Neural variant of fetal rhabdomyoma and naevoid basal cell carcinoma syndrome

A case of intramedullary melanocytoma of the medulla oblongata; which has not been hitherto reported, is presented. The tumor ran on a slow progressive course. The patient died of pneumonia seven months after the operation. MRI findings did not specify this tumor as they were not distinct from those of malignant melanoma. The tumor was totally black and was not attached to the dura. Microscopically, the neoplastic cells were uniform in size and possessed abundant melanin granules in their cytoplasm. Mitosis was very rare. The ultrastructure of the tumor cells showed many melanosomes at varying stages of maturation. The melanocytoma in the eloquent region has an unfavorable outcome.     

Potential of densitometric measurement in selected pediatric subject

The ultrastructure and clinical significance of the basement membrane (BM) are still unclear in esophageal cancer. In this report, we examined the ultrastructure of the BM and microstructures related intercellular adhesion in squamous cell carcinoma of human esophagus using a transmission electron microscope, and investigated their clinical significance. BM was absent in 38% of the examined cases and the frequency or the presence of the microstructures of cancer cells of the infiltrating margin (CCIM) was negatively related to the presence of BM (BM-P); CCIM of BM-P tumors often had smaller number per cell of desmosomes and cytoplasmic processes. These results indicate that CCIM of BM-P tumor are in an 'inconvenient status' for tumor cells to form a firm group. In the intercellular space between CCIM and BM or surrounding stromal cells, all of the CCIM of BM-P tumors had hemidesmosomes, but not those of BM absent (BM-A) tumors. Though no statistical significant difference was found in our clinical observation between BM-P and BM-A tumors, the present study suggested that a considerable proportion of cancer cells have abnormal intercellular adhesiveness via a mechanical mechanism related to the presence or absence of BM.     

Mitochondrial abnormalities in the cells of myeloma patients

Mitochondrial abnormalities in the myeloma cells of 52 patients are described. They included increased number, bizarre shape, alterations in their internal ultrastructure and vacuolization. There was no correlation between the type of myeloma or the severity of the disease and the observed abnormality of the mitochondria. The possible connection between the damaged mitochondria and the function of the tumor cells is discussed.     

Rigid osteosynthesis with the AO plate and Phemister''s spongioplasty in secondary treatment of diaphyseal gunshot fractures

To clarify the histogenesis and differentiation potential of central neurocytoma, a pathological investigation of seven tumors from three patients was conducted using immunohistochemistry and ultrastructural analysis in addition to systematic in vitro studies. Six tumors were studied immunohistochemically and five were examined ultrastructurally. All cases that were immunostained were positive for synaptophysin in nuclear-free neuropil islands. In five tumors, a few tumor cells, in addition to reactive astrocytes, were positive for glial fibrillary acidic protein (GFAP). Vimentin staining was also positive in a few tumor cells of five specimens. Neurofilament staining was always negative. All cases for which ultrastructure was examined showed various synaptic abnormalities. Cultured cells were subdivided into three distinct tumor cell types: neuronal cells which stained for neurofilament proteins with neurosecretory granules; small flat undifferentiated cells with a high nuclear-cytoplasmic ratio and scant cytoplasmic organelles; and small round or multipolar astrocytic cells with 10-nm intermediate filaments which stained for GFAP. Our tissue culture studies disclosed that cultured neurocytoma cells form a cellular mosaic similar to subependymal plate layers that are composed of mitotically active cells, neurons and glia.     

Vacuolated meningioma. A light and electron microscopic study

Two unusual cases of meningioma with extensive vacuolization have been studied by light and electron microscopy. There were two kinds of vacuoles in the tumor cells which had the characteristic ultrastructure of meningioma as well. The smaller intracytoplasmic vacuoles were lipid droplets, while the larger, more prominent vacuoles were found to be extracellular spaces probably containing plasmatic fluid. The tumor cells were very much stellate with extremely thin and long cytoplasmic processes having desmosome junctions and forming cavernous intercellular spaces, some of which contained collagen fibers and fibrils. Although the xanthomatous change has been well known, the latter features provide a resonable interpretation for the histology of the present tumors and fat-negative vacuoles in the ordinary meningiomas. The picture may be recapitulation of the subarachnoid structure. Furthermore, recognition of this type of meningioma is practically important especially in frozen section diagnosis not to misinterpret the tumor as liposarcoma, chordoma or metastatic adenocarcinoma.     

