Maturation of cerebellar neuroblastoma into ganglioneuroma with melanosis. A histologic, immunocytochemical, and ultrastructural study

Cervical ganglioneuroblastoma in a new born Japanese Black calf

This case report describes a congenital ganglioneuroblastoma in a 38-day-old male Japanese Black calf. The cervical multinodular mass was present at birth and grew rapidly. The cut surface was pale gray-to-yellow and had a gelatinous appearance. Hemorrhagic cysts of various sizes were observed in the nodule. Histologically, the mass contained clusters of neuroblastic cells, ganglionic cells, and Schwann-like cells. Immunohistochemically, the ganglionic cells showed strong positivity for neuron-specific enolase, neurofilament, synaptophysin, and chromogranin A, whereas the Schwann-like cells strongly expressed S-100, glial fibrillary acidic protein, and vimentin. Ultrastructurally, neurosecretory granules resembling catecholamine were observed in the neuroblastic and Schwann-like cells. Based on the pathology, the diagnosis was congenital cervical nodular ganglioneuroblastoma.

[Molecular methods in diagnosis of poorly differentiated malignant brain tumors in children]

The histological diagnosis of malignant brain tumors in children is a complex process. In some cases, glioblastoma, primitive neuroectodermal tumor of the central nervous system, and atypical teratoid/rhabdoid tumor have a histological type similar to that of small blue round cell malignant tumor. Despite the similar histology, biological properties and approaches to treatment, these neoplasms are completely different and require their own treatment protocols. We retrospectively reviewed the most malignant types of childhood tumors and analyzed our own experience to propose a diagnostic algorithm for intracerebral small blue round cell malignant tumors in children based on the use of immunohistochemistry and fluorescence in situ hybridization.

Post-chemotherapy maturation in supratentorial primitive neuroectodermal tumors

Maturation in central nervous system embryonal tumors is an uncommon phenomenon that is mainly reported in the context of specific histological subgroups of medulloblastoma. In this report we describe two cases of histological maturation in patients with supratentorial primitive neuroectodermal tumor with strikingly different outcomes. We discuss the potential impact of such findings on treatment and outcome.

A phase II study of metronomic oral topotecan for recurrent childhood brain tumors

BACKGROUND

The prognosis for recurrent or refractory brain tumors in children is poor with conventional therapies. Topotecan is a topoisomerase I inhibitor with good central nervous system (CNS) penetration following oral administration. Increased efficacy of topotecan has been demonstrated with prolonged low-dose daily treatment in pre-clinical models. To investigate further this drug delivered orally in pediatric CNS malignancies, a phase II study in children with recurrent or refractory brain tumors was performed.

PROCEDURE

Patients ≤ 21 years of age at diagnosis with a recurrent, progressive, or refractory primary CNS malignancy and measurable disease, were eligible. Patients enrolled into four strata: ependymoma (N = 4), high-grade glioma (HGG) (N = 6), brainstem glioma (BSG) (N = 13), and primitive neuroectodermal tumor (PNET) (N = 8). Oral topotecan was administered once daily at a dose of 0.8 mg/m(2)/day for 21 consecutive days repeated every 28 days. Response and toxicity profiles were evaluated.

RESULTS

Twenty-six patients were evaluable (median age 9.2 years; 10 males). Two objective responses were observed in PNET patients with disseminated tumor at study entry. These two patients remain alive and in remission 7 and 9.5 years off study. Four other patients (two BSG, one PNET, and one HGG) had stable disease (median 4.6 months). The most common toxicities were hematologic.

CONCLUSIONS

Daily oral topotecan at a dose of 0.8 mg/m(2)/day can be safely administered to children with recurrent or refractory brain tumors. This regimen identified activity in recurrent PNET. The prolonged progression free survival (PFS) in two PNET patients justifies consideration of this regimen in more advanced clinical trials.

