Extrarenal Wilms' tumor with cerebellar metastasis in a four-year-old girl with spina bifida

This report documents the occurrence of an extrarenal nephroblastoma from which a cerebellar metastasis developed in a four-year-old girl with spina bifida. The second tumor became symptomatic two years after the resection of the primary, suggesting a treatment effect as a factor for the delay in the growing of the metastatic neoplasm. Histologic and ultrastructural features of the metastasis were similar to those described in Wilms' tumors of the kidney. The pathogenesis of this exceptional association, including malformation, malignancy, and unusual site of metastasis, is discussed.

Hemangioblastomas of the central nervous system--immunohistochemical and ultrastructural study

Immunohistochemical studies using immunoperoxidase staining for glial fibrillary acidic protein (GFAP), S-100 protein, and factor VIII-related antigen (VIII-RAg) were performed on 10 hemangioblastomas of the central nervous system to determine the origin of stromal cells. No cytoplasmic immunoreactivity for anti-GFAP, anti-S-100 protein, or anti-VIII-RAg was detected in most stromal cells. A small number of GFAP-positive cells were found only in the periphery of the tumor; they were thought to be trapped astrocytes or stromal cells taking up GFAP. Most stromal cells had abundant, clear cytoplasm with some microfilaments and lipid vacuoles. Cylindrical cytoplasmic processes and intermediate junctions were observed in some stromal cells, but most cells did not possess any junctional device. No stromal cell possessed any feature clearly suggesting endothelial cells or pericytes. Our immunohistochemical and ultrastructural investigations did not support the theories of stromal cell origin from astrocytes or endothelial cells. We concluded that stromal cells can be regarded as an aberrant cell type of angiogenic mesenchymal derivation.

Anaplastic ependymoma of the spinal cord in childhood. A case report

We report a 6-year-old girl with anaplastic ependymoma probably originating in the region of the conus medullaris and probably spreading retrogradely to the region of the interventricular foramen (Monro) through the cerebrospinal fluid (CSF). Since ependymoma of the spinal cord rarely occurs in children, and retrograde spreading is extremely rare, the histological features and mechanism of metastasis of the tumor are discussed.

[Immunohistochemical study on Rosenthal fibers in gliomas using anti-GFAP and anti-ubiquitin antibodies]

Immunohistochemically we investigated Rosenthal fibers (RFs) on specimen surgically removed from patients with glioma (three cerebellar astrocytomas, three optic gliomas, two spinal cord astrocytomas, one spinal ganglioglioma). Pathological diagnoses were pilocytic astrocytoma, fibrillary astrocytoma, and ganglioglioma. We utilized sections from the formalin-fixed paraffin-embedded tissues and stained them with H & E, PTAH, PAS as well as with anti-GFAP (glial fibrillary acidic protein) antibody (Ab) and two anti-ubiquitin Abs...anti-PHF (paired helical filament) monoclonal Ab (DF2) which recognizes ubiquitin (H. Mori in Science) and anti-ubiquitin polyclonal Ab provided by Dr. Haas. The primary antibodies were diluted with Tris-saline as follows: anti-GFAP (1:500), DF2 (culture medium without dilution), anti-ubiquitin (2 micrograms/ml). Sections were deparaffinized and incubated with primary antibodies overnight at room temperature. They were visualized by the avidin-biotin-peroxidase complex (ABC) procedure (Vectastain, Vector, USA) and counterstained with hematoxylin. Negative control sections were treated by omitting the primary antibodies. In the representative specimen we compared H & E, anti-GFAP and anti-ubiquitin staining on 3 microcrons serial sections. RFs were eosinophilic (bright red on H & E), purply-stained with PTAH (metachromasia), black with Heidemhein's iron-hematoxylin, and negative with PAS. Anti-GFAP Ab stained glial filaments diffusely in the cytoplasm and cell process of astrocytomas in every case. The peripheral parts of most RFs were intensely stained with anti-GFAP. The whole part of some RFs showed dark staining, and no part of a few RFs showed positive reactivity.(ABSTRACT TRUNCATED AT 250 WORDS)

Subependymoma of the thoracolumbar cord. Case report

Subependymomas are benign, usually asymptomatic, intraventricular tumors, the origin of which remains controversial. Spinal cord subependymomas are rare: a literature review yields 10 previous cases which are critically appraised in this report. A case of thoracolumbar intramedullary subependymoma is reported, and the histology, ultrastructure, and pre- and postoperative management are reviewed. Awareness that subependymomas may occur as a separate entity in the spinal cord should lead to increased frequency of diagnosis and a better understanding of the biological behavior of these tumors.

