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2-Methoxyestradiol interferes with NF kappa B transcriptional activity in primitive neuroectodermal brain tumors: implications for management.

Medulloblastoma (MB) is a primitive neuroectodermal tumor (PNET) of the central nervous system (CNS) and the most common malignant primary brain tumor in children. Currently, poor risk and recurrent MB patients are treated with cytotoxic chemotherapy alone or in combination with surgery and irradiation. In order to improve on therapeutic outcome and reduce toxicity of current treatment strategies, new and novel therapeutic agents are needed for MB patients. To that purpose, we have examined the effect of 2-methoxyestradiol (2-ME), an endogenous non-toxic estrogenic metabolite on the growth of three medulloblastoma cell lines (DAOY, D341 and D283); and two high-grade anaplastic astrocytoma/glioblastoma cell lines, U-87MG and T-98-G. We present evidence to show that 2-ME preferentially inhibits the growth of medulloblastoma cells significantly by blocking cell cycle progression predominantly in G(2)/M phase. 2-ME treatment results in phosphorylation of cdc25C without any significant alterations in the expression of cyclin B1 or p34cdc2. In addition, we observed a decrease in the levels of 14-3-3 proteins following treatment with 2-ME. Furthermore, 2-ME-mediated growth inhibition is accompanied by induction of apoptosis as evidenced by morphological alterations and DNA fragmentation analysis. Of interest is the finding that 2-ME induced apoptosis is not mediated through alterations in the expression of p53 or Bax and that transcriptional activity of NF kappa B and DNA binding activity is reduced indicating that 2-ME disrupts the NF kappa B signaling pathway. These results suggest that 2-ME may prove to be a useful therapeutic agent in the treatment of PNET brain tumors such as medulloblastoma. In addition, as 2-ME inhibits growth predominantly through G(2)/M block, it may enhance the effectiveness of radiation therapy.

2-Methoxyestradiol↗

Neuroectodermal and neuroendocrine tumors principally seen in children.

Neuroectodermal tumors comprise a large proportion of childhood neoplasms. Neuroblastic tumors, including neuroblastoma, ganglioneuroblastoma, and ganglioneuroma, are the most frequent extracranial solid cancers of childhood, occurring primarily in infants and toddlers. Primitive neuroectodermal tumors, including Ewing sarcoma and peripheral neuroepitheliomas, occur most frequently in older children and adolescents, and as pediatric sarcomas are second in frequency only to rhabdomyosarcomas. Rarer neuroectodermal tumors include desmoplastic small cell tumors, esthesioneuroblastomas, and melanotic neuroectodermal tumors, the first two entities occurring as rather site-specific lesions in the abdomen and nose, respectively. Diagnosis can be difficult due to the undifferentiated nature of many of these cancers, but ancillary studies, including electron microscopy, immunohistochemistry, cytogenetics, and molecular genetics, enhance their recognition. The molecular nature of childhood neuroectodermal tumors is as diverse as their histology, ranging from the fusion genes characterizing the Ewing sarcoma family of tumors to the proto-oncogene amplification seen in aggressive neuroblastomas.

Adolescent↗

The potential for complete and durable response in nonglial primary brain tumors in children and young adults with enhanced chemotherapy delivery.