The ultrastructure of intermediate type trophoblast cell

Transmission electron microscopy was used to clarify the detailed morphology of the "intermediate type" trophoblast cell in normal and tumor issue. 67 normal placental villi specimen, 10 placental bed specimens and 10 malignant mole, 10 hydatidiform mole, 5 choriocarcinoma specimen (the last three types taken before chemotherapy) were examined. Results showed that the transitional type trophoblasts of the placenta were developed from cytotrophoblasts through differentiation and fusion to syncytiotrophoblasts which showed features of maturation and aging, having features of cytotrophoblast nuclei and syncytiotrophoblast cytoplasm. The transitional trophoblast of placental bed showed similar morphology as that of transitional type cells of villi. The morphology of transitional type cells of villi. The morphology of transitional type cells of trophoblastic tumors had both normal morphology and cellular hyperplasia, atypia and features of tumor ultrastructure. The prominent feature was the high electron density of the granules and polymorphic cysts crowded in villi, demonstrating that the morphology of "intermediate type" trophoblasts in placental and tumor tissue are similar, whereas heterotype cellular morphology is present in varying degrees in tumor tissue.     

The ultrastructure of liposarcomas with attention to "dedifferentiation"

Liposarcomas are among the most common soft tissue sarcomas. It is recognized that dedifferentiation can occur within a well-differentiated liposarcoma, but there is limited information concerning the ultrastructure of the dedifferentiated cells. A series of 8 cases has been studied by light and electron microscopy and compared with well-differentiated, myxoid, and pleomorphic liposarcomas. No definite evidence of lipoblastic differentiation could be found in the dedifferentiated cases. The tumor cells resembled atypical cells in the well-differentiated liposarcomas, supporting the close relationship between these two types of tumors. However, since no conclusive line of differentiation could be found in the dedifferentiated cases, this study supports the contention that these neoplasms are undifferentiated counterparts of well-differentiated liposarcomas.     

Light microscopic and ultrastructural observations of a metastasizing malignant epithelioid schwannoma

The light microscopy and ultrastructure of a malignant epithelioid schwannoma are described. Characteristic cells resembling perineural elements with various degrees of differentiation were observed. Primitive epithelioid cells contained scant ergastoplasm, and few tubules and filaments, but did have abundant free ribosomes and Golgi membranes. Also noted were junctional complexes and focal fusion of plasma membranes, basal laminae were absent. Better differentiated cells were completely limited by a well-developed basal membrane and had an abundance of intracytoplasmic filaments and multiple pinocytotic vesicles. The intercellular ground substance was composed of numerous fine collagen fibrils and amorphous, basement membrane-like, electron-dense material. A striking ultrastructural similarity of the tumor cells to those encountered in ethylnitrosourea-induced malignant schwannomas in rats was noteworthy.     

Effect of vagotomy on the ultrastructural organization of the enterochromaffin cells of the rat duodenal mucosa

Detailed investigation of the ultrastructure of the enterochromaffine cells of the duodenal mucous membrane was conducted by electron microscopy. These cells were studied 7, 14, 28, and 56 days after bilateral subphrenic vagotomy. Vagotomy resulted in the alteration of the ultrastructural orgainzation of the enterochromaffine cells. These changes were due to disturbances of 5-hydroxytryptamine (serotonine) secretion. The changes in the ultrastructure of the enterochromaffine cells were most expressed 7 and 56 days after the operation. Temporary and relative normalization of the ultrastructure was observed in 28 days.     

Nodular basal cell carcinoma in vivo vs in vitro. Establishment of pure cell cultures, cytomorphologic characteristics, ultrastructure, immunophenotype, biosynthetic activities, and generation of antisera

BACKGROUND AND DESIGN: In this study we developed an in vitro model of nodular basal cell carcinoma (BCC). We obtained pure cultures of BCC cells and compared the morphologic characteristics, ultrastructure, immunophenotype, and behavior of cultured tumor cells with those of their in vivo counterparts. Tumors were excised from patients undergoing Mohs micrographic surgery. We established 69 primary cell cultures from 32 patients with nodular BCC. RESULTS: Three cell types grew in primary cultures: fibroblasts, normal-appearing keratinocytes, and cells with dual (spindle and epithelioid) morphologic characteristics. Contaminating fibroblasts were removed using 0.125% trypsin-0.02% edetic acid, and normal-appearing keratinocytes were cornified and eliminated by temporarily increasing the concentration of calcium in the growth medium. The cells with dual morphologic characteristics remained intact and exhibited relentless growth in pure cultures. That these seemingly immortal cell strains represent true nodular BCC was demonstrated by (1) their biphasic morphologic characteristics and very slow cell growth rate, (2) their capability for anchorage-independent growth in soft agar, (3) their ultrastructural similarities to freshly excised nodular BCC, (4) their ability to generate antibodies selectively labeling nodular BCC tumor nests in vivo, and (5) their immunophenotypic similarities to BCC in vivo on more than 20 different cell markers. CONCLUSIONS: This study provides a simple technique for establishing pure cell cultures of nodular BCC and describes extensively the in vitro parameters of tumor cell growth. The striking differences in behavior of cultured tumor cells in the presence or absence of normal-appearing keratinocytes suggest that normal human epidermal keratinocytes can suppress the growth of BCC cells.     

