Synchronous clear cell renal cell carcinoma and tubulocystic carcinoma: genetic evidence of independent ontogenesis and implications of chromosomal imbalances in tumor progression

Seven percent of renal cell carcinoma (RCC) cases are diagnosed as "unclassified" RCC by morphology. Genetic profiling of RCCs helps define renal tumor subtypes, especially in cases where morphologic diagnosis is inconclusive. This report describes a patient with synchronous clear cell RCC (ccRCC) and a tubulocystic renal carcinoma (TCRC) in the same kidney, and discusses the pathologic features and genetic profile of both tumors. A 67 year-old male underwent CT scans for an unrelated medical event. Two incidental renal lesions were found and ultimately removed by radical nephrectomy. The smaller lesion had multiple small cystic spaces lined by hobnail cells with high nuclear grade separated by fibrous stroma. This morphology and the expression of proximal (CD10, AMACR) and distal tubule cell (CK19) markers by immunohistochemistry supported the diagnosis of TCRC. The larger lesion was a typical ccRCC, with Fuhrman's nuclear grade 3 and confined to the kidney. Molecular characterization of both neoplasms using virtual karyotyping was performed to assess relatedness of these tumors. Low grade areas (Fuhrman grade 2) of the ccRCC showed loss of 3p and gains in chromosomes 5 and 7, whereas oncocytic areas displayed additional gain of 2p and loss of 10q; the high grade areas (Fuhrman grade 3) showed several additional imbalances. In contrast, the TCRC demonstrated a distinct profile with gains of chromosomes 8 and 17 and loss of 9. In conclusion, ccRCC and TCRC show distinct genomic copy number profiles and chromosomal imbalances in TCRC might be implicated in the pathogenesis of this tumor. Second, the presence of a ccRCC with varying degrees of differentiation exemplifies the sequence of chromosomal imbalances acquired during tumor progression

Sarcoma sinovial monofásico con componente intraneural.: Informe de un caso con expresión inmunohistoquímica del factor de transcripción TLE-1 y presencia de translocación t (X;18) (SYT-SX1)

Synovial sarcoma is a high-grade neoplasm, of uncertain histogenesis, which comprises 5- 10% of all soft tissue sarcomas, and occurs, most frequently in the lower extremities. Intraneural location is extremely rare and it has only been reported in nine cases. The differential diagnosis of an intraneural SS is established with fibrosarcoma and malignant peripheral nerve sheath tumor. Positive immunostaining for cytokeratins and EMA is helpful but may be non-specific. Positive immunostaining for TLE-1 (Transducin-Like Enhancer of split 1) has great sensibility and specificity for the diagnosis of SS. Molecular analysis has a better specificity for diagnosis, because t(X;18)(SYT-SSX ) translocation, may be found in >80% of cases. We report herein, a case of a soft tissue monophasic SS, of a 20 years-old women, which presented a focal intraneural component, affecting the endoneurium of the cyatic nerve. The tumor expressed by immunohistochemistry TTL-1 and molecular analysis identified SYT-SSX1 translocation, allowing exclusion of other possible diagnosis. We review the concept related to the SS cellular origin. Pain, which is a significant clinical feature of SS, the gross relationship to nerve, the intraneural component present in some cases, the histological similarity with nerve sheath tumors, and the presence of calcospherites, unmyelinated fibers and endoneurial-like mucous, support the hypothesis of a possible intraneural origin.El sarcoma sinovial es una neoplasia de alto grado, de histogénesis incierta, que representa el 5-10% de todos los sarcomas blandos, y afecta más frecuentemente las extremidades inferiores. La localización intraneural es extremadamente rara y solamente hay informados nueve casos. El diagnóstico diferencial de los SS intraneurales se establece con fibrosarcoma y con el tumor de vaina nerviosa periférica maligno. La inmunomarcación positiva para las citoqueratinas y el EMA es de ayuda pero puede ser no específica. La inmunomarcación positiva para TLE-1 (Transducin-Like Enhancer of split 1) tiene gran sensibilidad y especificidad para el diagnóstico de los SS. El análisis molecular tiene mejor especificidad para el diagnóstico, porque la translocación t(X;18)(SYT-SSX) se puede encontrar hasta en el 80% de casos. Informamos en este estudio un caso de un SS monofásico de tejidos blandos del muslo, en una mujer de 20 años, que presentó un componente intraneural, afectando el endoneuro del nervio ciático. El tumor expresó por inmunohistoquímica TTL-1 y el análisis molecular identificó la translocación SYT-SSX1, permitiendo la exclusión de otros diagnósticos posibles. Revisamos el concepto relacionado con el origen celular de los SS. El dolor, que es una característica clínica presente en los SS, la relación macroscópica con nervios, el componente intraneural presente en algunos casos, la semejanza histológica con los tumores de la vaina nerviosa periférica, y de la presencia de los calcosferitas, fibras amielínicas y el moco semejante al endoneural, apoyan la hipótesis de un posible origen intraneura

JCPyV T-Antigen Activation of the Anti-Apoptotic Survivin Promoter—Its Role in the Development of Progressive Multifocal Leukoencephalopathy