PURPOSE: Radiographic tumor response and survival were evaluated in the pediatric and young adult population with germ cell tumor, primary CNS lymphoma, or primitive neuroectodermal tumor receiving intra-arterial carboplatin- or methotrexate-based chemotherapy with osmotic blood-brain barrier disruption (BBBD). PATIENTS AND METHODS: Thirty-four patients with histologically confirmed germ cell tumor (n = 9), primary CNS lymphoma (n = 9), or primitive neuroectodermal tumor (n = 16) were treated at the Oregon Health Sciences University from August 1981 through April 1995. Ages ranged from 1 to 30 years (mean, 18 years). Prior treatments included cranial radiation (n = 10) and chemotherapy (n = 18). All patients underwent extensive baseline neuropsychological evaluation and follow-up evaluation upon completion of the protocol, except for two patients who declined follow-up assessment. RESULTS: Six hundred and forty-five BBBD procedures were performed with no mortality. Significant complications included one episode of tonsillar herniation with no neurologic sequelae, 4% incidence of seizures, and 3% incidence of sepsis or granulocytopenic fever. Ototoxicity was seen in 61% of patients who received carboplatin chemotherapy. Eighty-two percent of the patients had an objective response to treatment, including 62% with complete response and 20% with partial response. For most patients, cognitive functioning was maintained or improved at follow-up; this pattern was statistically significant. Three of the test scores for the seven patients who did not receive radiation therapy showed a cognitive decline of at least one standard deviation. Among the nine patients who received radiation therapy before or after BBBD chemotherapy, 11 test scores showed a decline in cognitive function at one standard deviation or more. DISCUSSION: Durable responses were seen in patients with germ cell tumor and primary CNS lymphoma when treated with BBBD. Primitive neuroectodermal tumor requires post-chemotherapy radiotherapy for a durable response to be attained. Ototoxicity was a major form of toxicity in the patients who received carboplatin, but with the recent introduction of sodium thiosulfate, this problem has been markedly alleviated. Favorable cognitive outcomes appeared more likely for patients treated solely with BBBD chemotherapy and not with radiotherapy. Trends in the results for this sample are similar to those of previous research showing that radiotherapy is associated with cognitive decline. Current alternatives to enhanced drug delivery after BBBD include bone marrow transplantation; however, the increment in drug delivery is less, the number of courses is limited, and the morbidity and mortality are greater for bone marrow transplant than for BBBD. The current results suggest that in future trials, irradiation may not be needed in lymphoma and may not be necessary in some CNS germ cell tumors and that more focal radiotherapy should be further assessed in localized primitive neuroectodermal tumors.

Adolescent↗

Relation between maternal diet and subsequent primitive neuroectodermal brain tumors in young children.

BACKGROUND: It has been hypothesized that a high dietary intake of nitrosamines and their precursors, nitrites and nitrates, is a risk factor for brain tumors. Vitamins C and E inhibit the formation of nitrosamines and thus may be protective. METHODS: We conducted a case-control study of maternal diet and the risk of primitive neuroectodermal tumors of the brain in children. The case patients were under the age of six years at diagnosis in 1986 to 1989. The controls were selected by random-digit telephone dialing and were matched for age and race to 166 case patients. Telephone interviews with the mothers included questions on the frequency of consumption of alcohol, vitamin and mineral supplements, and 53 foods during pregnancy. RESULTS: Significant protective trends were observed for vegetables (odds ratio for the highest quartile group for intake relative to the lowest, 0.37; P for trend = 0.005), fruits and fruit juices (odds ratio, 0.28; P = 0.003), vitamin A (odds ratio, 0.59; P = 0.03), vitamin C (odds ratio, 0.42; P = 0.009), nitrate (odds ratio, 0.44; P = 0.002), and folate (odds ratio, 0.38; P = 0.005). A nonsignificant trend of increasing risk was observed for nitrosamine (odds ratio, 1.65; P = 0.15). The use of iron (odds ratio, 0.43; P = 0.004), calcium (odds ratio, 0.42; P = 0.05), and vitamin C (odds ratio, 0.35; P = 0.04) supplements at any time during the pregnancy and the use of multivitamins during the first six weeks (odds ratio, 0.56; P = 0.02) were associated with decreased risk. In multivariate analyses, folate, early multivitamin use, and iron supplements generally remained protective. CONCLUSIONS: These results do not support the hypothesis that nitrosamines have a role in the development of primitive neuroectodermal tumors in young children, but they do suggest that certain other aspects of maternal diet can influence the risk.

Astrocytoma↗

Successful treatment of primitive neuroectodermal tumor-associated microangiopathy with multiple bone metastases.