Establishment of tumor cell culture (ILA) derived from hamster pancreatic islets treated with BOP

ILA cells were established from tumors induced by the pancreatic carcinogen N-nitrosobis(2-oxopropyl)amine (BOP) in hamster islets. The proliferation, morphology, karyotype, immunoreactivity with certain antibodies and growth factor secretion of these tumor cells were compared with the same parameters in tumor cells induced by BOP in hamster ductal cells (TAKA-1-BOP) established in a previous study. Minor differences were found in the morphology and ultrastructure of the 2 cell lines. Contrary to TAKA-1-BOP cells, ILA cells did not express cytokeratins 8.13, 13 or 18 but did express DU-PAN-2 and TAG-72, 2 known human pancreatic cancer-associated antigens. No endocrine cell markers were expressed. A significant difference also was found in the chromosomal pattern in that there were more abnormalities and marker chromosomes in ILA cells than in TAKA-1-BOP cells and the Y or X chromosomes were missing in ILA cells. ILA cells produced TGF-alpha, IGF-I, bombesin and gastrin and expressed specific binding sites for hEGF. TGF-alpha secretion from ILA cells was much greater than that from TAKA-1-BOP cells. Our results indicate that pancreatic cancer cells grown in vitro are not a single clone. We conclude that there are some genetic and biological differences between tumors arising from pancreatic duct and islets and that pancreatic ductal adenocarcinomas originating from islets have a profound malignant potential.     

Epithelioid angiosarcoma of bone

Angiosarcoma of bone is a rare, high-grade sarcoma of vascular origin. This article describes an epithelioid angiosarcoma in the humerus of a 48-year-old man. A multilocular osteolytic lesion with undefined margins and destroyed cortical and medullary bone, associated with a large soft tissue mass was demonstrated radiologically in the proximal metaphysis of the right humerus. The tumor, resected by amputation, was composed mostly of proliferating malignant cells with an epithelioid morphology. It had a predominantly sheet-like growth pattern, and an occasional pseudoglandular or alveolar arrangement, mimicking an adenocarcinoma. The dilated anastomotic vascular spaces lined by epithelioid endothelial cells and the intracytoplasmic lumina/vacuoles that sometimes contained erythrocytes suggested focal endothelial differentiation. On immunohistochemical investigation, many neoplastic cells expressed cytokeratin and endothelial markers: factor-VIII related antigen, CD31, and UEA-I. The ultrastructure of the tumor was consistent with that of an angiosarcoma. Our patient died of disease shortly after the diagnosis, implying an aggressive clinical course. Awareness of the existence of skeletal epithelioid angiosarcoma, combined with the identification of intracytoplasmic lumina, or at least small vasoformative foci, and immunohistochemical positivity for endothelial markers provide the best guide for distinguishing this tumor from metastatic carcinomas.     

Conjunctival ultrastructure in Niemann-Pick disease type C

A 5-year-old girl with Niemann-Pick disease type C had normal eyes but the conjunctival ultrastructure was abnormal. Lamellar cytoplasmic bodies, characteristic of Niemann-Pick disease, were found in epithelial cells, stromal fibroblasts, endothelial cells, and pericytes of the stromal capillaries. The basement membrane of the capillaries was multilayered. The Golgi apparatus was unusually well developed. The combination of ocular findings and conjunctival ultrastructure may be helpful in the differential diagnosis of Niemann-Pick disease and its subtypes.     

Ultrastructure of endometrium during low-dose gestagenic anticonception (author's transl)

31 women (average age, 26 years) were administered a modified low dosage gestagen contraceptive, containing .3 of norethisterone for an average period of 10.6 months. Changes in the ultrastructure of the endometrium were studied throughout this period. Changes in both parts of the ultrastructure, the fibrose and epithelial parts, were revealed in comparison to material taken before use of the preparation. Changes in the stromata cells were particularly of a gestagenic character. Epithelial cells also demonstrated a particularly gestagenic stimulation.     

Meningioma and intracranial hemangiopericytoma. A comparative electron microscopic study

Electron microscopic study of 2 intracranial hemangiopericytomas and 7 meningiomas revealed fundamental morphologic differences between the 2 neoplasms. The most significant finding in hemangiopericytoma was the presence of ultrastructure features suggesting leiomyoblastic differentiation. These included characteristic fusiform intracytoplasmic and submembranous dense bodies, abundant cytoplasmic filaments, elongated cells with blunt-ended nuclei and juxtanuclear polarization of organelles. This observation is considered highly significant as an indicator of the pericytic nature of this tumor. In addition, hemangiopericytoma cells sometimes were arranged in spirals around pools of basement membrane-like material, perhaps a manifestation of the biologic capability of the cells to synthetize such material. Meningioma cells displayed as their main feature an ability to produce surface membrane specializations including interdigitations, desmosomes, zonulae adhaerentes and gap functions. Sometimes the last 3 elements were linearly juxtaposed forming junctional complexes similar to those seen in certain epithelia. It is suggested that the characteristic whorls of meningioma are the result of cell interconnections arising from the specialized junctional attachments. Thus the distinctive morphology of the 2 neoplasms appears to derive from basic biologic properties of their elements.     

