Somatic von hippel-lindau mutation in clear cell papillary cystadenoma of the epididymis

Papillary cystadenoma of the epididymis is an uncommon benign lesion that may occur sporadically or as a manifestation of von Hippel—Lindau (VHL) disease. Neither immunohistochemical studies nor molecular genetic analyses of the VHL gene have been reported previously for this lesion. The authors describe two cases of clear cell papillary cystadenoma of the epididymis, both of which were initially confused with metastatic renal cell carcinoma. Both lesions showed positive immunohistochemical staining for low and intermediate molecular weight keratins (Cam 5.2 and AE1/AE3), EMA, vimentin, α₁-antitrypsin, and α₁-antichymotrypsin. Each was negative for CEA. Because clear cell papillary cystadenoma is similar to renal cell carcinoma histologically, and because both occur as components of the von Hippel—Lindau disease complex, the authors analyzed both cases for the presence of mutations in the VHL gene. A somatic VHL gene mutation was detected in one of the two tumors by polymerase chain reaction followed by single-strand conformation polymorphism analysis. Direct sequencing revealed a cytosine to thymine transition at nucleotide 694, resulting in the replacement of an arginine with a stop codon after the sixth amino acid of exon 3. As the VHL gene is believed to function as a tumor suppressor gene, VHL gene mutations may play a role in the initiation of tumorigenesis in sporadic cystadenomas of the epididymis.     

Family history of von Hippel-Lindau disease was uncommon in Chinese patients: suggesting the higher frequency of de novo mutations in VHL gene in these patients

Von Hippel-Lindau (VHL) disease is an autosomal dominant familial cancer syndrome caused by germline mutations in VHL tumor suppressor gene. It is characterized by hemangioblastoma in central nervous system and retina, renal cell carcinoma or cyst, pheochromocytoma, pancreatic cyst and tumor, endolymphatic-sac tumor, and papillary cystadenoma in epididymis and broad ligament. Here, we used PCR-direct sequencing and universal primer quantitative fluorescent multiplex PCR (UPQFM-PCR) to detect VHL mutations in 16 patients clinically diagnosed with VHL disease. PCR-direct sequencing detected 12 germline mutations (75%, 12/16), in which a novel mutation of c.451A>T/p.Ile151Phe found in one proband had not been reported previously. UPQFM-PCR found two large deletions (12.5%, 2/16). The two remaining patients carried non-typical disease-causing mutations, including one silent mutation (c.481C>A/p.Arg161Arg) and one mutation in 3'-UTR (c.642+70C>A). Remarkably, 56.3% (9/16) probands did not have family history of VHL disease, suggesting the higher frequency of de novo mutations in Chinese patients. We also summarized Chinese VHL disease patients with VHL mutation findings published in the literature to provide information about the spectrum of VHL mutations in Chinese VHL disease patients.     

Papillary cystadenoma of the epididymis. Case report and review of the literature

The only known benign epithelial tumor of the epididymis is papillary cystadenoma. Since 1921, only 39 such tumors have been published. We report on a papillary cystadenoma in a 30-year-old patient. The tumor measures 1.5 cm and is located in the head of the left epididymis. Histomorphologically, these tumors are characterized by cysts with colloid-like contents and papillary formations of light epithelium. Papillary cystadenoma can occur uni- or bilaterally, most frequently in the head of the epididymis. Age of patients ranges between 16 and 81 years with 36.6 years on average. Bilateral papillary cystadenomas are combined in 65, unilateral in 18% with Hippel-Lindau' disease. Most authors regard ductuli efferents as point of origin of these rare benign tumors.     

Allelic deletion and mutation of the von Hippel-Lindau (VHL) tumor suppressor gene in pancreatic microcystic adenomas.