We report here a 16-year-old male with primitive neuroectodermal tumor (PNET)-associated probable microangiopathy with multiple bone metastases. Laboratory findings excluded the possibility of amegakaryocytic or immune thrombocytopenia and/or disseminated intravascular coagulation. He was first treated with plasma-exchange (PE), followed by platelet transfusions, steroid pulse therapy and combined chemotherapy. PE and steroid pulse therapy reduced his plasma CRP level. Combined chemotherapy drastically increased his platelet count until it had almost normalized without further transfusion. The plasma level of von Willebrand factor-cleaving protease (ADAMTS13) activity measured before PE was not severely deficient (48% of normal) and an unusually large von Willebrand factor multimer (UL-VWFM) was detected. We consider that this therapeutic strategy has the following benefits: (1) reduction of plasma levels of factors that are harmful to both platelet activation and endothelial cell injury; and (2) the safe transfusion of platelet concentrate in thrombotic microangiopathy. This strategy should be confirmed in further cases.

Adolescent↗

High microvessel density in primitive neuroectodermal brain tumors of childhood.

Microvessel density (MVD), a measure of tumor angiogenesis, has been shown to correlate significantly with overall and progression-free survival outcomes in various cancers including astrocytic brain tumors. To assess if the MVD is an independent prognostic factor in primitive neuroectodermal tumors (PNET) of the central nervous system, formalin-fixed paraffin-embedded tumor sections of 78 children with PNET were studied by CD34 immunohistochemistry to highlight endothelial cells. Microvessel density was determined in the most active area of neovascularization according to well-established methods. While it was shown that MVD showed considerable inter-tumor variability (median 75; range 20-345 microvessels per 0.7 mm2 field), no significant associations were found between MVD and metastasis or survival outcomes. We conclude that many PNETs are highly vascular CNS tumors, indicating potent angiogenic activity. Therefore, these tumors would be good candidates for antiangiogenic strategies. However, MVD determined in the most active area of neovascularization is not a predictor of metastatic potential or survival outcomes in childhood PNET.

Adolescent↗

Atypical teratoid/rhabdoid tumor of the brain: cytopathologic characteristics and differential diagnosis.

BACKGROUND: Atypical teratoid/rhabdoid tumor (AT/RT) is a highly aggressive neoplasm with a unique cytogenetic profile. Although the clinicopathologic and radiologic features of AT/RT have been described previously, to the authors' knowledge the cytomorphologic profile of this tumor has not been studied well. METHODS: Nine samples of AT/RT from 8 patients were analyzed from the pathology files of 2 large institutions in a 10-year period (1993-2002). Material consisted of slides made from scraping and smearing (SS) or squash preparation (SP) of the tissue cores (six slides), fine-needle aspiration (FNA) (two slides), and cerebrospinal fluid (one slide). Smears were stained with Diff-Quik, Papanicolaou, and hematoxylin and eosin stains. RESULTS: There were 4 males and 4 females who ranged in age from 1-16 years (mean age, 7.1 years). Cytomorphologic features consisted of hypercellularity (eight of eight tumors); predominantly large tissue fragments with tumor cells surrounding proliferating capillaries depicting a "papillary-like" appearance (five of eight tumors); large, round, "plasmacytoid" cells and characteristic "rhabdoid" cells (i.e., intermediate-sized cells with granular to fibrillary, brightly eosinophilic cytoplasm with or without globoid "inclusions"; large, eccentrically located, round-to-reniform nuclei with single prominent nucleoli; eight of eight tumors); small, round, primitive "neuronal-appearing" cells with a high nuclear to cytoplasmic ratio (five of eight patients); and bizarre, multinucleated giant cells (two of eight tumors). Also seen were numerous apoptotic bodies, mitoses, and significant necrosis (seven of eight tumors), and prominent dystrophic calcification (four of eight tumors). CONCLUSIONS: AT/RT is extremely rare. Cytologic examination by SS, SP, or FNA offers a useful alternative to frozen section during intraoperative consultation. Cytomorphologic features are unique and lead to an accurate diagnosis in the right clinicoradiologic context. The differential diagnosis includes medulloblastoma (in cerebellar tumors), primitive neuroectodermal tumor (in suprasellar tumors), choroid plexus carcinoma, and malignant glioma.

Adolescent↗

Identical characteristics of the patient populations with pineal region tumors in Japan and in Korea and therapeutic modalities.

