Detection of a germline mutation and somatic homozygous loss of the von Hippel-Lindau tumor-suppressor gene in a family with a de novo mutation. A combined genetic study, including cytogenetics, PCR/SSCP, FISH, and CGH

von Hippel-Lindau (VHL) disease is a pleiotropic disorder featuring a variety of malignant and benign tumors of the eye, central nervous system, kidney, and adrenal gland. Recently the VHL gene has been identified in the chromosomal region 3p25-26. Prognosis and successful management of VHL patients and their descendants depend on unambiguous diagnosis. Due to recurrent hemangioblastomas, a29-year-old patient without familial history of VHL disease was diagnosed to be at risk for the disease. Histopathological examination of a small renal mass identified a clear cell tumor with a G1 grading. Genetic characterization of the germline and of the renal tumor was performed. Polymerase chain reaction/single strand conformation polymorphism (PCR/SSCP) analysis with primers from the VHL gene identified a deletion of a single nucleotide in exon 2 in the patient's germline and in the tumor, but not in the DNA of his parents. This deletion therefore must be a de novo mutation. Comparative genome hybridization (CGH) and fluorescence in situ hybridization (FISH) analysis of the G1 tumor with differentially labelled yeast artifical chromosome (YAC) clones showed loss of 3p and of the 3p26 signals, respectively. In conclusion, we identified a de novo germline mutation in the VHL gene of a young patient and a somatic chromosome 3p loss at the homologous chromosome 3 in his renal tumor. Our results suggest a recessive mode of inactivation of the VHL gene, providing solid evidence for its tumor-suppressor gene characteristics. Our data show the diagnostic potential of genetic testing, especially in patients without VHL family history. Furthermore, the findings of homozygous inactivation of the VHL gene in a G1 tumor support the notion that the inactivation of the VHL gene is an early event in tumorigenesis of renal cell carcinoma.

[Comparative genomic hybridization in pathology. A new molecular cytogenetic method]

Comparative genomic hybridisation (CGH) is a new cytogenetic method, which is based on a combination of fluorescence microscopy and digital image analysis. The molecular genetic basis is the hybridization of a mixture of fluorescein labeled test-DNA and reference-DNA on normal metaphase chromosomes. Comparative analysis allows the identification of all unbalanced chromosomal aberrations of the test-DNA in a single experimental step. The resulting DNA gains or DNA losses on the chromosomal or subchromosomal level mirror possible amplifications of oncogenes or losses of suppress orgenes. As CGH can be performed with genomic DNA of formalin-fixed and fresh-frozen tissue or cells, this new method is a very effective tool for pathologists and cytologists in the extended genomic screening of tumors and genetically altered tissues. Despite CGH analysis at present is restricted to research applications; its widespread dissemination as a routine method in diagnostic pathology can be expected in the near future.

Intraoperative evaluation of renal cell carcinoma: a prospective study of the role of ultrasonography and histopathological frozen sections

PURPOSE

Nephron sparing surgery is being performed increasingly for treatment of renal cell carcinoma, including in select patients with a normal contralateral kidney. The number of tumors in the involved kidney (single versus multiple) and presence or absence of perinephric fat involvement (pathological stage T1 to 2 versus T3A) are important prognostic factors. In a prospective study we evaluated the accuracy of intraoperative histopathological frozen section analysis of renal capsular biopsies for assessing local tumor stage, and the accuracy of intraoperative ultrasonography for assessing tumor focality.

MATERIALS AND METHODS

Intraoperative frozen section biopsies and ultrasonography were compared with information obtained from preoperative computerized tomography (CT), intraoperative inspection of the kidney by the surgeon and permanent histopathological specimens.

RESULTS

We evaluated 99 patients (102 kidneys) with localized sold renal masses undergoing either radical nephrectomy (48) or nephron sparing surgery (54). Final pathological analysis revealed 95 renal cell carcinomas (stage T3A in 24), 6 oncocytomas and 1 angiomyolipoma. Multiple tumors were detected in 18 of 102 kidneys overall. Frozen section analysis identified 87% of the stage T3A lesions with no false-positive results, compared to CT, which only identified 67%. Ultrasonography identified 14 of 18 multifocal tumors (78%) and was not more accurate than the combination of CT and intraoperative inspection. However, during nephron sparing surgery ultrasonography was useful to localize the intrarenal extent of tumors (17 cases).