An association between pancreatic microcystic (serous) adenomas (MCAs) and von Hippel-Lindau (VHL) disease has been suggested. However, genetic alterations of the VHL gene in MCAs of the pancreas have never been reported. In this study, we performed genetic analysis of 12 pancreatic MCAs. In 2 cases, VHL disease was documented clinically, and 10 cases were sporadic. For LOH analysis, tumor and normal pancreatic cells were procured from formalin-fixed, paraffin-embedded material using tissue microdissection. After DNA extraction, the samples were amplified by polymerase chain reaction using the polymorphic markers D3S2452, D3S1110, D3S192, and D3S656. In addition, the sporadic tumors were analyzed for VHL gene mutations using probes 3b/10b and K55/K56. Both MCAs associated with VHL disease showed LOH with at least one of the microsatellite markers tested. Among the 10 sporadic cases, 7 tumors showed LOH at the VHL gene locus. A somatic VHL gene mutation on exon 2 was documented in one sporadic case. The study provides the first direct genetic evidence for the role of the VHL gene in MCA tumorigenesis. Furthermore, VHL gene alterations may be detected in both VHL-associated and sporadic pancreatic MCAs.     

Epididymal cystadenomas and epithelial tumourlets: effects of VHL deficiency on the human epididymis

Although epididymal cystadenomas (ECAs) are among the most frequent VHL disease-associated tumours, fundamental questions about their pathogenesis have remained unanswered. Classification of ECAs is controversial, and the cell of origin is unknown. It is also unknown whether ECAs-like other VHL disease-associated tumours-arise as a result of VHL gene inactivation, and whether ECAs exhibit subsequent activation of hypoxia-inducible factor HIF. Moreover, the morphological spectrum of earliest ECA formation is unknown. In a detailed molecular pathological analysis of a series of epididymides collected from VHL patients at autopsy, we found that ECAs are true neoplasms that arise secondary to inactivation of the wild-type copy of the VHL gene, followed by early and simultaneous activation of HIF1 and HIF2 associated with up-regulation of downstream targets, including CAIX and GLUT-1. The observations also indicate that ECA formation evolves from a variety of microscopic epithelial tumourlets, and that these tumourlets are confined to the efferent ductular system. Although genetic and immunohistochemical analysis of precursor structures consistently revealed VHL gene inactivation and activation of HIF in the precursor lesions, only a small subset appears to progress into frank cystadenoma. Thus, ECA tumorigenesis in VHL disease shares fundamental principles with tumorigenesis in other affected organ systems.     

Expression of fibronectin and HIF-1alpha in renal cell carcinomas: relationship to von Hippel-Lindau gene inactivation

The von Hippel-Lindau (VHL) tumor suppressor gene (TSG) at 3p25 is mutated in approximately 50% of conventional (clear cell) renal cell carcinomas (cRCC). VHL normally regulates the ubiquitin-mediated proteolysis of hypoxia-inducible factor 1alpha (HIF-1alpha), and VHL inactivation results in increased cellular HIF-1alpha expression. VHL protein (pVHL) also interacts with fibronectin (Fn) and VHL inactivation results in defective Fn extracellular matrix assembly. The present study investigated the immunohistochemical (IHC) staining for Fn and HIF-1alpha in 11 cRCC and the relationship of the staining to VHL inactivation by gene deletion, mutation, or hypermethylation. Evidence for VHL inactivation by 3p deletions and VHL mutations were found in six tumors. Fn-positive IHC staining of tumor cells and negative to weak staining of extracellular stroma was found in five cases having exon 1 or exon 2 mutations. In contrast, Fn staining was absent in tumor cells and positive in the stroma of five tumors without VHL inactivation and in one tumor with a C-terminal exon 3 mutation. HIF-1alpha tumor cell staining was present in the cRCC with VHL inactivation but was also present in two tumors having 3p deletions but neither mutation nor hypermethylation of VHL. These two cRCC showed a tumor cell-negative and stroma-positive pattern of Fn staining. The findings indicate that VHL inactivation plays a role in the development of some cRCC by altering Fn cell--stroma relationships. They also suggest that some C-terminal mutations may not interfere with Fn assembly and that a 3p TSG in addition to VHL influences HIF-1alpha degradation.     