The therapeutic modalities used for tumors of the pineal region in Western countries differ from those in Japan, mainly because of the different patient populations. An extensive survey was conducted to delineate the racial differences in Japan and in Korea in the epidemiology and recent therapeutic modalities for this tumor group. Among the members of International Society for Pediatric Neurosurgery (ISPN), 15 from Japan and 5 from Korea reported their recent findings in 118 (1-25 years of age, mean 7.38-year period) and 125 (1-12 years of age, mean 6.69-year period) histologically verified cases, respectively. The patient populations in the two countries were found to be almost identical, with an extremely high incidence of germ cell tumors representing 71.2% (in Japan) and 80.0% (in Korea) of all pineal region tumors and neuroectodermal tumors representing only 15.2% and 16.8%, respectively. The most common type of pineal region tumor was germinoma (46.6% in Japan and 47.2% in Korea). The majority of tumors were radio- and/or chemosensitive, and adjuvant therapy rather than extensive surgery played the major role in the treatment in both countries. Radical resection of the tumor was recommended as the initial procedure by only 22.2% of neurosurgeons in Japan and 16.6% in Korea. Biopsy was recommended by 38.9% and 50.0%, and radiation therapy by 38.9% and 37.5%, respectively. A minimally invasive procedure, by either a neuroendoscopic (33.3% of biopsies in Japan) or a stereotactic approach (33.3% of biopsies in Korea), was considered to be appropriate as the initial procedure. The study disclosed the almost identical epidemiology of this brain tumor in Japan and in Korea and clarified the consequent therapeutic modalities. The authors emphasize that minimally invasive tissue diagnosis with or without tumor debulking should be considered as the initial step for the treatment planning of the pineal region tumor, followed by the most commonly indicated major procedures, including radiation therapy, chemotherapy and/or radical resection with various methodologies.

Adolescent↗

Activation of TRK genes in Ewing's sarcoma. Trk A receptor expression linked to neural differentiation.

Trk receptors have been identified by immunohistochemical methods in primitive neuroectodermal tumor (PNET)/Ewing's sarcoma (ES). However, the presence of different members of the Trk family of receptors in PNET/ES has not been specified. We have examined whether Trk A, B, and C receptors are specifically expressed in ES both with and without features of neural differentiation. Ten ES tumors (five primary tumors of bone and five extraosseous tumors transplanted into nude mice) were investigated for expression of Trk receptors by immunohistochemistry and reverse transcription-polymerase chain reaction. One primary ES and the five grafted ES tumors exhibited signs of neural differentiation; the remaining four primaries were undifferentiated ES. Other tumor types were analyzed as controls; they included three neuroblastomas (NB), two lymphomas, and single cases of pheochromocytoma (PHEO), schwannoma (SCHW), osteosarcoma, and carcinoma of breast, colon, and kidney. Trk receptors were detected in paraffin-embedded tumor tissue sections by means of a pan-Trk polyclonal antibody raised against the 14 carboxy-terminal residues of gp140trk, and trk A, B, and C transcripts were specifically detected by polymerase chain reaction-based amplification on cDNAs derived from tumor RNA with MuLV reverse transcriptase. Reactivity to the pan-Trk antibody was exhibited by six ES tumors, the three NBs, and the single PHEO and SCHW cases; immunoreactivity was restricted to differentiated tumors, in the case of ES. Tumor types positive for immunostaining were also distinguished by containing transcripts of TRK genes. However, the trk A, B, and C expression pattern of ES differed from that of NBs, PHEO, and SCHW. Transcripts of trk A, B, and C were detected in seven, four, and one case of ES, respectively, and in five, two, and five cases of NB, PHEO, and SCHW, respectively. Interestingly, all differentiated ES tumors contained trk A transcripts. Tumors of neuroectodermal phenotype and/or derivation were thus characterized by a distinct consensus expression pattern: trk A+/B-/C+ for differentiated ES and trk A+/B-/C+ for NB-PHEO-SCHW. These results indicate that the TRK gene family is frequently activated in ES; they also suggest that Trk A receptor is a feature of ES with neural differentiation, whereas Trk B and C receptors seem to be present in undifferentiated ES.

Animals↗

Malignant peripheral primitive neuroectodermal tumor-peripheral neuroepithelioma of the head and neck: a clinicopathologic study of five cases and review of the literature.