CONCLUSIONS

Our results clarify the role of intraoperative ultrasonography and frozen section analysis in patients undergoing nephron sparing surgery for renal cell carcinoma. Frozen section analysis may be useful in select patients with small peripheral tumors who are under consideration for elective nephron sparing surgery.

Expression of CD44 isoforms in renal cell tumors. Positive correlation to tumor differentiation

CD44 isoforms have been implicated in tumor progression and embryogenesis. Primary renal cell tumors (n = 100) of various histopathological differentiation and grading stages were analyzed for expression of CD44 isoforms in comparison with nonmalignant adult and fetal renal tissues. Evaluations were performed by immunohistochemistry using CD44 isoform-specific monoclonal antibodies and by reverse transcriptase polymerase chain reactions (RT-PCR). In the nonmalignant kidney no CD44 variant isoforms were detected. There was a significant increase in expression of CD44 standard (CD44s) and several variant isoforms (CD44v) in the course of tumor differentiation in clear cell carcinomas (n = 68) from stages G1 to G3 (P < 0.0001 for CD44s and isoforms containing CD44-6v, and P < 0.007 for those containing CD44-9v). Also, in chromophilic cell carcinomas (n = 13), CD44 isoform expression correlated with grading; ie, no CD44 expression was detected in G1 tumors, whereas in approximately 50% of the G2 tumors, CD44s, CD44-6v, and CD44-9v isoforms were present. Oncocytomas (n = 8), which are benign renal cell tumors, did not express CD44 isoforms, whereas invasive chromophobe cell carcinomas (n = 11) were positive for CD44s and CD44v isoforms. Transcript analyses by RT-PCR revealed that the upregulated isoforms in the carcinoma cells contained exons 8 to 10 and 3, 8 to 10 in combination from the variant region. In conclusion, expression of variant CD44 isoforms was strongly correlated with grading and appears to mediate a more aggressive phenotype to renal cell tumors.

Cytogenetic studies in renal cell carcinoma patients receiving low-dose recombinant interleukin-2-based immunotherapy

A variety of cytogenetic aberrations have been reported in sporadic and familial renal cell carcinoma. Rearrangements of the short arm of chromosome 3 (3p), trisomy 17, and nuclear hyperdiploidy have been reported to be common clonal chromosome changes. We analyzed a total of ten tumor-derived cell lines from patients who underwent nephrectomy for renal cell carcinoma employing conventional cytogenetics. All patients received an immunomodulatory therapy based on recombinant interleukin-2 (rIL-2). Tumor stage and grade, histo- and cytopathology, and patients' response to immunotherapy were assessed and correlated statistically to rearrangement of 3p, trisomy 17, and nuclear hyperdiploidy. Trisomy 17 as clonal aberration could be revealed only in papillary renal cell carcinoma, whereas tumors with compact or tubulopapillary growth pattern lacked this abnormality (p < 0.002). One of 3 patients with diploid or near-diploid karyotype (< or = 49 chromosomes) achieved a partial remission while two presented with stable disease after immunotherapy. In contrast, all 6 patients with tumor progression upon rIL-2-based immunotherapy revealed hyperdiploid (> 49 chromosomes) karyotypes. The correlation between hyperdiploidy and tumor progression was found to be statistically significant (p < 0.029). Interestingly, the only patient achieving an objective tumor remission after immunotherapy presented with a normal diploid karyotype. Our findings suggest tumor hyperdiploidy as an adverse prognostic factor in renal cell carcinoma patients receiving rIL-2-based immunotherapy.