The isolation of a yeast artificial chromosome (YAC) contig extending for 2 megabases in the vicinity of the Von Hippel Lindau disease gene

Von Hippel LIndau disease (VHL) is a rare autosomal dominantdisease associated with tumors and cysts in multiple organ systems.The VHL disease gene is tightly linked to the polymorphic DNAmarker 233E2 (D3S720) and flanked by 479H4 (D3S719) on its telomericand RAF1 on its centromeric side. Two additional markers, D3S1038and D3S601, have also been identified, and these markers, likeD3S720, are very tightly linked to VHL. Previously 93 cosmidclones were mapped to the larger region, 3p24.2 - pter, surroundingthe VHL disease gene (1). Using a Southern-based screening strategyon pools of YAC clones we have Isolated a contig of overlappingYAC clones that extends about 0.7 megabase centromeric, andabout 1.3 megabases telomeric of D3S720 and contains all threetightly linked VHL markers. Individual YACs In this contig werehybridized to grids containing cosmids localized between 3p24.2-pterand to several cosmids localized by fluorescent in situ hybridization(FISH) to 3p25. A total of 28 cosmids were positioned on thiscontig of overlapping YAC clones. We have also identified homologousYAC clones to many additional cosmid clones localized between3p24.2–p25, although these have not yet been preciselylocalized relative to the contig of YAC clones. This contigof YAC clones probably contains the VHL disease gene and shouldfacilitate the isolation and characterization of this gene.     

Microsatellite instability in intraductal papillary neoplasms of the biliary tract.

Intraductal papillary neoplasms of the biliary tree are unusual lesions characterized by solitary or diffuse growth along the intra- and/or extrahepatic biliary tract. Biliary papillary neoplasms bear some clinicopathologic similarity to intraductal papillary mucinous neoplasms of the pancreas. Like intraductal papillary mucinous neoplasms of the pancreas, biliary papillary neoplasms can be purely intraductal lesions or can give rise to invasive adenocarcinomas. We recently studied the genetic alterations present in a series of biliary papillary neoplasms and noted the presence of allelic shifts in some biliary tumors during allelic loss assays on chromosomes 5q and 18q. This suggested that microsatellite instability might play a role in the molecular pathogenesis of biliary papillary neoplasms. Genomic DNA was extracted from 17 intraductal papillary neoplasms, 6 associated invasive cholangiocarcinomas, and corresponding normal tissues, and microsatellite instability testing was performed using the 5 microsatellite loci recommended by the 1997 National Cancer Institute-sponsored consensus conference (D2S123, D5S346, D17S250, Bat-25, and Bat-26). High-level microsatellite instability was considered to be present when at least two of five microsatellite loci showed allelic shifts, and low-level microsatellite instability, when only one locus was shifted, as per the National Cancer Institute criteria. We also determined the methylation status of the DNA mismatch repair gene hMLH1 by bisulfite treatment of genomic DNA, followed by methylation-specific PCR. High-level microsatellite instability was present in 2 of 17 (11.8%) biliary papillary neoplasms, including 1 case of purely intraductal tumor and 1 case with both intraductal and invasive cholangiocarcinoma components. In both cases there was extensive microsatellite instability, with allelic shifts in five of five and four of five microsatellite markers, respectively. Low-level microsatellite instability was present in 6 of 17 (35.3%) biliary papillary neoplasms, including 2 cases of purely intraductal tumor and 4 cases with both intraductal and invasive cholangiocarcinoma components. Interestingly, the pattern of allelic shifts was frequently not identical between the intraductal and invasive cholangiocarcinoma components; although the same microsatellite markers were shifted, alleles of differing lengths were generated in the intraductal and invasive components of the neoplasms with high-level microsatellite instability and of two neoplasms with low-level microsatellite instability. None of the biliary papillary neoplasms (0 of 10 cases with adequate DNA for evaluation) showed methylation of hMLH1. These results indicate that microsatellite instability is a relatively frequent event in papillary neoplasms of the biliary tree but is not associated with hMLH1 promoter hypermethylation. The finding that alleles of differing lengths were frequently generated between the intraductal and invasive components of those tumors with microsatellite instability suggests that there is significant genetic heterogeneity within these neoplasms.     