[Immunohistochemical study of schwannoma--with respect to the histogenesis of Antoni B area]

Sixty two cases of schwannoma were studied immunohistochemically and ultrastructurally for further understanding of the histogenesis of Antoni B area. For immunohistochemical study, the author used the antibodies against fibronectin (FN), factor XIIIa (XIIIa), and collagen type I and III. FN and XIIIa were positive with a fibrillar pattern in Antoni B area. Collagen type I and III were positive in the extracellular matrix of Antoni B area, but not in Antoni A area. Ultrastructurally, Antoni B area consisted of degenerative Schwann cells and fibroblasts. These findings closely resemble those of fibrogenesis seen in the wound healing process or in the stroma around tumor. The author concluded that the fibrogenesis occurring in Antoni B area reflects the stromal reaction against Antoni A area, in contrast to the previous studies that Antoni B area only represents degenerative change of Antoni A area.

[Electron microscopic observations of blood vessels in ependymoma]

The findings of an ultrastructural study of the blood vessels and their surrounding structures in ependymoma are demonstrated. Six surgically removed cases of ependymoma are investigated. The lumen of the blood vessels, especially in vascular rosettes is often wider than those of normal brain capillaries. The endothelial cells are structurally varied, but sometimes attenuated in many areas. Also, they often have several fenestrations. Moreover, they have increased pinocytotic vesicles and filaments, and contain occasional Weibel-Palade bodies, multivesicular bodies and other cytoplasmic organelles. The perivascular space is often wide, especially in intraspinal ependymoma, and filled with multiple layers of basal laminae permeated by electron, dense fluids. There are also collagenous fibers and Luse bodies. Basal lamina covering tumor cell surfaces is more distinct than other basal laminae. The tumor cells facing the blood vessel interestingly show structures similar to those of astrocytic vascular feet. The fenestration in the endothelial cells probably has an important role in the increased vascular permeability of ependymoma.

Intraspinal pigmented schwannoma with malignant progression

A case with recurrent pigmented intraspinal tumour with malignant progression is presented. The primary tumour grew around the nerve roots T9 and T10, was attached to dura and infiltrated the vertebral bone tissue. On light microscopy it was comprised of monomorphic cells with large amount of cytoplasmic pigment and many large pigmented globoid bodies. Mitoses were not observed. On electron microscopy, in addition to cytoplasmic melanosomes of regular size, macromelanosomes were numerous. The tumour cells were surrounded partially by basement membrane like material. On these bases a histological diagnosis of benign pigmented tumour of neural crest origin was suggested (a possible pigmented meningioma or pigmented schwannoma). The patient got a recurrence one year after the primary operation. Biopsy from the re-operation showed histologically the same type of tumour with more pleomorphic cells. Subsequently, the tumour grew progressively and metastases were observed in the lungs and in the skin. The patient died two years after the primary operation. The malignant progression of the tumour and other reports on similar tumours was most consistent with a diagnosis of malignant pigmented schwannoma and this was confirmed later on with immunohistochemical staining showing positive staining for basement membrane components, collagen type IV and laminin as well as a positive staining for S-100 protein. The present findings show that despite benign histological features these tumours can behave very aggressively and stress the need of more information on this type of tumour.

Cellular blue nevus ("melanocytoma") of the spinal meninges: electron microscopic and immunohistochemical features

A primary cellular blue nevus (melanocytoma) of the spinal canal in a 21-year-old woman is reported. Light microscopic examination revealed a melanotic neoplasm with histological patterns resembling schwannoma, dermal nevi, and neuroblastic-like tumor. The ultrastructural features of the neoplastic cells were similar to those in dermal blue nevi and melanomas. There was no evidence of arachnoidal cell differentiation. Immunohistochemistry revealed positive reactions for S-100 protein and neuron-specific enolase in many cells and no reactions for glial fibrillary acidic protein, cytokeratins, epithelial membrane antigen, 70-kD neurofilament protein, or Leu-7. Vimentin was strongly positive in the melanocytic cells as well as in the arachnoidal cells of involved meninges. The ultrastructural and immunohistochemical features support the nevoid nature of this tumor, which is frequently mislabeled as "melanotic meningioma."

Pseudoglandular schwannoma

The glandular schwannoma is a rare variant of schwannoma in which the focally occurring glands are lined by cells resembling intestinal or respiratory type epithelium, or ependyma. The schwannomas harboring these glands are usually malignant and usually arise in the setting of von Recklinghausen's disease. The case presented in this report is that of a 43-year-old man who had no evidence of neurofibromatosis, and developed a benign schwannoma that contained multiple well formed gland-like structures. The cells lining the glands, when examined ultrastructurally and histochemically, proved to be Schwann cells, a unique finding that may provide a clue to the histogenesis of the glandular schwannoma.

