Characterization of cultured neurofibroma cells derived from von Recklinghausen's disease.

We have examined the cytoplasmic distribution of actin and fibronectin in cultured neurofibroma cells (NF cells) derived from a patient with von Recklinghausen's disease by using phase contrast and indirect immunofluorescence microscopy. NF cells were larger in size and more dendritic in shape compared to normal human dermal fibroblasts. NF cells also showed abundant granular staining of actin and a decrease in the linear staining pattern of fibronectin. Furthermore, employing a colony-formation assay on the top of an agar-gel in the presence of fibroblast growth factor (FGF), normal fibroblasts showed a significant number of colonies, whereas NF cells did not demonstrate colony formation even after addition of FGF. These findings suggests that NF cells from patients with von Recklinghausen's disease may have different characteristics when compared with normal fibroblasts, and that NF cells are similar to transformed cells with regard to their actin and fibronectin distribution.

Segmental neurofibromatosis: immunocytochemical analysis of cutaneous lesions.

Cutaneous lesions from three patients with segmental neurofibromatosis were evaluated. Routine histologic studies revealed the presence of redimentary neural structures within an abundant collagenous matrix. The majority of the cells in all three cases expressed S-100 protein, suggesting their identity as Schwann cells. The stromal component stained positively for fibronectin and type IV collagen; the latter indicated the presence of basement membrane material. Embedded in the tumor mass were glandular epithelial structures that stained with epithelial membrane antigen antibody. Staining for factor VIII-related antigen revealed vascular endothelium and multiple scattered mast cells. In one case strands of cells stained with antibodies to desmin, suggesting muscle cell differentiation. This case may represent a distinct subset of neurofibromas.

The distribution of alpha and beta subunits of S-100 protein in malignant schwannomas arising from neurofibromatosis of von Recklinghausen's disease.

The immunohistochemical localization of the alpha and beta subunits of S-100 protein in 4 cases of the malignant Schwannomas arising from von Recklinghausen's disease was investigated by the indirect immunoperoxidase method. S-100 alpha-positive cells were few in presumably normal peripheral nerves, moderate in numbers in plexiform neurofibromas and numerous in malignant Schwannomas. In contrast, S-100 beta immunoreactivity, abundantly detected in normal peripheral nerves and plexiform neurofibromas, was completely negative in all of 4 cases of malignant Schwannoma. In addition, double immunostaining method for both subunits revealed their simultaneous existence in cells in the normal nerves and neurofibroma. These results suggest that malignant change of Schwann cells convert their subunit composition of S-100 protein from beta to alpha in these malignant cells. Although the mechanisms for the proportional conversion of the subunits are as yet undetermined, the immunoreactivity of S-100 alpha subunit may be a useful marker for Schwannoma in malignancy.

Inherited multiple meningiomas: a clinical, pathological and cytogenetic study of an affected family.

The clinical features of a family with inherited multiple meningiomas as the major manifestation of neurofibromatosis are presented. The value of noninvasive radiological screening investigations is emphasised. The results of cytogenetic and pathological studies on the family are presented and discussed with a review of the relevant literature.

Growth-promoting factors in neurofibroma crude extracts.

Crude extracts of neurofibromas from two unrelated neurofibromatosis (NF) patients were prepared by mincing, homogenizing, and ultracentrifugation in the absence of added solvents. Explant cultures of neurofibromas from other NF patients were grown at low density in culture medium with and without neurofibroma extract supplementation. Differences in growth were monitored by comparing monolayer densities, colony counts, or uptake of [3]H-thymidine. A consistent enhancement of growth rate was demonstrated, and titration curves showed an increasing effect with increasing dosage (ranging from 1.5 microliter/ml to 25 microliters/ml). However, the extract could not substitute for fetal bovine serum. As determined by microscopic examination of Giemsa-stained petri dishes, small spindle-shaped cells, distinct in morphology from ordinary fibroblasts, were the overwhelmingly predominant cell type in most extract-treated cultures. While the specific identity of the growth factor(s) involved is unknown, the following may be stated: The presence of one or more growth factors that may act in an autocrine or paracrine manner in neurofibromas in vivo is demonstrated. There is a preferential effect of such a factor on spindle-shaped cells (presumably Schwann cells), allowing for the selective enrichment of these cells in vitro. There is an enhanced yield of clones derived from single cells, allowing further analysis of the cellular heterogeneity of neurofibromas at the biochemical and molecular levels. These considerations should help to distinguish between those models for neurofibroma growth that emphasize secondary somatic mutations (including allelic exclusion) on the one hand, and cellular interaction on the other hand.