Chromosomal abnormalities in non-neoplastic renal tissue

Chromosome aberrations were studied in short-term cultures of non-neoplastic renal tissue and tumor tissue in 60 patients, 41 male and 19 female, with renal cell cancer (RCC), and in normal renal parenchyma from two cases, one male and one female, at autopsy with non-kidney related disease. Cytogenetic analysis of the non-neoplastic renal tissue from the patents with RCC revealed clonal chromosome aberrations in 32 of 60 (53%) cases: -Y, +Y, +X, +5, +7, +10, +12, +13, +18, +21, and del(9)(q12). In all other cases, non-clonal numerical and structural chromosome aberrations were observed, except for three cases of culture failure. Forty-two cases of RCC yielded clonal chromosomal abnormalities. Trisomy 7 was present in 23 cases, loss of Y in 14, trisomy 5 and 12 in three, trisomy 18 in two cases, and trisomy 10 in one case. Clonal chromosomal anomalies found in two cases from kidneys without neoplasia were trisomy 7, trisomy 12, and trisomy 18 in one case, and monosomy of chromosome 15 in the other. The proportion of aberrant cells in both cases (with clonal and non-clonal aberrations) was, on average, 24%. Apparently, chromosomal abnormalities only play a role in the process of oncogenesis when they are in the appropriate stage and lineage of differentiation.

[Standardized documentation of patho-anatomic findings using ADT (Association of German Tumor Centers) tumor forms for malignancies of the mouth, jaw and face (version III)]

The documentation form for pathohistologic findings (version III) for tumors of the maxillofacial region is presented. It is part of the site-specific documentation of the German Association of Tumor Centers (ADT). Its handling is explained by instructions which are based on the ICD-O classification and the TNM system. The prognostic relevance of the standardized documentation has already been proven by various histomorphologic investigations concerning oral and oropharyngeal cancer. By means of a multicentric observational study the German Austrian Swiss co-operative group DOSAK will develop a new prognostic model for oral and oropharyngeal cancer.

Carcinoid in a horseshoe kidney. Morphology, immunohistochemistry, and cytogenetics

Renal carcinoids are very rare neoplasms. We were able to culture and subsequently karyotype a carcinoid located in the isthmus of a horseshoe kidney, which revealed the following chromosomal pattern: 47,XX, + 13[8]/46,XX,t(13;14)(q31;q11.2)[5]/46,XX[2]. The DNA index was 1. Our results, compared with the sparse data from the literature, suggest that carcinoid of the kidney has no cytogenetic aberrations in common with carcinoids from other anatomical sites reported. On the other hand, numerical and structural aberrations of chromosome 13 seem to play a crucial role in the development of metanephric-derived renal tumors.

Microscopic evaluation of an occluded intracoronary Palmaz-Schatz stent removed before coronary artery bypass grafting

Intracoronary implantation of stent devices is a new interventional technique with a promising role in the treatment of acute coronary occlusions caused by intimal dissection and suboptimal results of percutaneous transluminal coronary angioplasty. However, the prolonged presence of stent material embedded in the arterial wall may generate unknown late consequences. Major complications consist of subacute to chronic occlusion and restenosis. To elucidate the underlying cause we removed an angiographically occluded intracoronary artery Palmaz-Schatz stent before coronary artery bypass grafting. Scanning electron microscopy showed thorough coating of the metal struts of the stent by normal neoendothelial cells. Side branches arising at the level of the stent were patent. According the specific angiographic feature thrombotic occlusion originated distally of the stent.

Distinct Xp11.2 breakpoints in two renal cell carcinomas exhibiting X;autosome translocations

Several human renal cell carcinomas with X;autosome translocations have been reported in recent years. The t(X;1)(p11.2;q21) appears to be a specific primary anomaly, suggesting that tumors with this translocation form a distinct subgroup of RCC. Here we report two new cases, one with a t(X;10)(p11.2;q23), the other with a t(X;1)(p11.2;p34). The common breakpoint in Xp11.2 suggests that they belong to the above-mentioned subset of RCC. Using FISH in conjunction with X-specific YAC clones, we demonstrate that the two new cases exhibited distinct breakpoints within Xp11.2.

Morphological classification of renal cancer

The current classification of renal-cell adenomas (RCAs) and carcinomas (RCCs) is based on eight basic cell and tumor types (entities) with characteristic morphologic features: (1) RCCs of clear-cell type, (2) RCAs/RCCs of chromophilic-cell type, (3) RCAs/RCCs of chromophobic-cell type, (4) RCCs of duct Bellini type, (5) RCCs of transitional-cell type, (6) RCCs of neuroendocrine type, (7) RCAs of oncocytic type, and (8) RCAs of metanephroid type. Tumors with a proposed histogenesis from the proximal tubule (clear-cell and chromophilic tumors) amount to 85% of renal cancers, whereas tumors with a proposed histogenesis from the connecting tubule/collecting duct (chromophobic-, oncocytic-, and duct Bellini-type tumors) amount to only 11%. The remaining tumor types represent rare entities (less than 1% each). Tumor cytogenetics data confirm the proposed eight morphologic subtypes and give further indications for type-specific tumor development and progression.