Medulloblastoma with extensive nodularity undergoing post-therapeutic maturation to a gangliocytoma: a case report and literature review

We present a report of a 12-year-old boy diagnosed with medulloblastoma at 22 months of age. A gross total resection was performed followed by adjuvant systemic chemotherapy due to his young age; however, the tumor recurred locally in the posterior fossa 7 months later. The recurrent tumor was excised and he received craniospinal radiation with a boost given to the posterior fossa followed by high-dose chemotherapy. He remained disease free for approximately 10 years without major neurologic deficit and only mild cognitive impairment. A routine follow-up MRI of the brain revealed an enhancing mass. The patient underwent surgical debulking and pathological examination revealed no residual immature medulloblastoma cells but instead mature ganglion cells, consistent with a gangliocytoma. The apparent maturation of primitive medulloblastoma cells is a rare phenomenon, which may have ensued from the long-term effects of adjuvant therapies inducing advanced cellular maturation.

Primary cerebral neuroblastoma: a case report and review

Primitive neuroepithelial tumors are the least common among supratentorial tumors in children. They pose great diagnostic difficulty, preoperatively as well as pathologically. Being quite rare, cerebral neuroblastomas are accepted as a distinct pathological entity, which differs from other neuroectodermal tumors, although clinically, radiologically, and morphologically at operation they are indistinguishable. Also differentiation between primary cerebral neuroblastoma and the other primitive neuroectodermal tumors may be difficult on light microscopy and be misleading. A 9-year-old girl with primary cerebral neuroblastoma who was initially misdiagnosed is reported. The other cases from the literature are reviewed and the nature of this rare tumor and its differential diagnosis is discussed.

Medulloblastomas with extensive posttherapy neuronal maturation. Report of two cases

The authors report on two patients with classic medulloblastoma, each of whom underwent extensive therapy-associated neuronal maturation. The first patient presented at 3 months of age with hydrocephalus caused by a 5-cm tumor in the cerebellar vermis. He underwent a gross-total resection of a desmoplastic medulloblastoma. No mature elements were identified. Despite adjuvant chemotherapy, a 1.5-cm recurrent tumor developed 6 months later. Sections from the subtotally resected tumor demonstrated exclusively mature neuronal elements, ranging from neurocytes to ganglion cells. Four months later, a second recurrent tumor was resected. The specimen collected this time demonstrated classic medulloblastoma morphological characteristics. The patient was subsequently treated with radiation therapy, which seemed to have an effect; however, the tumor eventually progressed and the patient died. The second patient presented at 3 years of age with a midline medulloblastoma and was treated with subtotal resection, radiation therapy, and chemotherapy. Although the tumor remained stable on radiographic imaging, a second resection was performed 8 years later to alleviate hydrocephalus. Histological examination revealed predominantly small mature neurons with scattered ganglion cells and extensive calcification. No adjuvant therapy was given and the patient is alive and well as of his last follow-up examination. The mature neuronal neoplasms resected in both patients demonstrated negligible proliferative indices and stained appropriately with neuronal immunohistochemical markers. The smaller neuronal population resembled those of a central neurocytoma and medullocytoma/cerebellar neurocytoma. Analogous to neuroblastoma, our cases suggest that adjuvant therapy can induce extensive or complete neuronal maturation in medulloblastoma. Additional cases must be studied to determine the prognostic significance of this rare phenomenon.

Cerebellar neuroblastoma in an infant

A cerebellar neoplasm in an 8-month-old boy is reported. While this tumour was composed of small cells and had regions resembling desmoplastic medulloblastoma, it showed ultrastructural neuronal characteristics including bundles of microtubules in the cell processes, numerous synaptic vesicles, and occasional abortive or complete synapses. These characteristic features warranted the diagnosis of a neuroblastoma of the cerebellum. The nature of this rare intraparenchymal tumour in infants is also briefly discussed.

Medulloblastoma with extensive nodularity: a variant with favorable prognosis

OBJECT

Some medulloblastomas (MBs) are characterized by extreme nodularity and intranodular nuclear uniformity in a fine fibrillary background. These lesions have also been designated as "cerebellar neuroblastoma." Although numerous reports have been published in which their morphological features have been investigated, only a few studies have been focused on their neuroradiological appearance, biological behavior, and response to therapy. The goal of this study was to gather more information about these lesions.