Duodenal and ampullary carcinoid tumors. A report of 12 cases with pathological characteristics, polypeptide content and relation to the MEN I syndrome and von Recklinghausen's disease (neurofibromatosis).

Twelve duodenal carcinoid tumours are presented, 4 of them located in the ampulla. Symptoms included the Zollinger-Ellison syndrome (4 patients), the carcinoid syndrome (1 patient), mechanical obstruction (3 patients), bleeding (1 patient) and abdominal pain (1 patient). Two further tumours were detected by chance. Three patients with the Zollinger-Ellison syndrome had additional endocrine tumours characteristic of the MEN I syndrome. In 2 of them the duodenal carcinoids were of very small size and were multiple. They were observed in close proximity to focal areas of endocrine cell hyperplasia. Immunohistochemical investigations showed gastrin and somatostatin to be the predominant polypeptide hormones produced by these tumours. No somatostatinoma syndrome was encountered. In half of our cases additional production of insulin, VIP or even calcitonin in smaller amounts was found. Two of our patients had cutaneous manifestations of von Recklinghausen's disease and in both of them the carcinoid was located in the ampulla. One of these patients also had a pheochromocytoma.

Basement membrane proteins, interstitial collagens, and fibronectin in neurofibroma.

The distribution and nature of extracellular matrix proteins in neurofibroma tissue was studied by indirect immunofluorescence, immunoelectron microscopy, immunoblotting, and rotary shadowing. The most striking feature was an extensive network of basement membranes localized mainly around Schwann cells and small blood vessels. The major components, collagen IV, laminin, and nidogen, were mainly deposited in the lamina densa. Some laminin and nidogen could be extracted with 0.5 M NaCl and were shown by electrophoresis to have the characteristic chain and fragment patterns described previously for these proteins isolated from the mouse Engelbreth-Holm-Swarm (EHS) sarcoma. Fragments of collagen IV and collagen VI were solubilized by limited proteolytic digestion and identified after rotary shadowing. The more remote interstitial regions of the tumor contained cross-striated collagen fibrils which were composed of collagen III (diameter, 20-30 nm) or collagen I (diameter, 40-50 nm). Collagen fibrils thicker than 80 nm were not found. The interstitial regions also contained collagen VI as a fine filamentous network near cells and between collagen fibrils. Deposits of fibronectin were rather small and showed a scattered distribution. The data indicate that Schwann cells contribute considerably to matrix production in neurofibroma which may therefore be a suitable model for studying basement membranes of neuroectodermal origin.

[Malignant schwannoma arising in Recklinghausen's disease--report of 4 cases].

Four cases of malignant schwannoma arising in Recklinghausen's disease are described. The 4 patients, aged 38, 41, 44 and 38, 2 men and 2 women, had up to child-head-sized tumors in the neck, back, axilla and retroperitoneum. Oncostatic chemotherapy and irradiation were ineffective against the malignant schwannoma. In three, surgically tumor-resected cases, local recurrence and rapid tumor growth occurred. Histologically, malignant schwannoma was characterized by the presence of a few collagen fibers among the tumor cells, but abundant argentaffin fibers. Numerous mast cells are frequently seen in neurofibroma, but almost never in malignant schwannoma. In Case 3, with mild atypism, tumor cells were positive for S100 protein.

Collagen synthesis in cells cultured from v. Recklinghausen's neurofibromatosis.

Subcutaneous tumors of a patient with v. Recklinghausen's neurofibromatosis contained about 31% collagen calculated on the basis of lipid-free dry weight. Slices of the tumors synthesized collagen at a rate (4.7-8.5% from total protein) which was higher than that of the skin slices (2.8-5.9%). Neurofibromatosis cells were cultured from tumors of two patients. They synthesized relatively much more collagen than cultures of skin fibroblasts of the same patient or of healthy age-matched control persons. The second patient's cultures were studied in detail. The cell densities of these cultures were higher and expressed more variation than the densities of control skin fibroblasts. Ion exchange cellulose chromatograms, SDS-polyacrylamide gel electrophoresis and 3-hydroxyproline analysis of the radioactive proteins made by the cultures indicate that most of the collagenous proteins resembled type I collagen. High proliferative capacity and high collagen synthesis of selected neurofibromatosis cells explains the growth of solid tumors.