Ultrastructural findings in transplanted experimental brain tumors and their significance for the cytogenesis of such tumors

Tumors induced by transplacental action in the spinal cord of rats were transplanted into the brains of the same rat strain. They were followed up by electron microscopy during the first ten passages. Three architectural features were detected: First pure tumor parts, second myelin breakdown and phagocytosis, and third the resulting accumulation of resting macrophages. Architecture two and three were interpreted as result of considerable phagocytotic activity of tumor cells localized within the white substance of the brain and spinal cord. Only architecture one was considered to represent proper tumor. Since this was low differentiated and partial astrocytic differentiation only occurred around vessels to remarkable extent, the thesis is put forward that these transplacentally induced tumors correspond to human primitive neuroectodermal tumors.

A novel intradural extramedullary spinal cord tumor in young dogs

We have studied an unusual, spontaneous, intradural extramedullary spinal cord tumor in 12 dogs. Animals presented with paraparesis and ataxia early in life (11/12 ranged from 6 to 38 months of age) suggesting that these tumors may be congenital. Various breeds of dogs were represented with four cases in German Shepherds and three in retrievers; there was no sex predisposition. Post-mortem examinations revealed a single intradural mass consistently located between T10 and L2, which produced extensive compression of the spinal cord. Metastasis was never observed and significant pathological changes in other organs were lacking. Microscopic examination revealed solid sheets of ovoid to fusiform cells interspersed with areas of acinar and tubular differentiation. Some areas were rarified and focal squamous metaplasia was observed. Ultrastructural features included the presence of a continuous basal lamina, junctional complexes, microvilli and occasional cilia at the apices of acinar complexes. Immunocytochemical studies did not support a neurectodermal origin. At least 13 case reports of this entity have been previously published and have been designated ependymomas, medulloepitheliomas and neuroepitheliomas. A recent case was diagnosed as a nephroblastoma and we feel that this is an interesting and provocative diagnosis. These tumors could result from remnants of renal primordium which becomes trapped between the dura and the developing spinal cord. However, firm evidence of such a histogenesis is not yet at hand.

Paraganglioma of the filum terminale internum. Report of a case and review of the literature

A case of paraganglioma of the filum terminale is presented where normal sympathetic ganglion cells were seen in conjunction with tumour cells in a well-encapsulated tumour, suggesting a possible origin from heterotopic sympathetic ganglion.

Malignant rhabdoid tumor of the central nervous system

Originally described and most frequently reported in association with the kidney, the malignant rhabdoid tumor (MRT) is a highly aggressive neoplasm with distinctive morphologic features. Extrarenal sites reported for this neoplasm include the liver, thymus, and various soft tissue sites. Young infants are affected with rare exceptions. We report the case of a 3-month-old boy who presented with hyperirritability and increasing head size over several weeks. The patient died following a two-week hospital stay marked by development of seizures, paralysis, and apnea. At autopsy, significant findings were limited to the central nervous system. The subarachnoid space contained neoplasm throughout, with multiple areas of parenchymal invasion. A predominating intraparenchymal mass was present in the inferior cerebellum contiguous with the neoplasm in the subarachnoid space and probably represented the site of origin. Microscopically, the neoplasm was composed of a highly cellular monomorphic population of polygonal cells with roughly ovoid vesicular nuclei and conspicuous nucleoli. Variable amounts of cytoplasm were present, and many cells contained a single, well-demarcated eosinophilic hyaline globule adjacent to the nucleus. Ultrastructurally, the cytoplasmic globules were composed of whorled aggregates of intermediate filaments. Immunoperoxidase studies confirmed that the filaments were composed, at least in part, of vimentin. The morphologic and immunohistochemical features are diagnostic of MRT, an entity of unknown histogenesis that has not been reported previously as a primary neoplasm of the CNS.

Myxopapillary ependymoma of the filum terminale. A light and electron microscopic study

The histology of a myxopapillary ependymoma of the filum terminale in a 15-year-old girl was studied by light and electron microscopy. The neoplasm contained both papillary and compact areas of cell growth. The papillary regions consisted of vacuolated cuboidal cells arranged around hyaline/vascular cores that were variably mucin-positive. In the compact regions, the tumor cells were intensely immunoreactive for glial fibrillary acidic protein and occasionally formed perivascular pseudorosettes. Ultrastructural examination revealed interdigitating cell processes, sometimes resting on a basement membrane. Surface specializations included numerous microvilli and occasional cilia. The cilia had an abnormal microtubular pattern (e.g., 8 + 1, 7 + 0). The cytoplasm of the tumor cells contained numerous 7-10 nm intermediate filaments and large numbers of abnormal microtubular aggregates, consisting of 4 to 50 single microtubules enclosed by a limiting membrane. These microtubular aggregates may represent a characteristic feature of myxopapillary ependymoma of the filum terminale.