Progressive Multifocal Leukoencephalopathy (PML) is a fatal demyelinating disease of the CNS, resulting from the lytic infection of oligodendrocytes by the human neurotropic polyomavirus JC (JCPyV), typically associated with severe immunocompromised states and, in recent years, with the use of immunotherapies. Apoptosis is a homeostatic mechanism to dispose of senescent or damaged cells, including virally infected cells, triggered in the vast majority of viral infections of the brain. Previously, we showed upregulation of the normally dormant anti-apoptotic protein Survivin in cases of PML, which—in vitro—resulted in protection from apoptosis in JCPyV-infected primary cultures of astrocytes and oligodendrocytes. In the present study, we first demonstrate the absence of apoptotic DNA fragmentation and the lack of caspase activity in 16 cases of PML. We also identified the viral protein large T-Antigen as being responsible for the activation of the Survivin promoter. Chromatin Immunoprecipitation assay shows a direct binding between T-Antigen and the Survivin promoter DNA. Finally, we have identified the specific region of T-Antigen, spanning from amino acids 266 and 688, which binds to Survivin and translocates it to the nucleus, providing evidence of a mechanism that results in the efficient replication of JCPyV and a potential target for novel therapies

Follicular Adenoma with Extensive Extracellular Mucin Deposition: Report on Two Cases

We report two cases of follicular adenoma of the thyroid with extensive extracellular mucin deposition. Fine needle aspiration in Case 1 showed singly discohesive polygonal cells in a granular mucinous background. They contained abundant eosinophilic cytoplasm, nuclear irregularities, and frequent nuclear inclusions with occasional bizarre mitoses. A right lobectomy was done. In Case 2, a 47-year-old Caucasian woman with multinodular goiter had total thyroidectomy and a yellow-tan nodule was found within the right lobe. Both tumors were well-encapsulated masses with thick capsules. Each was characterized by microfollicles without papillae in a mucinous stroma. Tumor cells were positive for thyroglobulin and negative for calcitonin, CEA, galectin-3, HBME-1, and CK19. The extracellular mucin stained with Alcian-blue and colloidal iron but not with mucicarmine and D-PAS. No BRAF gene mutation was detected. Because there were neither capsular nor vascular invasions, both cases were diagnosed as follicular adenomas of the thyroid with extensive extracellular mucin deposition, which as proposed by the WHO classification can be categorized as a mucinous variant of follicular adenoma. Retrospectively, frequent nuclear inclusions and the absence of nuclear grooves in the mucin-containing background of cytologic smears and histologic sections were shared by those of mucin-producing papillary carcinoma. It is unclear whether it belongs to an existing category of thyroid neoplasm with mucin production or whether it is truly a new tumor variant. Furthermore, pathologists should pay attention to avoid misdiagnosis of this variant of follicular neoplasm that shows an overlapping cytology with that of papillary carcinoma

CCL8/MCP-2 is a target for mir-146a in HIV-1-infected human microglial cells

MicroRNA-mediated regulation of gene expression appears to be involved in a variety of cellular processes, including development, differentiation, proliferation, and apoptosis. Mir-146a is thought to be involved in the regulation of the innate immune response, and its expression is increased in tissues associated with chronic inflammation. Among the predicted gene targets for mir-146a, the chemokine CCL8/MCP-2 is a ligand for the CCR5 chemokine receptor and a potent inhibitor of CD4/CCR5-mediated HIV-1 entry and replication. In the present study, we have analyzed changes in the expression of mir-146a in primary human fetal microglial cells upon infection with HIV-1 and found increased expression of mir-146a. We further show that CCL8/MCP-2 is a target for mir-146a in HIV-1 infected microglia, as overexpression of mir-146a prevented HIV-induced secretion of MCP-2 chemokine. The clinical relevance of our findings was evaluated in HIV-encephalitis (HIVE) brain samples in which decreased levels of MCP-2 and increased levels of mir-146a were observed, suggesting a role for mir-146a in the maintenance of HIV-mediated chronic inflammation of the brain.—Rom, S., Rom, I., Passiatore, G., Pacifici, M., Radhakrishnan, S., Del Valle, L., Piña-Oviedo, S., Khalili, K., Eletto, D., Peruzzi, F. CCL8/MCP-2 is a target for mir-146a in HIV-1 infected human microglial cells

Effects of JC Virus Infection on Anti-Apoptotic Protein Survivin in Progressive Multifocal Leukoencephalopathy

Progressive multifocal leukoencephalopathy (PML) is a fatal demyelinating disease of the central nervous system resulting from the productive infection of oligodendrocytes by the opportunistic polyomavirus JC virus (JCV). Apoptosis is a host defense mechanism to dispose of damaged cells; however, certain viruses have the ability to deregulate apoptotic pathways to complete their life cycles. One such pathway involves survivin, a member of the inhibitor of apoptosis family, which is abundantly expressed during development in proliferating tissues but should be absent in normal, terminally differentiated cells. Immunohistochemistry performed in 20 cases of PML revealed the presence of survivin in JCV-infected oligodendrocytes and bizarre astrocytes within demyelinated plaques. Survivin up-regulation was also found in oligodendroglial and astrocytic cultures infected with JCV. Cell cycle analysis and DNA laddering demonstrated a significantly lower number of cells undergoing apoptosis on JCV infection compared with noninfected cultures; small interfering RNA inhibition of survivin resulted in a dramatic increase in apoptotic cells in JCV-infected cultures. This is the first report describing the activation of survivin by JCV infection in vitro and in PML clinical cases. These observations provide new insights into the anti-apoptotic mechanisms used by JCV to complete its lytic cycle and may suggest new therapeutic targets for PML