The in vitro growth and characterization of the skeletal muscle component of Wilms'' tumor.

Skeletal muscle differentiation within a Wilms' tumor is a well-documented histopathologic entity thought to occur at a relatively low incidence and influence prognosis. A serum-free hormonally defined growth medium has been developed, allowing the long-term growth of the skeletal muscle component of Wilms' tumors. Eight Wilms' tumors have been grown under these conditions. Three cases grew a homogeneous population of cells which ultrastructurally displayed all stages of myogenesis through myotubule formation. They also possessed immunoreactivity for skeletal muscle myosin and myoglobin and synthesized the M and B subunits of creatine kinase. Of interest was the finding that the ability to yield skeletal muscle cultures was limited to those cases which exhibited skeletal muscle fibers in vivo. This technique is also a very sensitive marker for identifying Wilms' tumors possessing a myoid component. A second serum-free hormonally defined medium has also been developed that supports the long-term culture of a unique cell type from Wilms' tumors which contain a myoid component. These cells are spindle-shaped and exhibit all of the characteristics of early myoblasts.     

The in vitro growth, heterotransplantation, and differentiation of a human rhabdomyosarcoma cell line.

A human rhabdomyosarcoma (RMS) cell line was established from a case of childhood small cell sarcoma, which in vivo showed no evidence of differentiation, but which demonstrated myogenic differentiation in tissue culture. In a serum-free culture medium, the tumor cells demonstrated continuous growth without ultrastructural or biochemical evidence of differentiation. Heterotransplanted RMS cells gave rise to tumors in nude mice which also showed no myogenic differentiation. However, RMS cells grown in the presence of either retinoic acid (5 microns), phorbol ester (1 nM), prostaglandin E1 (10 ng/ml), or 2% fetal calf serum gave rise to myotubes with a biochemical shift in the creatine kinase isoenzyme pattern from the embryonic to the mature skeletal muscle form. The karyotype of the RMS cells revealed a translocation of Chromosomes 2 and 13, which may represent a nonrandom aberration unique to this morphologic subtype. In addition, the RMS cells gave evidence for gene amplification in the form of double minute chromosomes. This human RMS cell line provides a valuable in vitro system for study of myogenesis and factors which induce differentiation.     

Wilms' tumor, overgrowth, and fetal growth factors: a hypothesis

A hypothesis is advanced suggesting that the association between high birthweight, overgrowth features of certain congenital malformations, and Wilms' tumor may be due to the action of loci in addition to the putative Wilms' tumor locus on the short arm of chromosome #11. These genes include insulin, insulin-like growth factor II and the c-Ha-ras 1 oncogene. The possible role of environmental factors in the oncogenesis of Wilms' tumor is discussed.     

The cytogenetics of Wilms' tumor

A close association has been demonstrated between the congenital deletion 11p13 and predisposition to Wilms' tumor. Recent cytogenetic studies on Wilms' tumor cells from normal children strongly suggests that somatic changes in the short arm of chromosome #11 play an important role in the development of this tumor. The application of improved cytogenetic techniques coupled with molecular biologic analysis may help resolve questions regarding the requirement of additional changes (to alterations of 11p13) in order to evoke complete transformation leading to malignancy.     

Wilms' tumor of the endocervix

We report a case of primary Wilms' tumor of the endocervix in a 13-year-old girl. The tumor was polypoid, filled the vagina, and was attached to the endocervix by a stalk. Microscopic examination disclosed blastematous, epithelial, and stromal elements characteristic of Wilms' tumor. The patient's kidneys were normal on intravenous pyelographic examination and on palpation at laparotomy, and she has remained free of disease for 9.6 years after hysterectomy.     