Administration of interleukin 12 in combination with type II collagen induces severe arthritis in DBA/1 mice

The induction of arthritis in DBA/1 mice usually requires immunization with the antigen type II collagen emulsified with Mycobacterium tuberculosis in oil. Here we describe that interleukin 12 (IL-12) can replace mycobacteria and cause severe arthritis of DBA/1 mice when administered in combination with type II collagen. Immunization of DBA/1 mice with type II collagen emulsified in oil alone resulted in a weak immune response, and only a few animals (10-30%) developed arthritis. Administration of IL-12 for 5 days simultaneously with each immunization strongly enhanced the anti-type II collagen immune response. Collagen-specific interferon gamma (IFN-gamma) synthesis by ex vivo activated spleen cells was enhanced 3- to 10-fold. IFN-gamma was almost completely produced by CD4+ T cells. Furthermore, the production of collagen-specific IgG2a and IgG2b antibodies was upregulated 10- to 100-fold. As a consequence, the incidence of arthritis in the group of mice immunized with collagen plus IL-12 was very high (80-100%). The developing arthritis was severe, involving approximately 50% of all limbs with strongly increased footpad thickness in most cases. Furthermore, histological examination revealed massive, mainly polymorphonuclear cell infiltration, synovial hyperplasia, cartilage and bone destruction, as well as new bone formation. In many cases, this resulted in the complete loss of joint structure. Neutralization of IFN-gamma in vivo prevented the development of arthritis in collagen-immunized and IL-12-treated mice. In conclusion, our data show that in vivo administered IL-12 can profoundly upregulate a T helper I-type autoimmune response, resulting in severe joint disease in DBA/1 mice.

Posttransfusional, LKM-1-autoantibody-positive hepatitis C virus infection, cryoglobulinemia, and aplastic anemia

Aplastic anemia is occasionally caused by viral hepatitis, hepatitis C virus being the most important factor. Pathogenetically, decreased bone marrow function, abnormalities of the bone marrow microenvironment, and immune-mediated suppression of hematopoiesis are important. Hepatitis C virus infection is associated with a variety of extrahepatic manifestations including autoimmune features like cryoglobulinemia, Sjögren's syndrome, and autoimmune hepatitis. Here we report the case of a 42-year-old man with aplastic anemia due to posttransfusional hepatitis C virus infection associated with cryoglobulinemia and LKM-1 autoantibodies. Following a triple immunosuppressive therapy, there was a complete reconstitution of the bone marrow. Serum HCV-RNA as well as plus- and minus-stranded HCV-RNA in peripheral blood mononuclear cells (PBMC) were detected before immunosuppressive therapy. After therapy, serum HCV-RNA persisted. Furthermore, PBMC now were positive for plus-stranded RNA only. However, in bone marrow-derived precursor cells we failed to demonstrate HCV molecules after therapy. This would argue for reconstituted PBMC from newly generated uninfected precursor cells. It remains unclear as to whether the autoimmune character of the disease or the hepatitis C virus infection itself have contributed to the pathogenesis of the aplastic anemia.

Parosteal osteosarcoma of the talus

A case of parosteal osteosarcoma in the very rare location of the talus is presented. The radiological, pathological, and clinical characteristics of parosteal osteosarcoma are described and the differential diagnosis discussed.

Complement components C1q, C1r/C1s, and C1INH in rheumatoid arthritis. Correlation of in situ hybridization and northern blot results with function and protein concentration in synovium and primary cell cultures

OBJECTIVE

To analyze the synovial site and the cell types expressing C1q, C1r/C1s, and C1-esterase inhibitor (C1INH) and to characterize newly synthesized C1q in patients with rheumatoid arthritis (RA).

METHODS

Tissue and primary cell cultures of synovium from RA patients were analyzed for C1q, C1r/C1s, and C1INH by Northern blotting, in situ hybridization, and pulse-chase experiments for C1q.