An analysis of five clear cell papillary cystadenomas of mesosalpinx and broad ligament: four associated with von Hippel-Lindau disease and one aggressive sporadic type

Nogales F F, Goyenaga P, Preda O, Nicolae A, Vieites B, Ruiz‐Marcellan M C, Pedrosa A & Merino M J
(2012) Histopathology  60, 748–757
An analysis of five clear cell papillary cystadenomas of mesosalpinx and broad ligament: four associated with von Hippel‐Lindau disease and one aggressive sporadic type Aims: Clear cell papillary cystadenoma (CCPC) is associated with von Hippel‐Lindau disease (VHLD), but rarely involves mesosalpinx and broad ligament (M/BL). This study provides new data about its behaviour and immunophenotype. Methods and results: We performed an analysis of four benign cases of CCPC of M/BL with either characteristic clinical features or genetic markers [loss of heterozygosity (LOH)] of VHLD in patients ranging from 24 to 36 years and a sporadic case in a 52‐year‐old presenting with peritoneal metastases. All CCPCs were papillary but had solid and tubular areas. Haemorrhage, thrombosis and scarring were constant features and related to an unusual pattern of sub‐epithelial vascularity. All clear or oxyphilic cells co‐expressed cytokeratin 7 (CK7), CAM5.2 and vimentin, with strong apical CD10 and nuclear paired box gene 2 (PAX2) immunoreactivity. Three cases also showed positivity for VHL40, epithelial membrane antigen (EMA), Wilms’ tumour suppressor gene (WT‐1) and cancer antigen 125 (CA125) but only one expressed renal cell carcinoma (RCC) antigen. Vascular plexus overexpressed nuclear and cytoplasmic WT‐1. Conclusion: The VHLD‐associated cases appeared to be benign, but the sporadic case exhibited a low malignant potential. CCPCs show histological and immunophenotypical similarities with the recently reported clear cell papillary RCC, although the previously unreported apical CD10 and nuclear PAX2 expression may be related to their mesonephric origin. CCPC has a distinctive sub‐epithelial vascular pattern that is consistent with its pathogenesis.     

Papillary cystadenoma of the epididymis. A report of three cases with lectin histochemistry.

Papillary cystadenoma of the epididymis is an uncommon benign tumor associated with von Hippel-Lindau disease. Since metastatic renal cell carcinoma may be histologically similar to papillary cystadenoma, and both are associated with von Hippel-Lindau disease, differentiation between these two entities may be difficult. We performed lectin histochemistry studies on three papillary cystadenomas and compared the results with the staining observed in epididymal ducts, epididymal efferent ductules, and three renal cell carcinomas. Common positive staining was observed following incubation with soybean agglutinin in epididymal ducts and two of the three papillary cystadenomas, while the three renal cell carcinomas did not stain. When epididymal tumors histologically consistent with papillary cystadenoma fail to react with soybean agglutinin, thorough clinical evaluation for an occult renal cell carcinoma should be performed.     

Cysts and epithelial proliferations of the testicular collecting system (including rete testis)

Neoplastic and non-neoplastic proliferations of the testicular collecting system may be a source of diagnostic difficulty as they are rarely encountered and may have an appearance that leads to confusion with lesions arising in adjacent structures. The rete testis and epididymis are the 2 sites that are most likely to give rise to this unusual group of lesions. This article principally, although not exclusively, deals with those lesions that produce an intrascrotal mass. These include benign acquired or developmental cysts such as cystic dysgenesis of the rete testis or acquired cystic transformation of the rete testis, non-neoplastic epithelial proliferations such as adenomatous hyperplasia of the rete testis or cribriform hyperplasia of the epididymis, and benign or malignant neoplasms. Rete testis cystadenoma, including the sertoliform variant, and papillary cystadenoma of the epididymis are examples of benign tumors of the testicular collecting system that must be considered, the latter is the more likely of the 2 to be encountered. Primary carcinoma of either the rete testis or the epididymis is a rare occurrence; these entities are considered in some detail to allow for their recognition and distinction from other tumors that may occur in this region. Our own experience with 18 unpublished cases of lesions of the rete is also present.     