Responsiveness of chemotherapy based on the histological type and Wilms' tumor suppressor gene mutation in bilateral Wilms' tumor

To clarify a characteristic of bilateral Wilms' tumor (WT), we examined the clinical and histological features, chemotherapy response and mutations in Wilms' tumor suppressor gene (WT1) in five patients. Deoxyribonucleic acid was extracted from peripheral lymphocytes and tumor samples, and direct DNA sequencing was performed to detect WT1 mutations. Paraffin sections were stained with H&E for histological review and immunostained with anti-WT1, anti-Ki-67, anti-S-100 protein and antimyogenin antibodies. In contrast to the single case of epithelial-type WT, the other four cases were fetal rhabdomyomatous nephroblastoma (FRN) or contained a premature skeletal muscle component and appeared to be resistant to chemotherapy because there was no reduction in tumor volume. However, after chemotherapy, most of the tumor components changed into mature striated muscle cells, most of which immunostained almost completely negative for Ki-67. All four cases had the same point mutation of WT1. From our results, the histological findings correlated with WT1 mutations in bilateral WT. The tumor volume of FRN did not decrease in response to chemotherapy. It is possible to predict the chemotherapy response by examining bilateral WT for WT1 mutations and the histological characteristics of tumors.     

Botryoid Wilms' tumor of the renal pelvis

We studied a unique example of Wilms' tumor consisting entirely of a polypoid intrapelvic renal mass. Despite a gross appearance akin to sarcoma botryoides, this and related examples of Wilms' tumor with intrapelvic growth should be treated no differently from ordinary Wilms' tumors of similar stage and grade.     

Morphologic and immunohistochemical characterization of Leydig cell tumor variants in Wistar rats.

During a routine long-term drug safety study, lasting approximately 2 1/2 yr, male Wistar rats, treated with a prolactin-inhibiting compound, developed an excess of Leydig cell tumors (LCTs). Most tumors were typical for the rat but a small number showed an unusual variation and some appeared malignant. The variation consisted of glandular and/or tubular structures within the tumor mass which occasionally anastomosed and contained an eosinophilic periodic-acid Schiff (PAS) positive material. In a few of these variants, malignant features such as cellular atypia, capsular, and lymphatic invasion and necrosis were seen. No metastases were detected. Detailed morphological and immunohistochemical investigations were conducted in order to establish the cell of origin of these variants. Glandular/tubular structures were found to stain with varying intensity for vimentin and cytokeratin, but were always negative for beta-tubulin. The results indicated that the cell of origin of these LCT variants was indeed the Leydig cell and that glandular and/or tubular structures within LCTs represented a form of Leydig cell metaplasia.     

Mixed epithelial and stromal tumor of the kidney: preliminary immunohistochemical and electron microscopic studies of the epithelial component

Mixed epithelial and stromal tumor of the kidney is a rare biphasic tumor composed of cysts and tubules embedded in the spindle cell stroma. Although the histogenesis of this tumor is unknown, it has been proposed that both components of the tumor, i.e., stromal and epithelial, are neoplastic. The authors report preliminary immunohistochemical and electron microscopic studies of the epithelial component from one case of a typical, benign, mixed epithelial, and stromal tumor of the kidney. In this study, some tubules showed positivity for proximal, while others showed positivity for distal, nephron immunomarkers. By electron microscopy, some tubules had features of proximal tubular epithelium, while other tubules had features of the loop of Henle (thin segments). The authors believe that in a benign tumor such morphologic heterogeneity is inconsistent with neoplastic proliferation. Therefore, they postulate that in mixed epithelial and stromal tumor of the kidney the tubules are entrapped rather than neoplastic. Additional studies are needed to address this issue and electron microscopy should play a significant role in this process.     

Abnormalities of chromosomes 1 and 11 in Wilms' tumor

Cytogenetic studies were performed successfully on 14 cases of Wilms' tumor. Six cases had detectable rearrangements of 11p, and 7 cases had structural abnormalities of chromosome #1. Two cases with advanced stage disease showed multiple translocations, resulting in hypodiploidy with a normal DNA complement.     