RESULTS

The de novo synthesis of C1q, C1r/C1s, and C1INH in synovium and primary cell cultures was proven by Northern blot and by antigenic and functional analysis. In in situ hybridization experiments, the synovial lining cell layer was identified as the site of C1q, C1r, and C1INH expression. In contrast, immunohistologic analysis showed that C1q, C1s, and C1INH proteins were present in a thin film covering the synovial lining cells. In situ hybridization performed on primary cell cultures provided evidence that only macrophages were able to express C1q, whereas fibroblasts and stellate cells synthesized C1r.

CONCLUSION

The synovium is important for the synthesis and secretion of C1q and C1r/C1s, as well as the control protein C1INH, which supports the idea of a locally occurring inflammatory process in RA patients.

Establishment and characterization of two divergent cell lines derived from a human chromophobe renal cell carcinoma

The chromophobe renal cell carcinoma is a distinct type of renal cancer presumably derived from the intercalated cell of the collecting duct system and exhibiting a better prognosis than other types of renal cell carcinoma. Chromophobe carcinomas can be separated from other types of renal cell carcinoma by their characteristic cytomorphology, ultrastructural appearance, cytoskeletal architecture, and cytogenetic aberrations. As no permanent cell line of the chromophobe tumor type has previously been described, we are the first to report on the successful establishment and characterization of two divergent permanent cell lines, ie, chrompho-A and chrompho-B, derived from the same chromophobe renal cell carcinoma. With immunocytochemistry, two-dimensional gel electrophoresis, and Western blot, chrompho-A and chrompho-B exclusively exhibited cytokeratins (Nos. 7, 8, 18, and 19) but not vimentin. Ultrastructural studies revealed numerous cytoplasmic microvesicles as well as coated vesicles that are known to be characteristic features of the intercalated cell. Chrompho-B cells exhibited a shorter mean population doubling time (tD = 43 hours) than chrompho-A cells (tD = 51 hours). Both cell lines failed to produce tumors in nude mice with the subrenal capsule assay. Cytogenetic analyses revealed hyperdiploid chromosome numbers in both cell lines with telomeric associations as well as numeric aberrations known from chromophobe renal cell carcinomas in vivo.

Chromosomal changes in renal oncocytomas. Evidence that t(5;11)(q35;q13) may characterize a second subgroup of oncocytomas

Many of the reported oncocytomas have different chromosome abnormalities, indicating that they comprise a cytogenetically heterogenous group of tumors consisting of potentially cytogenetic subgroups. We have performed cytogenetic studies on nine renal oncocytomas. Clonal abnormalities were present in eight tumors. The findings most observed were the loss of the Y chromosome, and abnormalities of chromosomes 1 and 22. We also observed telomeric associations (tas) in two tumors and structural aberrations of chromosomes 9p and 19q, as well as monosomy 10. In two cases we found a similar reciprocal t(5;11)(q35;q13) in two cases. Review of the literature disclosed one other oncocytoma with a t(5;11) (q35;q13). This suggests that t(5;11)(q35;q13) defines a (second) subset of oncocytomas apart from the subgroup specifically associated with the loss of chromosomes 1 and Y.

Maximum androgen deprivation prior to radical retropubic prostatectomy in patients with stage T3 adenocarcinoma of the prostate

Eighty-two patients with stage T3 carcinoma of the prostate were treated for 3 months prior to radical retropubic prostatectomy with a luteinizing-hormone-releasing hormone analogue and an antiandrogen. Based on digital rectal examination (DRE), reduction of prostate and tumor size was noted in all cases. Ultrasound demonstrated a decrease in prostatic volume between 0 and 62.5% (median 32%). Prostate-specific antigen levels (PSA, Hybritech) decreased substantially (mean PSA of 29.5 ng/ml before to a mean PSA of 1.3 ng/ml after hormonal treatment). Pathologically, only 15 patients (18.3%) had organ-confined disease (stage pT2), 44 (53.7%) had stage pT3 tumors and 22 (26.8%) had positive lymph nodes. In 1 surgical specimen (1.2%), no residual tumor was identified. In 5 patients with nodal metastasis and 13 patients with seminal vesicle invasion, PSA levels after pretreatment were below 0.5 ng/ml. Compared to the preoperative needle biopsy, a decrease in the histological grade was found in only 7 tumors, while an increase was noted in 26. DRE, ultrasound and PSA suggest a downstaging of stage T3 prostate cancer after 3 months of maximum androgen deprivation. This cannot be confirmed pathologically. Prospective studies with this treatment regimen should concentrate on a possible benefit concerning local and distant cancer control and survival.