BACKGROUND: The term primitive neuroectodermal tumor (PNET) encompasses a number of neoplasms of common neuroectodermal origin, but of variable clinical, histopathologic, ultrastructural, and molecular characteristics. Here, we focus on one particular member of the PNET family, the malignant peripheral PNET (pPNET) or peripheral neuroepithelioma of head and neck. METHODS: Five patients diagnosed with malignant pPNET-peripheral neuroepithelioma of head and neck were included in the study. All existing literature was reviewed. RESULTS: The diagnosis of malignant pPNET-peripheral neuroepithelioma of the head and neck was confirmed in all five cases. All patients are alive after treatment with a combination of therapeutic modalities; only one patient had metastatic disease develop. A literature review revealed another 38 reported cases. CONCLUSIONS: Malignant pPNET-peripheral neuroepithelioma should be included in the differential diagnosis of small, round, blue cell tumors of head and neck. A combination of multiple diagnostic modalities is essential for correct diagnosis, and multimodality treatment offers the best outcome.

12E7 Antigen↗

Insulin-like growth factor I expression by tumors of neuroectodermal origin with the t(11;22) chromosomal translocation. A potential autocrine growth factor.

Expression of insulin-like growth factor I (IGF-I) mRNA by some tumor cell lines of neuroectodermal origin has been described. To further explore the significance of IGF-I mRNA expression in these tumors, a more extensive analysis was performed. Most (9 of 10) neuroectodermal tumor cell lines with a t(11;22) translocation (primitive neuroectodermal tumor [PNET], Ewing's sarcoma, esthesioneuroblastoma) expressed IGF-I mRNA, whereas 0 of 15 cell lines without the translocation (PNET, neuroblastoma) expressed IGF-I. Furthermore, inasmuch as all neuroblastoma (12 of 12) cell lines examined expressed IGF-II RNA, the pattern of IGF expression could distinguish between these closely related tumors. CHP-100, a PNET cell line with the t(11;22) translocation, was shown to secrete both IGF-I protein and an IGF binding protein, IGFBP-2. This cell line also expressed the type I IGF receptor mRNA, and blockade of this receptor by a monoclonal antibody (alpha IR3) inhibited serum-free growth. These data demonstrate that IGF-I expression is a property of neuroectodermal tumors with a t(11;22) translocation and that interruption of an IGF-I autocrine loop inhibits the growth of these tumor cells.

Cell Division↗

Interphase cytogenetics for the detection of the t(11;22)(q24;q12) in small round cell tumors.

Among the small round cell tumors differential diagnosis is particularly difficult for their undifferentiated or primitive character. In this mixed group of tumors, only the primitive neuroectodermal tumors, which include Ewing's sarcoma (ES), show the unique and consistent feature of the (11;22)(q24;q12) translocation, which can therefore be considered a hallmark of these neoplasias. We analyzed four primitive neuroectodermal tumor cell lines, one osteosarcoma cell line, and 11 patients by fluorescent in situ hybridization with cosmid clones 23.2 and 5.8, bracketing the t(11;22) at 11q24. Metaphase spreads from tumor cell lines, and from biopsy specimens of three patients with ES were analyzed. In the remaining eight patients comprising five ES, two small cell osteosarcomas and one chronic osteomyelitis, only nuclei preparations were available for analysis. We detected the t(11;22) in interphase nuclei of the four primitive neuroectodermal tumor cell lines, of three patients in which the karyotype demonstrated the translocation and in five cases of ES in which cytogenetic analysis had not been possible. Two cases of small cell osteosarcoma and one chronic osteomyelitis were also analyzed and were both normal with respect to the t(11;22). By analyzing cell lines and small round cell tumor samples by fluorescent in situ hybridization, we established that interphase cytogenetics is a rapid alternative to chromosomal analysis for the detection of the t(11;22) and represents an invaluable tool for the differential diagnosis of small round cell tumors.

Adolescent↗

Human fetal brain antigen expression common to tumors of neuroectodermal tissue origin.