METHODS

The authors present 11 cases of MB with extensive nodularity. Five patients were boys and six were girls; all but one were 24 months of age or younger at diagnosis. Magnetic resonance imaging disclosed a peculiar grapelike architecture in eight cases. Surgical tumor removal was complete in nine cases and partial in one. In the other case a biopsy sample of the tumor was obtained after a preoperative course of chemotherapy. After surgery, two children were treated with radiotherapy alone and one with craniospinal irradiation followed by systemic chemotherapy. Eight patients were treated with chemotherapy only. All the patients in the study are presently alive with a median follow up of 66 months. Eight patients (73%) are in complete remission at 35 to 156 months. Three patients treated with chemotherapy alone postsurgery relapsed; however, all underwent successful retreatment (two with craniospinal irradiation and one with further surgery plus high-dose chemotherapy) and are in complete remission. A review of the literature revealed that patients in 11 of 12 reported cases were younger than 3 years of age and that seven of eight in whom follow-up information was available were alive and well, with survival times ranging from 6 to 84 months.

CONCLUSIONS

Medulloblastomas with extensive nodularity represent a variant that is characterized by: 1) occurrence in very young children; 2) a peculiar grapelike appearance on neuroimaging; and 3) an apparently favorable outcome.

Anaplastic gangliocytoma with eosinophilic cytoplasmic granules in a cow

In a 3-year-old Holstein cow, a tumor mass replaced the left olfactory bulb. The tumor was highly or moderately cellular, and consisted of tumor cells showing pleomorphism and anaplasia, sometimes with intracytoplasmic granules. The tumor showed weak reactivity for neurofilaments (NF) in most cells with distinct staining in a minority, and it was extremely rare to see neoplastic cells with positivity for glial fibrillary acidic protein (GFAP). The neoplastic cells displayed some ultrastructural features reminiscent of ganglionic cells, and the cytoplasmic granularity was due to the presence of numerous lysosomes. This tumor expressing both NF and GFAP may be histogenetically related to brain tumors of pluripotential cell origin in calves.

Multifocal neurocytoma/gangliocytoma with extensive leptomeningeal dissemination in the brain and spinal cord

This report describes an unusual neuronal tumor detected at the autopsy of a 17-year-old boy. The tumor showed multifocal parenchymal involvement with extensive leptomeningeal dissemination. The intraparenchymal lesions were small and located mainly in the subpial region of the cerebrum, cerebellum and spinal cord. Leptomeningeal dissemination was particularly pronounced at the base of the brain and around the spinal cord and presumably took place during the relatively long clinical course. The tumor was composed of small round cells and ganglion-cell-like cells. Only neuronal differentiation, as represented by immunostaining with antisynaptophysin antibody and the presence of dense-core vesicles in the cytoplasm, was evident in both types of cells. The small round cells appeared to exhibit the features of small, relatively mature neurons rather than those of neuroblasts. Moreover, our results suggested maturation from small round cells to ganglion-cell-like cells. The tumor appears to be related to gangliogliomas or dysembryoplastic neuroepithelial tumors, and we have chosen the term neurocytoma/gangliocytoma for the unusual lesion.

Inhibition of proliferation and induction of differentiation in medulloblastoma- and astrocytoma-derived cell lines with phenylacetate

The authors investigated the effects of a nontoxic differentiation inducer, phenylacetate (PA), on neuroectodermal tumor-derived cell lines. Treatment of medulloblastoma (Daoy and D283 MED) and glioma (U-251MG, C6, and RG2) cell lines resulted in a dose-dependent decline in DNA synthesis and cell proliferation, associated with accumulation in the G0/G1 phase of the cell cycle. Phenylacetate decreased transforming growth factor (TGF)-beta 2 production by medulloblastoma Daoy cells. Neutralizing antibodies against either TGF beta 2 or TGF beta 1 failed to block the growth arrest observed. This suggests that, unlike other differentiation agents, such as retinoic acid, the effect of PA on medulloblastoma proliferation is not mediated by a TGF beta pathway. In addition to cytostasis, PA induced marked morphological changes in U-251MG and C6 glioma cells associated with increased abundance of glial fibrillary acidic protein-positive processes. Although the morphology of PA-treated medulloblastoma cells was not significantly altered, the D283 MED cells exhibited increased expression of neurofilament proteins and Hu antigen, indicative of differentiation along a neuronal pathway. The effects of PA on the medulloblastoma cell lines were compared to its effects on the human neuroblastoma cell line BE(2)C, which is capable of a bidirectional differentiation toward a neuronal or a glial/schwann cell pathway. In BE(2)C cells, PA induced differentiation toward a schwann/glial cell-like phenotype, suggesting that the choice of differentiation pathway is cell type and agent specific. These in vitro antiproliferative and differentiation inducing effects of PA suggest that this agent warrants further evaluation as a potential therapeutic modality for the treatment of medulloblastoma and malignant glioma in humans.