Detailed genetic mapping of the von Hippel-Lindau disease tumour suppressor gene.

Von Hippel-Lindau (VHL) disease is an autosomal dominant inherited familial cancer syndrome characterised by a predisposition to the development of retinal, cerebellar, and spinal haemangioblastomas, renal cell carcinoma, and phaeochromocytoma. The gene for VHL disease has been mapped to chromosome 3p25-p26 and flanking markers identified. We report the detailed genetic mapping of the VHL disease locus in 38 families. Significant linkage was detected between VHL disease and D3S601 (Zmax = 18.86 at theta = 0.0, CI 0.0-0.025), D3S18 (Zmax = 11.42 at theta = 0.03, CI 0.005-0.08), RAF1 (Zmax = 11.02 at theta = 0.04, CI 0.007-0.01), and D3S1250 (Zmax = 4.73 at theta = 0.05, CI 0.005-0.15). Multipoint linkage analysis mapped the VHL disease locus between D3S1250 and D3S18 close to D3S601. There was no evidence of locus heterogeneity. This study has (1) confirmed the tight linkage between VHL disease and D3S601, (2) identified D3S1250 as the first marker telomeric to RAF1 which maps centromeric to the VHL disease gene, and (3) narrowed the target region for isolation of the VHL disease gene by positional cloning techniques to a 4 cM interval between D3S1250 and D3S18. These findings will improve the clinical management of families with VHL disease by improving the accuracy of presymptomatic diagnosis using linked DNA markers, and will enhance progress towards isolating the VHL disease gene.     

青少年肾细胞癌的临床病理及分子遗传学研究

目的 探讨青少年肾细胞癌的临床病理特征、遗传学改变、鉴别诊断及预后.方法 对46例青少年肾细胞癌进行光镜观察及免疫组织化学染色,随访并复习相关文献.对46例肿瘤进行von Hippel-Lindau(VHL)基因区域杂合性缺失(LOH)及VHL基因突变筛查.结果 共诊断19例Xp11.2易位/TFE3基因融合相关性肾癌(Xp11 RCC)、9例透明细胞癌、17例乳头状肾细胞癌(PRCC)和1例不能分类肾细胞癌.19例Xp11 RCC均TFE3阳性,而TFEB阴性.8例肿瘤具有巢状和乳头状结构形态类似t(X;17)ASPL-TFE3型肾癌,6例肿瘤组织学类似t(X;1)PRCC-TFE3型肾癌,4例肿瘤形态像透明细胞癌,1例肿瘤组织学形态文献中未被检索到,表现为细胞核呈毛玻璃样,核仁不明显,可见核沟,肿瘤间质见大量黏液.LOH及VHL突变检测结果显示,仅1例透明细胞癌和1例2型PRCC存在LOH,并且该2型PRCC的VHL基因的一个剪切位点存在胚系突变,553+5 G→C.其余45例均未检测出VHL突变.统计学分析表明TFE3阳性肾细胞癌比TFE3阴性肾细胞癌更倾向于高病理分期(pT3/pT4),并且预后较差(P=0.035).结论 青少年肾细胞癌表现出不同的组织学形态以及分子遗传学背景.其中Xp11 RCC为最常见的肾癌亚型.TFE3阳性肾细胞癌的预后要差于TFE3阴性肾细胞癌.     