Cellular immune response to human renal-cell carcinomas: definition of a common antigen recognized by HLA-A2-restricted cytotoxic T-lymphocyte (CTL) clones

Cytotoxic T lymphocyte (CTL) clones directed against autologous renal-cell carcinoma (RCC) cell lines were generated by mixed lymphocyte/tumor-cell culture (MLTC) using peripheral blood lymphocytes (PBL). A CD8+, CD4- CTL clone MZ1257-CTL 5/30 with high cytolytic activity for the autologous tumor cell line MZ1257-RCC was established. No lysis of the autologous EBV-transformed B lymphocytes (EBV-B) or K562 cells was observed. A panel of HLA-A2-matched allogeneic RCC lines was recognized by CTL 5/30. Further specificity analysis showed a cross-reactivity with HLA-A2-matched allogeneic tumor cells of various origins, especially melanoma. CTL 5/30 was also cross-reactive with several HLA-A2-positive allogeneic normal kidney cells in culture. The restriction element identified for CTL 5/30 was HLA-A2, as shown by blocking of cytotoxicity using an anti-HLA-A2 monoclonal antibody (MAb) and by resistance of an HLA-A2-negative melanoma variant SK29-MEL. 1.22 against lysis by CTL 5/30. In this report we demonstrate HLA-A2-restricted recognition of a T-cell-defined antigen on autologous renal-cancer cells. This antigen is also expressed and recognized in association with HLA-A2 on normal kidney cells in culture and other HLA-A2-positive tumor cells. It may therefore be a normal differentiation antigen to which tolerance is incomplete in the renal-cell cancer system investigated.

[Comparison of the value of angioscopy, angiography and ultrasonography in detection of pathologic vascular processes]

AIMS

The ability of angioscopy, angiography and sonography to evaluate arteriosclerotic vascular lesions were compared to determine if angioscopy is a valuable addition in the diagnostic armamentarium.

METHODS

An in-vitro study was selected to enable microscopic assessment of the arteries. Angiography was followed by sonography and endoscopy and finally the vessels were evaluated macro- and microscopically.

RESULTS

The configuration of the vascular stenosis (plaque-shape, semicircular-eccentric, circular-concentric) was more reliably defined with angioscopy as compared to angiography and sonography. Intense calcification of plaque was detected sonographically with a high sensitivity (90%) using the acoustic shadowing and high amplitude criteria. Angioscopy was superior in differentiating between simple and complicated plaques and the assessment of ulcerations, while the visualization of the entire vascular tree with potential collaterals remained the domain of angiography.

CONCLUSIONS

Angioscopy seems to be valuable addition in the evaluation of arterial vascular disease. It can be used in the quality control after interventional radiology and surgery.

Multifocal renal cell tumors: a retrospective analysis of 56 patients treated with radical nephrectomy

In this retrospective analysis of 56 patients with multifocal renal cell tumors the effect of secondary tumors on the prognosis was examined and the incidence of tumors in the contralateral kidney was evaluated. All of the primary tumors were renal cell carcinomas, the majority of which had a local tumor stage of pT2 (31 cases, 55.3%) and a cytological grading of 1 (23 cases, 41%). The mean size of the secondary tumors was 1.0 cm. An additional tumor was diagnosed in 23 patients (41%), 2 to 5 secondary tumors in 23 (41%) and more than 5 additional tumors in 10 (18%). The overall 5-year survival rates were 69.4%, 72.2% and 40%, respectively (p = 0.313). Histopathological differentiation of the additional lesions revealed 23.2% renal cell carcinomas, 71.4% adenomas and 5.3% renal tumors of "doubtful dignity," with overall 5-year survival rates of 67.2% for adenomas, and 60.6% for carcinomas and renal tumors of "doubtful dignity" (p = 0.546). After a mean followup of 60 months 33 patients (58.9%) were alive without evidence of disease, 1 (1.7%) was alive with tumor progression, 8 (14.2%) died of the disease and 14 (25%) died of other causes; only 1 patient presented with a tumor in the contralateral kidney (incidence 1.7%). Thus, the overall 5-year survival rate for the entire group was 66.0% and the histopathological parameters of the additional tumors had no effect on the prognosis of the patients.