Anaplasia in unilateral Wilms' tumor: a report from the National Wilms' Tumor Study Pathology Center

Fifty-eight unilateral anaplastic Wilms' tumors entered on the Third National Wilms' Tumor Study (NWTS-3) were reviewed. The favorable outcome of stage I anaplastic tumors was confirmed. In stage II-IV tumors, the extent and severity of anaplasia were not of prognostic importance. However, two histologic features were correlated with extremely poor outcome; anaplasia in extrarenal tumor sites (P = .016) and predominantly blastemal tumor pattern (P = .020). The importance of these features in predicting relapse and death for children with anaplastic Wilms' tumor was supported by the study of 47 additional anaplastic Wilms' tumor cases from NWTS-2. These results emphasize the importance of examining sites of extrarenal spread in anaplastic Wilms' tumors. Cytologic criteria for anaplasia and clues to its recognition are reviewed, and the potential clinical and biological implications of our findings are discussed.     

Extracellular matrix and epithelial differentiation of Wilms' tumor

Different histologic types of 82 Wilms' tumors were graded on the basis of the histologic pattern. Representative tumors of each group were analyzed by the immunoperoxidase method for evaluation of the histogenesis of Wilms' tumor and the value of antibodies against extracellular matrix (ECM) components (collagens I and III, laminin, fibronectin) in differential diagnosis of different types of Wilms' tumors. The tubules of classic Wilms' tumor expressed laminin, which could be seen also in and around some blastemal cells. Blastema and tubules were negative for interstitial collagens, but Type I and III collagen were prominent in the fibrovascular stroma. The monomorphous tubular, psammomatous and rosetting tumors expressed laminin, but no interstitial collagens. In sarcomas, only the blastemal variant of spindle-cell sarcomas was negative for interstitial collagens, which were abundantly seen in all other sarcomas. While spindle-cell sarcomas were devoid of laminin, the highly malignant rhabdoid and clear-cell sarcomas expressed laminin in a characteristic dotted fashion. Staining for fibronectin gave varying results and had therefore only a limited value in distinguishing different types of Wilms' tumors. However, the antibodies against interstitial collagens and against the basement membrane glycoprotein laminin turned out to be a useful adjunct in differential diagnosis and classification, especially of sarcomatoid Wilms' tumors. The basement membrane of normal nephrons is similar to that in tubules of triphasic Wilms' tumor, but the ECM of blastemas is different. This transformed phenotype might represent a maturation arrest of the blastemal cell when compared with the expression of proteins during normal nephrogenesis.     

In vitro characterization and micromechanics of tumor cell chemotactic protrusion,locomotion, and extravasation

The objective of this paper is to introduce some novel in vitro applications in characterizing human melanoma cell protrusion and migration in response to soluble extracellular matrix protein stimulation. Specifically, we describe two assay systems: (1) dual-micropipette manipulation and (2) flow-migration chamber. Applications of the dual-micropipet technique provided kinetic measure of cell movement, cyclic pseudopod protrusion, and subsequent cell locomotion governed by chemotactic molecular transport dynamics. Chemotactic concentration gradient was found to influence significantly pseudopod protrusion frequency and locomotion speed, but not the protrusion extension. To further characterize active tumor cell extravasation, a process that involves dynamic tumor cell adhesion to vascular endothelium under flow conditions and subsequent transendothelial migration in response to chemotactic signals from the interstitial space, we developed a flow-migration chemotaxis system. This assay enabled characterization of tumor cell transcellular migration in terms of chemotactic signal gradients, shear forces, and cell-substrate adhesion. Results suggest that shear flow plays significant roles in tumor cell extravasation that is regulated by both tumor cell motility and tumor cell adhesion to endothelial molecules in a cooperative process. © 2002 Biomedical Engineering Society. PAC2002: 8717Jj, 8719Xx     

Fanconi's anemia, medulloblastoma, Wilms' tumor, horseshoe kidney, and gonadal dysgenesis

An 18-month-old female infant with clinically and cytogenetically documented Fanconi's anemia was found to have two neoplasms previously unreported in this syndrome to our knowledge: a medulloblastoma and a Wilms' tumor, with the latter arising in a horseshoe kidney. An additional feature was pure gonadal dysgenesis. These unusual associations are discussed in the context of certain syndromes suggestive of an axial predisposition for neoplasia (kidneys-central nervous system and kidneys-gonads).     