The antigenic relationship between human tumors of neuroectodermal origin and fetal brain were further investigated by characterization of two hybridoma antibodies derived from a fusion of P3-NS1/1-Ag 4-1 (NSI) myeloma cells and splenocytes hyperimmunized to second trimester human fetal brain homogenate. Monoclonal antibodies (MAs) 1H8cl 2 and 1H8cl 3 were analyzed by cell surface radioimmunoassay (CS-RIA), quantitative absorption, indirect immunofluorescence, and peroxidase-antiperoxidase (PAP) immunohistology. MA 1H8cl 3 is the more broadly reactive, binding to 9/14 glioblastoma (GBM), 2/3 neuroblastoma, 1/2 melanoma, and 1 medulloblastoma cell line(s) by CS-RIA analysis, and to 12/15 GBM, fetal brain, spleen, and liver, and adult spleen by PAP analysis. MA 1H8cl 2 is more restricted, binding to 7/14 GBM, 2/3 neuroblastoma, 1 medulloblastoma, and 2/3 fetal skin fibroblast cell line(s) by CS-RIA, and to 9/15 GBM and fetal brain and spleen by PAP analysis. Control non-central nervous system tumors and normal adult tissue including brain, thymus, lymph node, liver, kidney, lung, skin, and pancreas, were unreactive with both 1H8cl 2 and 1H8cl 3 by CS-RIA, PAP, and absorption analysis. The data presented here establish the unique nature of the detected antigenic specificities as compared to previously described oncofetal and onconeural antigens, and define two immune reagents which are operationally specific for tumors of neuroectodermal origin within the adult central nervous system.

Antibodies, Monoclonal↗

Analysis of the neurofibromatosis type 2 gene in different human tumors of neuroectodermal origin.

The autosomal dominant syndrome neurofibromatosis type 2 (NF2) is characterized by the development of bilateral vestibular schwannomas, meningiomas, ependymomas and gliomas. The NF2 gene, recently isolated from chromosome 22, is mutated in both sporadic and NF2 tumors such as schwannomas, meningiomas and ependymomas. Mutations of the gene have been described not only in the neoplasms usually associated with NF2, but also in 30% of the melanomas and 41 % of the mesotheliomas analyzed. In particular, the finding of mutations in melanomas supports the hypothesis that the NF2 gene is involved in the genesis of several tumor types that arise from the embryonic neural crest. In this study we examined, by single-strand conformational polymorphism (SSCP) analysis, 41 tumors of the central nervous system (11 schwannomas and 30 gliomas), 19 melanomas and 15 Merkel cell carcinoma specimens for mutations in the coding sequence of the NF2 gene. We found three inactivating mutations of the NF2 gene in schwannomas. No alterations of the gene were detected by SSCP analysis of the other tumors. These results confirm the role of NF2 in pathogenesis of schwannomas, but do not define its significance in the genesis of the other neuroectodermal tumors studied.

Central Nervous System Neoplasms↗

Differential telomerase expression in human primary intracranial tumors.

The telomeric repeat amplification protocol was used to detect expression of telomerase in primary intracranial tumors. Expression was confined to high-grade variants; 10 of 19 glioblastoma multiforme tumors and 5 of 5 primitive neuroectodermal tumors showed telomerase activity. Two of 8 anaplastic gliomas (1 anaplastic oligodendroglioma and 1 anaplastic oligoastrocytoma) were positive for telomerase. Of 16 meningiomas tested, only the 2 atypical variants were positive for telomerase. Two hemangiopericytomas of the central nervous system also showed expression of telomerase. Twenty-two pituitary adenomas (including 6 invasive variants), 2 low-grade gliomas, 2 ependymomas, and 8 nonneoplastic brain specimens were negative. It was concluded that expression of telomerase is found in most glioblastoma multiforme tumors; primitive neuroectodermal tumors appeared to be more uniformly positive. Expression of telomerase in atypical variants of meningioma and hemangiopericytomas of the central nervous system correlated with the potential for aggressive local growth and metastases. Despite the invasive tendency of some pituitary adenomas, telomerase was not detected in these tumors, which suggests that other pathways account for their aggressive behavior.