Pigmented intracerebral neuroepithelial cyst: report of a case

A 35-year-old man with seizure disorder was found to have a parietal lobe neuroepithelial cyst. The lining of the cyst was made up of ependymal cells containing neuromelanin, which was confirmed ultrastructurally. This appears to be the first report of a pigmented neuroepithelial cyst in the brain parenchyma.

Cerebral neurocytoma. A new subset of benign neuronal tumors of the cerebrum

Three cases of patients with unusual neuronal tumors in the cerebral hemisphere are reported. All were associated with long-standing epileptic seizures. Computed tomography disclosed low-density lesions without contrast enhancement, which were interpreted as either arachnoid cysts or a cerebral infarction at initial diagnosis. Magnetic resonance imaging scans, however, revealed the lesions to be solid tumors. At surgery, the tumors were found to be relatively well demarcated, soft, and gelatinous. Histologically, all tumors were composed of small uniform stellate cells, which proliferated in a loose myxoid fibrillary matrix and resembled either oligodendroglial or astrocytic tumors. Ultrastructurally, however, all tumors showed neuronal differentiation, including numerous clear and occasional dense-core vesicles, microtubules, and a number of synapses. A review of the literature uncovered no other such cases, and therefore it was decided to classify these tumors as a distinct group of benign neuronal tumors, designated as "cerebral" neurocytoma compared with "intraventricular" neurocytoma. Related nosologic problems of neuronal tumors of the central nervous system and their possible histogenesis are also discussed.

Dominant and Recessive Molecular Changes in Neuroblastomas

Of all human tumors, neuroblastomas bear the most prominent genetic changes. Amplifications and deletions of chromosomal DNA can be identified by light microscopy on chromosomal spreads of neuroblastoma cells with remarkable frequency and consistency. Consequently, extensive studies have been undertaken to elucidate the molecular basis of these cytogenetic changes. A rich body of information has accumulated on the role played by dominant oncogenes and recessive tumor suppressor genes in the pathogenesis of this disease. Most notably, it was found that amplification of N-myc is responsible for the presence of double minutes and homogeneously staining regions in neuroblastoma chromosomes. It has also been discovered that N-myc amplification is a prognostic sign of malignancy. More recently, recessive genetic alterations in neuroblastoma, such as deletion of putative tumor-suppressing genes have received increasing attention, and considerable efforts are being made to identify such genetic elements. Finally, the susceptibility of neuroblastoma cells to differentiating stimuli has made them a popular in vitro system for neurobiological and pharmacological research. The need for suitable in vivo systems has spurred the development of several animal models employing tumor viruses and transgenic technologies.

Immunohistochemistry of primitive neuroectodermal tumors in infants with special emphasis on cytokeratin expression

Eleven primitive neuroectodermal tumor (PNET) biopsies from infants under the age of 3 years were studied for the presence of various differentiation markers for neuroectodermal stem cells. Special emphasis was placed on the expression of cytokeratin proteins. The tumor cells expressed different cytokeratin proteins (CK8, CK13, CK18, CK19, KL1, AE1/AE3, MNF16) in 3 of 11 cases. These cases were furthermore characterized by a strong expression of glial fibrillary acidic protein, S-100 protein and vimentin. Vimentin and cytokeratin proteins were co-expressed; cross-reactivity between these two intermediate filaments could be excluded by immunoblotting. It is noteworthy that the three positive tumors were all from infants in their 1st year. We assume that PNETs in early infancy are characterized by a particularly wide range of differentiation patterns. The presence of cytokeratin proteins in these cases seems to be associated with the expression of vimentin and must be regarded as an indicator of an early developmental stage of the tumor cells.