Multifocal spinal angiosarcoma after chordotomy

A male aged 60 is reported who, 5 years after chordotomy at the Th 2/3 level, developed acute paraplegia of the legs and a sensory transverse lesion due to an extradural tumour of the Th 1-4 level. Neuropathology revealed transverse necrosis of the thoracic spinal cord (Th 1-4) due to an intradural tumour at the upper thoracic and lumbar spinal levels, the thoracic malignancy arising at the site of the previous chordotomy, with a suture being observed within the tumour mass. Histology, positive immunostaining of tumour cells with Factor VIII antigen, a specific marker of endothelial cells and the ultrastructural demonstration of Weibel-Palade bodies in endothelial cells of the tumour vessels suggested a malignant mesenchymal tumour of angiosarcoma type presumably arising from the spinal meninges, and broadly invading the spinal cord. The usual relation of this extremely rare intraspinal vasoformative malignancy to previous chordotomy is discussed.

[Contribution of electron microscopy in the differential diagnosis of tumors of the meninges, brain and spinal cord]

Critical Evaluation of 200 tumours of meninges, brain and spinal cord showed that to be familiar with the ultrastructural features of meningioma and its variants was instrumental in differential diagnosis of other primary or secondary meningeal tumours (neurinoma, paraganglioma, xanthomatous and histiocytic tumours). A limited value of electron microscopy was found in astrocytoma and glioblastoma in contrast to its importance in low-differentiated ependymoma and oligodendroglioma. The examination had histogenetical and taxonomic values in medulloblastoma (CNS neuroblastoma and mixed tumours with a component featuring primitive neuroectodermal or neuroblastic differentiation). Ultrastructure was very important in the so-called primitive neuroectodermal CNS tumours where only the lack of conspicuous glial or neuroblastic differentiation confirmed the diagnosis. Electron microscopy was instrumental in rare primary CNS lymphomas as well as in some metastatic tumours.

Regulation of DNA synthesis and growth of cells derived from primary human meningiomas

We have studied the effects of insulin, epidermal growth factor (EGF), fibroblast growth factor (FGF), platelet-derived growth factor, and steroid hormones (estradiol, progesterone, and cortisol) on human meningioma cell proliferation and DNA synthesis in a serum-free culture system. The growth factors, particularly EGF and FGF, increased DNA synthesis in a dose-dependent manner as measured by [3H]thymidine incorporation, and they stimulated submaximal cell proliferation. No individual factor or combination of factors was able to successfully reproduce the effects of 10% fetal calf serum (FCS) on cell growth, although a combination of platelet-derived growth factor (5 units/ml) and EGF (10 ng/ml) synergistically stimulated DNA synthesis to near maximal levels. In addition, serum dependency was observed in studies involving the mitogenic effects of insulin, EGF, or FGF. Both EGF and FGF (10 ng/ml) maximally stimulated cell growth in the presence of 5% FCS. The effects of steroid hormones on cell proliferation, individually or in combination with growth factors or charcoal-treated FCS, were also evaluated. Estradiol (100 nM) significantly increased cell number over control values only in the presence of charcoal-treated FCS; no effects of progesterone or cortisol on cell proliferation were observed. In conclusion, both EGF and FGF stimulated cell proliferation and DNA synthesis in human meningioma cultures in a serum-free system, whereas steroid hormones were without effect. It appears that additional serum components are required for both estradiol-stimulated growth and for maximal proliferation of human meningioma cells under serum-free conditions.

Fine needle aspiration cytology of hemangioblastoma of the spinal cord. Report of a case with immunocytochemical and ultrastructural studies

The cytologic features of a hemangioblastoma of the spinal cord diagnosed by an intraoperative fine needle aspiration (FNA) biopsy are reported in a 66-year-old man with a long-standing history of Charcot-Marie-Tooth disease. A dual population of delicate branching vascular channels associated with nearby coarsely vacuolated stromal cells was appreciated in the smears. Histologic, immunocytochemical and ultrastructural studies demonstrated three cell types comprising the tumor: endothelial cells, pericytes and stromal cells. Factor VIII-related antigen positivity, vimentin positivity and glial fibrillary acid protein negativity support the contention that all three types of tumor cells may arise from a common angiogenic mesenchymal ancestry. A discussion of the expected aspiration cytologic findings of other tumors of the spinal cord is also presented. FNA biopsy of suspected hemangioblastoma should be performed with utmost caution due to the possibility of extensive intraoperative bleeding, such as we experienced following sampling of this tumor.