Ultrastructure of the cellular patches of the arachnoid membrane of the human brain (concerning the origin of the arachnoid-endothelial cleavages of the cerebral dura mater). Electron microscopic study

The ultrastructure of cellular spots was studied--growths of the external arachnoidendothelial layer of the arachnoid membrane of the human cerebral hemispheres. The peculiarities of their ultrastructure depending on the stage of their development were revealed. "Young", cellular spots were formed by accumulations of osmiophobic round-shaped cells that are lined from the outside by osmiophilic cells like the whole of the arachnoid membrane surface. "Mature" cellular spots contain great number of oxmiophobic (viable) cells located in a immediate proximity of the subdural space, and they form the main source of viable arachnoidenodthelial cells found in the subdural fluid. The author believes that these cells penetrate together with the subdural fluid flow into the dura mater where, under specific conditions, they may become a source of arachnoidendothelial chippings.     

Ultrastructure of N-dibutylnitrosamine-induced tumors of the urinary bladder in European hamsters

European hamsters were treated sc with 0.025 the median lethan dose of N-dibutylnitrosamine. The induced neoplasms of the urinary bladder (transitional cell carcinomas and squamous cell carcinomas) were examined electron microscopically. Their ultrastructure indicated these tumors to be different developmental stages of the same type of tumor rather than two fundamentally different types of neoplasm.     

The G401 cell line, utilized for studies of chromosomal changes in Wilms' tumor, is derived from a rhabdoid tumor of the kidney

The histology, ultrastructure, and messenger RNA expression of heterotransplants derived from the G401 cell line (American Type Culture Collection) have been characterized by comparison with Wilms' and rhabdoid tumors of the kidney. This analysis illustrates that the properties of G401 heterotransplant were consistent with a rhabdoid phenotype rather than that of a Wilms' tumor. The G401 cell line has been utilized in recent experiments to demonstrate the central role of chromosome 11 in Wilms' tumor. However, the present results suggest that these experiments may be more relevant to define the involvement of chromosome 11 in rhabdoid tumor of the kidney, a malignancy distinct from Wilms' tumor. This is clinically relevant since the rhabdoid tumor of the kidney is very aggressive and associated with an extremely poor prognosis.     

Microsphere embolism-induced changes in noradrenaline release in the cerebral cortex in rats

A human cell line LMS6-93 has been established from a leiomyosarcoma (LMS). Characteristics for ultrastructure, growth characteristics, cell cycle distribution, karyotype, protein expression detected by immunohistochemistry (IHC), p53 mutational status and liposomal transfection behaviour were studied and determined. The primary tumor was clearly positive for á-smooth muscle type actin and desmin in moderately differentiated areas and indicated a loss of myogenic differentiation in other regions and therefore was classified as a poorly differentiated LMS. The cell line LMS6-93 contains mainly polymorphic spindle shaped or polygonal tumor cells which possess the characteristics of primitive mesenchymal cells, based on their morphology and positive reaction with an antibody to vimentin. IHC staining for S100, synaptophysin A, NSE, neurofilament proteins and cytokeratins were negative. Cytogenetic analysis revealed in the cell line diploid karyotypes comparatively close to several structural and numerical aberrations for chromosomes 2, 5, 6, 9, 10, 12, 14, 17, 18, 20, 22, and Y. IHC positivity was found for the tumor suppressor protein Rb and the oncogene product MDM2. In a p53 mutational analysis a 1 bp insertional mutation in exon 6 (G insertion in codon 215) was detected and confirmed in the original primary tumor. The other p53 allele appears to be wild-type as indicated in Western hybridization. Using different cationic lipid formulations complexed with a reporter expression vector (GFP) successful transfection into LMS6-93 cells was observed. The highest transfection rates (20-30% GFP expression in the viable cell population) were obtained with lipofectin. These results suggest that LMS6-93 functions as a good in vitro model for transfection studies on an LMS cell line carrying a heterozygous p53-frameshift mutation.     

Occupational exposure to drugs. General considerations]

The authors studied the ultrastructure of the esophagus lining epithelial cells of the snake Xenodon merremii. The initial shows ciliated wedge shaped cells and goblet cells which are gradually displaced by columnar ones in the posterior third of the organ. Other cellular types, such as basal, argentaffin and argyrophil cells can be found throughout the esophagus mucosa.