Human melanoma-associated antigen expression on human neuroblastoma cells: effects of differentiation inducers

We have described two human melanoma-associated antigens (HMAA), recognized by the murine monoclonal antibodies LS62 and LS109. LS62 recognizes the neuroglandular antigen (NGA), which is overexpressed in neoplastic melanocytes as well as in several tissues of neuroectodermal origin. These antibodies were used to screen six neuroblastoma cell lines and one neuroepithelioma cell line. A melanoma cell line, G361, known to express the two antigens, was used as the positive control. Variable expression of the two antigens was detected in neuroblastoma cells. The surface expression of NGA and of the LS109 antigen was modulated in parallel with the morphological differentiation induced by retinoic acid, 5-bromodeoxyuridine, or cyclic AMP analog/activators. The modulation of the expression of the two HMAA was detected in G361 melanoma cells and in one of the neuroblastoma cell lines, SK-N-SH. These results suggest altered expression of both antigens during melanoma and neuroblastoma cell differentiation in culture.

Melanocytic differentiation of human neuroblastoma: expression of a human melanosome-associated antigen

Five human neuroblastoma cell lines were examined for expression of a human melanosome-associated antigen (HMSA). Only cell line SK-N-SH reacted with a monoclonal antibody, HMSA-2, shown to recognize melanosomal glycoproteins. To further characterize the melanocytic lineages of SK-N-SH, three morphologically distinct clones designated SK-N-SH-N (neuroblast type), SK-N-SH-F (fibroblast type), and SK-N-SH-EP (epithelial type) were established by colony formation cloning. By fluorescence-activated cell sorter analysis and tyrosinase assay, we found that only SK-N-SH-EP and SK-N-SH-F reacted with HMSA-2 and had tyrosinase activity. These results suggest that epithelial-type and fibroblast-type cells appear to possess the melanocytic potential, but not neuroblast-type cells. Furthermore, SK-N-SH-EP was found to spontaneously convert to neuroblast-type or fibroblast-type cells, whereas SK-N-SH-N and SK-N-SH-F clones have remained morphologically stable. Our results suggest that at least one neuroblastoma cell line, SK-N-SH, may be an excellent model for investigating clonal maturation and the melanocytic differentiation of neuroblastoma.

Primary cerebral ganglioneurocytoma in an adult

A case of an unusual cerebral neuronal tumor in a 37-year-old woman is described. A clearly marginated tumor, which was found to occupy the septum pellucidum, genu of the corpus callosum, and right frontal lobe, was composed of ganglionic and small round cells. These two populations of neoplastic cells were both interpreted as being in the advanced stages of neuronal maturation, and the authors thus designated this tumor as a "ganglioneurocytoma." Related nosologic problems on central neuronal tumors and their possible histogenesis are also discussed.

Desmoplastic cerebral astrocytoma of infancy. Light microscopy, immunocytochemistry, and ultrastructure

The first detailed ultrastructural study of a superficial desmoplastic cerebral astrocytoma of infancy is reported. This is a neoplasm which mimics a mesenchymal tumor, originally described in 1984 under the name of "superficial cerebral astrocytoma attached to dura." This tumor, which is believed to have a good prognosis, was resected from the frontoparietal region of a 6.5-month-old girl, in whom it had presented as a large densely enhancing vascular and cystic mass. The ultrastructure of the tumor appeared to be distinctive, characterized by the absence of neuronal elements, and the presence of large amounts of redundant and sometimes extensively duplicated basal laminal material and collagen between nonpleomorphic and nonlipidized astrocytes, corresponding to the reticulin fibers seen by light microscopic analysis between the S-100 protein and glial fibrillary acidic protein (GFAP)-positive cells. The features of the tumor, its differential diagnosis, and its relationship to other pediatric supratentorial tumors are discussed.

Melanotic paraganglioma of the orbit: a case report

A paraganglioma of the orbit in a 21-year-old woman is presented, containing oculo-cutaneous melanin in many tumor cells, occasionally adjacent to neurosecretory granules, and in macrophages. This tumor expands the list of neuroectodermal tumors with potential melaninization.

Melanotic ganglioglioma of the pineal region

A melanotic ganglioglioma was biopsied in the pineal region of a 12-month-old girl who preoperatively underwent a ventriculo-peritoneal shunt for hydrocephalus and postoperatively received radiotherapy. The tumor was subtotally excised when the girl was 7 years and 4 months of age. Histologically, it demonstrated mature neurons in disorganized clusters and in well-differentiated cerebrum-like tissue, rare binucleated neurons, glia similar to normal gray matter, and bands of fibrous tissue containing heavily pigmented cells. Ultrastructurally, melanosomes of stages I to IV were identified in the pigmented cells. An origin involving retinal differentiation of the primitive pineal gland was not supported; the tumor was negative for both retinal S-antigen (MAbA9-C6) and cellular retinal-binding protein (CRALBP). This report demonstrates the ability of a cerebral neoplasm to contain neurons, glia, and melanin-containing cells; all of which are neuroectodermally derived.