Ultrastructure of chordoma. A case report

A 50-year-old male developed a sacro-coccygeal chordoma. Prior to the surgery, he had experienced back-pain, numbness of the right thigh and difficulty in voiding and defecation. Total excision of the mass was done and all symptoms were relieved. The light microscopic examination revealed a chordoma. The ultrastructural study was performed with particular interest in physaliferous cells. The fine structure disclosed the prominent associations of mitochondria and rough endoplasmic reticulum. The mitochondria showed irregularities in sizes and shapes but did not attenuate as much as previously reported. The vacuoles that were observed by light microscopy in physaliferous cells were both extra-cellular and intra-cellular and contained finely granular material of acid mucopolysaccharides probably of chondroitin type. The presence of both subplasmalemmal linear densities (SLD) and pinocytic vesicles was consistent with the histogenetic conviction that the tumor arose from mesodermal derivatives.

Myxopapillary ependymoma. A clinicopathologic and immunocytochemical study of 77 cases

The study involved 77 myxopapillary ependymomas of the spinal cord encountered during a 60-year period (1924-1983). This variant of ependymoma was, with few exceptions, limited to the lumbosacral region, particularly the filum terminale. The male:female ratio was 1.7:1, and the mean age at diagnosis was 36.4 years (range, 6-82); at presentation, 15 (19%) of the patients were in the first two decades of life. The duration of symptoms ranged from 1 month to 30 years; the most frequent complaint was low-back pain, and eight patients had undergone prior "disc surgery." Generally, myelographic block was disclosed. Preoperative cerebrospinal fluid protein levels averaged 2462 mg/dl. Myxopapillary ependymomas are slow-growing tumors that show no significant tendency to histologic dedifferentiation. Despite some variation in cytologic features and the presence of atypia and modest mitotic activity in most cases, the gross characteristics of the tumors appear to be of greater prognostic significance than the histologic features. Tumors that were encapsulated (25%) and amenable to intact, total surgical removal had a recurrence rate of 10%, whereas those that were removed either piecemeal (34%) or subtotally (41%) had recurrence rates of 19%. Overall survival, however, was more closely related to residual disease; total removal of tumor, whether intact (encapsulated) or piecemeal, resulted in longer survival (19 years) than did subtotal resection (14 years). Patients who died (6.5%) did so after a prolonged course marked by multiple recurrences. Radiotherapy may be of particular benefit to patients whose tumors are not amenable to intact total removal.

Myxopapillary ependymoma. A clinicopathologic and immunocytochemical study of 77 cases

The study involved 77 myxopapillary ependymomas of the spinal cord encountered during a 60-year period (1924-1983). This variant of ependymoma was, with few exceptions, limited to the lumbosacral region, particularly the filum terminale. The male:female ratio was 1.7:1, and the mean age at diagnosis was 36.4 years (range, 6-82); at presentation, 15 (19%) of the patients were in the first two decades of life. The duration of symptoms ranged from 1 month to 30 years; the most frequent complaint was low-back pain, and eight patients had undergone prior "disc surgery." Generally, myelographic block was disclosed. Preoperative cerebrospinal fluid protein levels averaged 2462 mg/dl. Myxopapillary ependymomas are slow-growing tumors that show no significant tendency to histologic dedifferentiation. Despite some variation in cytologic features and the presence of atypia and modest mitotic activity in most cases, the gross characteristics of the tumors appear to be of greater prognostic significance than the histologic features. Tumors that were encapsulated (25%) and amenable to intact, total surgical removal had a recurrence rate of 10%, whereas those that were removed either piecemeal (34%) or subtotally (41%) had recurrence rates of 19%. Overall survival, however, was more closely related to residual disease; total removal of tumor, whether intact (encapsulated) or piecemeal, resulted in longer survival (19 years) than did subtotal resection (14 years). Patients who died (6.5%) did so after a prolonged course marked by multiple recurrences. Radiotherapy may be of particular benefit to patients whose tumors are not amenable to intact total removal.

Central nervous system involvement in congenital visceral fibromatosis

Congenital visceral myofibromatosis is an uncommon disorder characterized by multiple tumors of myofibroblastic origin in the neonatal period. The natural history of the disorder has been well delineated. The myofibroblast is the cell of origin of the tumor. This is a report of a patient in whom multiple mesenchymal tumors occurred in the CNS as well as in other organs. Light and electron microscopic findings of the CNS lesions are similar to those of the somites and viscera.