Specific loss of chromosomes 1, 2, 6, 10, 13, 17, and 21 in chromophobe renal cell carcinomas revealed by comparative genomic hybridization

We analyzed 19 chromophobe renal cell carcinomas by means of comparative genomic hybridization. Two tumors revealed no numerical abnormalities. In the remaining 17 cases we found loss of entire chromosomes with underrepresentation of chromosome 1 occurring in all 17 cases; loss of chromosomes 2, 10, and 13 in 16 cases; loss of chromosomes 6 and 21 in 15 tumors; and loss of chromosome 17 in 13 cases. The loss of the Y chromosome was observed in 6 of 13 tumors from male patients, whereas 1 X chromosome was lost in 3 of 4 tumors obtained from females. Comparative genomic hybridization results were verified by interphase cytogenetics. We conclude that a specific combination of multiple chromosomal losses characterizes chromophobe renal cell carcinomas and may help to differentiate them unequivocally from other types of kidney cancer.

[Bone remodeling after reamed and unreamed intramedullary nailing. A histomorphometric study]

Experimental findings after unreamed nailing have indicated certain advantages for new bone formation in comparison to reamed nailing. It would be of interest to establish whether any essential differences can be determined in the extent and course of callus formation. To investigate this question, thin sections of bone from 16 tibiae (nailing after transverse osteotomy in sheep) were examined histomorphometrically the progress at the periosteal and interfragmentary surfaces of the remodelling callus being recorded separately after 4, 6 and 8 weeks. After unreamed nailing, more extensive and earlier formation of interfragmentary callus was observed. At 4 weeks postoperatively the remodelled periosteal bone surface was 158 mm2, which was 1.6 times that after the unreamed procedure (95 mm2). By 4 weeks after unreamed nailing the periosteal callus surface was already greater than 6 weeks after reamed nailing. On the basis of these experimental results the use of unreamed nailing can be recommended, especially for open fractures and fractures with severe soft tissue damage.

Immunocytochemical detection of P-glycoprotein: initial expression correlates with survival in renal cell carcinoma patients

We evaluated 28 patients with advanced renal cell carcinoma for the initial expression of P-glycoprotein (MDR1 gene product) employing immunocytochemistry. Tumor specimens were obtained upon primary tumor nephrectomy. In all patients, progression-free survival time following nephrectomy was evaluated and correlated statistically with the staining results. Progression-free survival of patients with no or very few (< 1%) P-glycoprotein-positive tumor cells (n = 8, median survival 27.0 months) was significantly extended (p < 0.04) as compared to patients with 1% or more P-glycoprotein-positive tumor cells (n = 20, median survival 4.0 months). Correlations with histopathological tumor characteristics were insignificant. These results suggest a potential role for P-glycoprotein as a biologic parameter predictive of tumor progression in renal cell carcinoma patients.

Detection of hepatitis C virus replication in ovarian metastases of a patient with hepatocellular carcinoma

Hepatocellular carcinoma is one of the most common human cancers with an annual incidence of about 1,000,000 cases worldwide. Although hepatocellular carcinoma is predominant in hepatitis B virus endemic areas, it has also become a major problem in Europe, Japan and North America in close association with the increasing incidence of hepatitis C virus infection. The pathogenetic role of hepatitis C virus infection in the development of HBsAg-negative hepatocellular carcinoma needs to be clarified. In this paper the case of a 66-year-old HBsAg-negative and anti-HCV positive female who developed hepatocellular carcinoma in a cirrhotic liver is reported. After 1 year of follow up, urgent laparotomy had to be performed due to highly differentiated ovarian metastases of the hepatocellular carcinoma. Plus- and minus-stranded HCV-RNA was detected by reverse transcription and "nested" polymerase chain reaction in both the patient's serum and in the metastatic ovarian tissue.