Expression of HIF-1 and ubiquitin in conventional renal cell carcinoma: relationship to mutations of the von Hippel-Lindau tumor suppressor gene

Conventional clear cell renal cell carcinomas (cRCC) have mutations of the von Hippel-Lindau (VHL) tumor suppressor gene at 3p25 in approximately 50% of cases. The VHL gene normally regulates ubiquitin-mediated proteolysis of hypoxia-inducible factor 1alpha (HIF-1alpha); in cell lines, VHL inactivation blocks HIF-1alpha proteolysis, resulting in increased HIF-1 expression. This study was undertaken to investigate the relationship between VHL mutations and the expression of ubiquitin and HIF-1alpha in cRCC. Eleven cRCC were studied with microsatellite analysis for 3p deletions and with sequencing for VHL mutations. Immunohistochemistry was performed for HIF-1alpha and ubiquitin. Deletions at 3p25 were found in 10 tumors, and VHL mutations were identified in 6 of these cases. There was staining for ubiquitin and HIF-1alpha in all tumors with VHL mutations. Among the five cases without VHL mutations, staining for ubiquitin or HIF-1alpha was not present in three cases but was present in two tumors, both of which had 3p deletions. The findings support a role for VHL mutations promoting cRCC development by an impairment of HIF-1alpha proteolysis. The findings also suggest that a 3p tumor suppressor gene other than VHL may also influence HIF-1alpha degradation and that there is an additional tumorigenic pathway for cRCC that does not involve VHL or HIF-1.     

Somatic von Hippel-Lindau disease gene mutation in clear-cell renal carcinomas associated with end-stage renal disease/acquired cystic disease of the kidney

It has been documented that renal cell carcinomas (RCCs) occur frequently in patients treated with long-term dialysis, especially in cases of end-stage renal disease (ESRD)/acquired cystic disease of the kidney (ACDK). To address the molecular pathogenesis of ESRD/ACDK-associated RCCs, we examined 14 RCCs (7 clear-cell and 7 papillary carcinomas) in patients receiving dialysis for somatic mutations of the von Hippel-Lindau disease (VHL) gene as well as of the tyrosine kinase domain of the MET oncogene. Direct sequencing analyses revealed that three tumors exhibited VHL frameshifts (618delA, 386-395del10-bp, and 723-724insTC). One of the VHL mutated tumors showed additional loss of heterozygosity at the VHL gene locus. Histopathologic and clinical data demonstrated that the three tumors having VHL mutations were clear-cell RCCs occurring in ESRD with 55, 106, and 156 months of dialysis history, respectively. We did not find any tumors with mutations in the tyrosine kinase domain of the MET. These results demonstrated that the VHL tumor-suppressor gene is also involved in a subset of clear-cell RCCs occurring in ESRD/ACDK, as in the case of sporadic clear-cell RCCs. However, mutations of the MET oncogene could not be found in the seven ESRD/ACDK-associated papillary RCCs examined.     

Clear cell papillary renal cell carcinoma and clear cell renal cell carcinoma arising in acquired cystic disease of the kidney: an immunohistochemical and genetic study

Clear cell papillary renal cell carcinoma (RCC) is a recently established disease entity. However, there are few reports on genetic study of this entity. We report such a case with focus on genetic study. A 57-year-old Japanese man was found to have 3 renal tumors. Histologically, two tumors showed findings of clear cell RCC; and the other tumor showed findings of clear cell papillary RCC that was characterized by papillary growth pattern of neoplastic cells in cystic space with purely clear cell cytology. Immunohistochemically, tumor cells of clear cell papillary RCC were diffusely positive for PAX2 and cytokeratin 7, but negative for CD10, RCC Ma, and AMACR. In fluorescence in situ hybridization study for one clear cell papillary RCC, we detected polysomy for chromosome 7 and monosomy for chromosomes 17, 16, and 20. In addition, we detected mutation of VHL gene in clear cell RCC, but found no VHL gene mutation in clear cell papillary RCC. Finally, our results provide further evidence that clear cell papillary RCC may be both morphologically and genetically distinct entity from clear cell RCC and papillary RCC.     