Analysis of Cox-2 expression in Wilms' tumor

Cylooxygenase-2 (Cox-2) inhibitors have increasingly become therapeutic alternatives in some Cox-2-overexpressing neoplasms. As the treatment eligibility for these drugs hinges on Cox-2 expression, Cox-2 immunostaining has recently been widely examined in several malignant neoplasms. However, data on the expression of Cox-2 in Wilms' tumor (WT) are limited. In this study, we examined Cox-2 expression in 40 examples of WT to identify the prognostic impact, to evaluate the effects on tumorigenesis, and to answer the question of whether neoplasms with Cox-2 expression could benefit from treatment with specific Cox-2 inhibitors. Sections from paraffin-embedded tumor samples were immunostained by a standard ABC technique using Cox-2 mouse monoclonal antibody. As in other rare examples reported in the literature, Cox-2 immunoreactivity was analyzed and correlated with histological features and the staging of neoplasms. However, in contrast to other studies, we also evaluated the relation of Cox-2 positivity to age, sex, and survival of patients. The results of this study demonstrated that Cox-2 was ubiquitously expressed in all cases of WT and their neovasculature, independently of the type of neoplasm (tumors with a favorable or unfavorable histology), tissues which constitute the neoplasm (blastemal, mesenchymal and epithelial, heterologous or non-heterologous elements), patient age, sex, or stage of development and survival rate. Thus, Cox-2 inhibitors could be used for treating all cases of WT. Further studies, including molecular investigations, would be useful to confirm our hypotheses.     

Wilms' tumor in adults: aspiration cytology and cytogenetics

The fine-needle aspiration cytologic findings of Wilms' tumor occurring in a 20-yr-old female patient and a 35-yr-old male patient showing blastemal, spindled sarcomatous and rare epithelial components are reported. The male patient had the typical presentation of renal mass with metastasis to lung and pleura, whereas the female patient had an unusual presentation with the tumor originated from the subcapsular nephrogenic zone of the kidney, extending into the liver without invasion into the renal cortex. Cytogenetic analysis of this case identified: 90, XXXX, +2x3-4, -5, -15, -16, -17, -17, i (17)(q10) x2. This finding may represent a genetic change associated with Wilms' tumor of older pediatric and young adult patients. To the best of our knowledge, this case is the sixth case with cytogenetic study and the first case revealing isochromosome 17q of an adult Wilms' tumor.     

A human adult Wilms' tumor. Histologic, ultrastructural, and cytogenetic analysis

The cytogenetic, histologic, and electron microscopic studies of an adult patient with Wilms' tumor are presented. Wilms' tumor (nephroblastoma) is a common renal tumor of childhood but is extremely rare in people over 15 years old. The histologic analysis of the patient's tumor, including both light and electron microscopic analysis, indicated that this tumor satisfies the histologic criteria for an adult Wilms' tumor, namely, blastemic cells that are immature renal parenchymal cells, embryonic tubular structures, and a scanty stromal component consisting of loosely arranged spindle cells. The tumor showed several ultrastructural features characteristic of adult Wilms' tumor, namely, markedly elongated mitochondria, autophagic vacuoles, and intracytoplasmic filaments. Karyotypic analysis was performed on the patient's peripheral leukocytes and tumor cells. The leukocytes showed no significant increase in gaps and breaks, and the patient appears to have a normal male karyotype. Some interesting chromosomal anomalies were observed in the cultured tumor cells: at least one chromosome 13, both chromosomes 22, and the X chromosome are missing, three markers are present, and there is a possible deletion of 12p.