Pigmented esthesioneuroblastoma showing dual differentiation following transplantation in nude mice. An immunohistochemical, electron microscopical, and cytogenetic analysis

Esthesioneuroblastoma (ESTH) is a neuroepithelial-cell-derived neoplasm of the olfactory mucosa composed of homogeneous small round cells which contain neurosecretory granules. Melanin has been detected in such tumours only occasionally. Here we describe a new case of ESTH with divergent differentiation. The primary neoplasm was found in a 67 year-old female, involving the left nasal and maxillary sinus; she died of cerebral metastasis ten months after diagnosis. Histologically only small round cells were seen, with S-100 and NSE positivity. Electron microscopy revealed neurosecretory granules and filaments, as well as the occasional presence of melanosomes. A nude mice xenograft line has been established, and is presently in its ninth transfer. Two cell types are present: small round-to-spindle shaped cells with neural features, and large epithelial-like ones. Both immunohistochemistry and electron microscopy confirm this dual differentiation, with the presence of membrane-bound dense-core neural secretion, as well as melanosomes of neuroectodermal origin. Additionally, an in vitro cell line has been established. Cytogenetic analysis confirmed the presence of both malignant human melanoma patterns; non-random abnormalities in chromosomes 1 and 6, extra copies of chromosome 7. Duplication of the long arm of chromosome 14, as seen in olfactory neuroblastoma, is also seen.

Intraventricular neurocytoma: clinicopathological features of six cases

The clinical and pathological features of six patients with so-called "intraventricular oligodendroglioma" are reported. The tumor had no predilection for sex, and the patients' age at diagnosis ranged from 15 to 39 years. The lesions were located in the lateral and/or third ventricles. Total removal of the tumor was performed in three patients, and the remaining three underwent partial resection. Postoperative irradiation was given to five patients. A follow-up study revealed that five patients were free of recurrent tumor at 15 to 227 months after treatment, and one was alive with disease 25 months after surgery. Histologically, all tumors were composed of small uniform cells, with perinuclear halos and regular round nuclei. Tumor cells were sometimes arranged around nucleus-free fibrillary zones. Mitoses were infrequent. Ultrastructurally, neoplastic cells had round nuclei with dispersed heterochromatin and organelle-sparse cytoplasm containing occasional microtubules, 20 to 25 nm in diameter, and scattered dense-core vesicles, 100 to 200 nm in diameter. Cell processes containing dense-core and clear vesicles were frequently present. Thus, these neoplasms should be considered neuronal in origin, and should be classified as "intraventricular neurocytomas."

Bilateral adrenal ganglioneuroblastoma with neuromelanin. Clinical and pathologic observations

A case of bilateral adrenal ganglioneuroblastoma in an adolescent boy is described. The clinical evolution was remarkable for its quiescent course, despite unfavorable prognostic indicators that included: intraabdominal primary site, large tumors on both sides of the midline, and "unfavorable" pathologic subtype. There was no family history of neuroblastomas. Production of neuromelanin was manifested by this unusual tumor. A review of published cases of multifocal neuroblastomas suggests that these tumors follow an uncommon natural history, at variance with the expected behavior of the usual unicentric and sporadic type of neuroblastoma.

Posterior fossa neuroblastoma occurring in an elderly man

A case of a neuroblastoma occurring in the cerebellum of a 73-year-old man is reported. The patient presented with progressive truncal ataxia and was found to have an enhancing tumor mass in the cerebellar vermis. By light microscopy, the tumor was a small cell neoplasm and was similar to medulloblastoma, with areas showing structures suggestive of Homer-Wright pseudorosettes. By electron microscopy and immunoperoxidase techniques, however, the tumor showed convincing evidence of neuronal differentiation. The absence of previous reports of this tumor in the posterior fossa of adults suggests that immunoperoxidase techniques and/or electron microscopy of such small cell tumors may be required for accurate diagnosis.