Adolescent↗

Leptin and apoptosis inhibitor soluble Fas antigen in the serum of patients with osteosarcoma and neuroectodermal bone tumors.

Serum contents of leptin and soluble Fas antigen were measured in 28 patients with osteosarcoma, 7 with neuroectodermal bone tumors, and 17 healthy subjects. The incidence and levels of soluble Fas antigen in patients with osteosarcoma and neuroectodermal bone tumors were higher than in healthy subjects and did not depend on sex and age in both healthy subjects and patients. Serum concentration of leptin in women was higher than in men (both in healthy controls and patients) and was lower in healthy subjects compared to patients with osteosarcoma and neuroectodermal bone tumors. A trend to a negative correlation between the concentrations of leptin and soluble Fas antigen in female patients with osteosarcoma and male patients with neuroectodermal bone tumors was revealed. The role of leptin and soluble Fas antigen in the pathogenesis of primary bone tumors is discussed.

Adolescent↗

[Ganglioneuroblastoma in Yemenite chameleon (Chamaeleo calyptratus): the first recorded case of a tumor of neuroectodermal histogenesis in reptiles].

Nerve tissue tumors are rarely encountered in reptiles and mainly represented by some documented cases of malignant peripheral nerve sheath tumor (MPNST). The paper is the first to describe a tumor mimicking MPNST by some ultrastructural features of tumor cells; however, significantly differing in the combination of immunohistochemical characteristics. Based on the data of electronic microscopy, immunohistochemistry, cytology, and histology, the tumor was classified as ganglioneuroblastoma. Since this nosological entity, unlike MPNST, cannot be assigned to a group of sarcomatoid tumors, the described pathology should be regarded as the first registered case of neuroectodermal histogenesis of tumors in reptiles.

Animals↗

Teratoma with malignant transformation: diverse malignant histologies arising in men with germ cell tumors.

PURPOSE: Teratoma with malignant transformation refers to a form of germ cell tumor in which a somatic teratomatous component becomes morphologically malignant and develops aggressive growth. We evaluated the spectrum of histologies, chromosomal abnormalities and clinical outcome in patients with teratoma with malignant transformation. MATERIALS AND METHODS: We identified 46 patients with germ cell tumor meeting morphologic criteria for malignant transformation. Histology, disease extent and treatment were correlated with survival. Tumors in 12 patients were studied by conventional cytogenetics or molecular genetic techniques for the isochromosome 12p [i(12p)], a marker for germ cell tumor, as well as other chromosomal abnormalities. RESULTS: The site of first detection of malignant transformation occurred in the primary tumor of 21 cases (44%), at a metastatic site in 20 (43%) and in both sites in 5 (10%). Sarcoma was the most frequent histology, identified in 29 patients (63%) with rhabdomyosarcoma the most common subtype. Seventeen tumors (37%) contained a solid tumor histology other than sarcoma, with adenocarcinoma and primitive neuroectodermal tumor as the most common histologies. Four patients with mediastinal germ cell tumor containing sarcoma also had hematological malignancies, including a focus of nonHodgkin's lymphoma in the mediastinal primary tumor (1) and nonlymphocytic leukemia in spleen or bone marrow (3). Patients who had teratoma with malignant transformation components confined to the testis or retroperitoneum completely resected experienced a longer survival than those with distant metastases or incompletely resected tumors (p = 0.003). Chromosomal abnormalities associated with germ cell tumor (i[12p]) were identified in 11 of 12 tumors containing adenocarcinoma, primitive neuroectodermal tumor, sarcoma and leukemia. In addition to i (12p), chromosomal rearrangements characteristic of the transformed histology were detected in 4 tumors. CONCLUSIONS: A variety of nongerm cell histologies, including sarcoma, adenocarcinoma, primitive neuroectodermal tumor and leukemia, may occur in association with germ cell tumor. Chromosomal abnormalities in these tumors include i (12p), reflecting germ cell tumor clonality, as well as chromosomal abnormalities associated with the transformed histology. These tumors do not respond like germ cell tumor to cisplatin-containing chemotherapy regimens. Treatment should be tailored according to that used in standard management of the transformed histology, and surgical resection is the mainstay of therapy.

Adenocarcinoma↗