRNA) attenuated adiponectin’s effects. In cells stably expressing AdipoR1-specific shRNA, AMPK activation by adiponectin was significantly reduced compared to cells expressing control shRNA. In vivo, AdipoR1 knockdown increased the growth, dissemination and angiogenesis of RCC. These findings suggest that deficiencies in the entire adiponectin hormonal axis (the hormone and its receptor) result in underactivation of AMPK leading to increased angiogenic and invasive capacities of RCC. The established link between obesity and RCC can therefore be further explained by the adiponectin deficiency in obese individuals together with reduced AdipoR1 protein in RCC.     

Congenital “clear cell sarcoma of the kidney”

At 31 weeks gestation, a hydropic male fetus died in utero with metastatic disease from a renal clear cell sarcoma. The tumor had metastasized to para–aortic and mediastinal lymph nodes, lung, pleura, and liver, leading to superior vena cava obstruction and pulmonary hypoplasia. The pathologic findings and cytogenetic analysis of the fetus and tumor are presented. In addition, review of the literature reveals six other cases aged <6 months of age, including two extrarenal cases.     

Pediatric renal cell carcinomas: where do they fit in the new histologic classification of renal cell carcinoma?

Genetic, immunohistochemical, and histologic data has led to the reclassification of renal cell carcinoma in the last decade. Recent studies suggest that renal cell carcinomas in children and young adults may represent a distinct group of tumors. These tumors have unique genetic findings (most commonly t(x;1)(p11:q21)), a predominantly papillary architecture, numerous calcifications, granular cytoplasm, and a possible relationship with neuroblastoma.     

Oral variant of acantholytic squamous cell carcinoma—Histochemical and immunohistochemical features

Acantholytic squamous cell carcinoma (ASCC) is an uncommon variant of squamous cell carcinoma (SCC). It is characterized by a combination of typical SCC and pseudoglandular structures, dyskeratotic cells and prominent acantholysis.The purpose of this study was to analyze the histochemical and immunohistochemical characteristics of the intraoral variant of ASCC. Cases of intraoral ASCC were retrieved from the English language literature. Four new cases from our files were added.In total, 35 cases were included and analyzed in this study. The mean age of the patients was 61.5 + 13 years (age range 38–92 years), with a male-to-female ratio of 1.7:1. According to the available data, histochemical and immunohistochemical stains for mucins were found to be consistently negative. E- cadherin, a marker of adherens junctions, was usually reported to be expressed in areas of “typical” (non acantholytic) SCC, but reduced in the acantholytic areas. We examined for the first time the expression of claudin 1, a marker of tight junctions, and found it to be reduced in the acantholytic areas, similar to E-cadherin. Several cases of oral ASCC also expressed vimentin and cytokeratin (CK) 19, markers associated with epithelial-mesenchymal transition. A wide range of non-epithelial markers yielded negative immunoreactions.In conclusion, ASCC is an uncommon variant of squamous cell carcinoma. The acantholytic process appears to involve reduced expression of molecular components of both adherens junctions and tight junctions. These findings could suggest a relation to the epithelial mesenchymal transition process and therefore further studies are needed in order to establish such a link and the subsequent possible impact on the clinical outcome of the patients.     

Are oestrogens and genetic predisposition etiologic factors in the development of clear cell carcinoma of the peritoneum?

A literature search was carried out for clinical observations that could explain the possible aetiology of primary peritoneal clear cell carcinoma (CCC) including diagnostic dilemmas, various theories of origin, oestrogen dependence and genetic association. It was found to be an extremely rare tumour (CCC) arising in the peritoneum and is often misdiagnosed as mesothelioma or serous carcinoma or metastatic adenocarcinoma due to overlapping morphological features. The awareness of such dilemmas is important even before making a diagnosis. Clinicopathological features and immunohistochemical studies like WT1, CK20 and calretinin are usually helpful in differentiating CCC from serous carcinoma, metastatic carcinoma from bowel and mesothelioma. (CK7 is common to all epithelial tumours, CEA can be expressed in clear cell carcinoma, WT1 is normally expressed in serous carcinoma, calretinin is expressed in mesothelioma and CK20 in colon carcinoma). The distinction between the above tumours is important as correct diagnosis is required in initiating appropriate treatment.