Genetic linkage between Von Hippel--Lindau disease and three microsatellite polymorphisms refines the localisation of the VHL locus

Von Hippel—Lindau (VHL) disease is a dominantly inheritedfamilial cancer syndrome characterised by the development ofretinal and central nervous system haemangioblastomas, renalcell carcinoma and phaeochromocytoma. The gene for VHL diseasehas been mapped to chromosome 3p25–p26 and presymtomaticdiagnosis using linked DNA markers is available. We have previouslymapped the VHL disease gene to a 4 cM interval between D3S1250and D3S18. To increase access to presymptomatic diagnosis andto accelerate progress towards isolating the VHL disease genewe attempted to identify microsatellite DNA markers linked tothe disease gene by genetic linkage analysis in 29 families.We found significant linkage between the VHL disease gene anddinucleotide (CA) repeat polymorphisms at D3S1038 (Zmax = 22.24at     

Role of disease-causing genes in sporadic pancreatic endocrine tumors: MEN1 and VHL

Pancreatic endocrine tumors (PETs) occur in association with multiple endocrine neoplasia type 1 (MEN1) and von Hippel-Lindau (VHL) syndromes caused by germline alterations in MEN1 and VHL, respectively. It is thus expected that these genes will also be altered in a proportion of sporadic PETs. Indeed, MEN1 is altered in about 25% of nonfamilial PETs, although no mutations have been found in VHL. For all clinical subtypes, the frequency of allelic loss on chromosome arm 11q mirrors observed mutational frequencies, with the exception of nonfunctional tumors (NF-PETs), in which mutations have been reported in only 8% of cases. As allelic loss on 11q is the most frequent event found in these neoplasms, this low frequency is somewhat puzzling, particularly in light of the fact that most MEN1-associated PETs are nonfunctioning. To clarify the role of these genes in sporadic PETs, we analyzed 31 sporadic NF-PETs, nine insulinomas, and one VIPoma for alterations in MEN1 and VHL. As somatic mutations were observed in eight (26%) of the NF tumors and in one insulinoma, it would therefore appear unlikely that an additional tumor suppressor gene related to sporadic PET pathogenesis is located on 11q. One insulinoma also had a somatic mutation in VHL, and thus this gene may also be altered in these neoplasms, albeit in a small proportion of cases.     

Estrogen-receptor protein in thyroid neoplasms. An immunohistochemical analysis of papillary carcinoma, follicular carcinoma, and follicular adenoma.

Epidemiologic features of well-differentiated thyroid tumors and experimental evidence suggest that female sex hormones may exert effects on this gland and its neoplasms. This possibility was addressed by investigating the expression of estrogen-receptor protein in 80 thyroid neoplasms. Patients with papillary carcinomas, follicular carcinomas, and follicular adenomas were selected from each of the following groups: (1) postpubertal-premenopausal women (who are associated with the most favorable prognosis and greatest incidence of these neoplasms); (2) postmenopausal women; and (3) men of various ages. Sections from formalin-fixed paraffin-embedded tumors were stained with antiestrophilin antibody (clone H222) and the avidin-biotin-peroxidase complex method. In addition, other markers were included to distinguish thyroidal from other estrogen-receptor protein-reactive neoplasms; an anticytokeratin mixture, antithyroglobulin, and anti-gross cystic disease fluid protein-15 were applied in all cases. The expression of estrogen-receptor protein was detected in eight of 10, six of 10, and nine of 10 papillary carcinomas; four of eight, two of seven, and one of five follicular carcinomas; and none of 10, none of 10, and two of 10 follicular adenomas, in groups 1, 2, and 3, respectively. Nuclear staining was regional or multifocal in distribution. Cytokeratin and thyroglobulin were detected in all tumors. In contrast, none displayed anti-gross cystic disease fluid protein-15 immunoreactivity. These results indicate that the estrogen receptor may be detected immunohistochemically in thyroid neoplasms. However, no differences that could account for possible estrogen-related epidemiologic and prognostic variation in such tumors could be ascertained. Other discriminating immunostains, primarily including anti-gross cystic disease fluid protein-15 and thyroglobulin, are effective in distinguishing between thyroidal and extrathyroidal tumors that may express estrogen-receptor protein.