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Query: UMLS:C0027651 (tumor)
 685,946 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The authors report on a case of radiation-induced malignant Triton tumor eg malignant schwannoma with rhabdomyoblastic differentiation). The tumor was situated in the brachial plexus of a patient who had received irradiation therapy 20 years previously for breast carcinoma. Pathological and immunohistological features have been described: coexpression of PS100, vimentin and desmin indicate a common neuroectodermic origin. A review of the literature has been presented in order to evaluate the diagnostic and prognostic characteristics of this unusual tumor and its relationship to neurofibromatosis.
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PMID:[Radiation-induced neurosarcoma. Clinical, histological and immunohistochemistry aspects]. 191 73

An HTLV-I tax transgenic mouse model develops a syndrome with similarities to type 1 neurofibromatosis (NF-1). To investigate possible associations between this human retrovirus and NF-1, we have analyzed 67 neurofibromas from Japan (where HTLV-I infection is endemic) and compared them with 21 cases from the United States. We were not able to identify virus in tumor tissue in either group. This suggests that HTLV-I infection is not commonly associated with NF-1.
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PMID:Absence of association of HTLV-I infection with type 1 neurofibromatosis in the United States or Japan. 192 22

This review considers the pathologic features of epithelial tumors and tumor-like lesions of the duodenum and highlights potential pitfalls in their histological diagnosis. The tumor-like lesions include Brunner's gland hamartoma, myoepithelial hamartoma, and the mucosal polyps of the Peutz-Jeghers and juvenile polyposis syndromes. The true neoplasms are of two broad groups. The first includes duodenal adenomas and carcinomas, whose microscopic features, histogenetic relationships, and clinical significance closely mimic their commoner counterparts in the large intestine and which, when multiple, are closely associated with familial adenomatous polyposis coli. The second includes a number of uncommon endocrine cell tumors showing a great diversity of histological pattern, and which may be single or multiple. Among these are typical argyrophil carcinoids, which may secrete gastrin to give rise to the Zollinger-Ellison syndrome, and which may occur as part of the inherited multiple endocrine neoplasia syndrome type 1 (MEN-1); glandular somatostatin-rich, apparently nonargyrophil, carcinoids containing psammoma bodies that can be easily confused histologically with adenocarcinomas, and which are linked to type 1 neurofibromatosis (von Recklinghausen's disease) and phaeochromocytoma; and the gangliocytic paraganglioma, a rare tumor composed of neural elements, ganglion cells, and endocrine cells. Accurate histologic diagnosis of mucosal tumors and tumor-like lesions of the duodenum is important not only for immediate patient management, but also because it may provide the first clue to the existence of an inherited tumor syndrome, with its broader implications for the patient's family and potentially important consequences for genetic counseling.
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PMID:Epithelial and neuroendocrine tumors of the duodenum. 192 22

Von Recklinghausen neurofibromatosis occurs in 1 in 3,000 live births; however, urologic manifestations are rare. There have been over 40 reported cases of neurofibroma of the bladder. Malignant degeneration of subcutaneous neurofibroma occurs in about 5 to 10 percent of patients. We believe we present the second reported case of a malignant peripheral nerve sheath tumor involving the bladder in a patient with this disorder.
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PMID:Malignant peripheral nerve sheath tumor (malignant schwannoma) of urinary bladder in von Recklinghausen neurofibromatosis. 194 63

A patient appeared to have von Recklinghausen type I neurofibromatosis, but her numerous cutaneous tumors were intradermal nevi and not neurofibromas. The patient had hundreds of 1- to 3-cm firm, flesh-colored, dome-shaped papules and pedunculated nodules on her buccal mucosa, eyelids, face, extremities, and trunk as well as a large, confluent, cerebriform tumor extending from the 12th thoracic vertebra to the sacrum. No cafe au lait macules, freckles, or Lisch nodules were present. Several hundred lesions were removed using the carbon dioxide laser. Histopathologic examination of all of the lesions revealed all of them to be intradermal nevi. Our patient's skin disease was clinically very similar to neurofibromatosis. We suggest our patient represents a distinct clinical entity that is related to environmental factors or a mutation that affected nevoblasts or melanoblasts and their derivatives during early embryo development.
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PMID:Abnormal nevoblast migration mimicking neurofibromatosis. 195 80

This report presents a very rare case of a malignant "Triton" tumor developing in the thyroid. Although malignant "Triton" tumors have often been known to develop in cases of neurofibromatosis, Von Recklinghausen's disease, this patient showed no clinical evidence of that disease. Total thyroidectomy including left standard radical neck dissection was followed by postoperative irradiation to the neck. Despite this, local and distant metastases developed four months after treatment and the recurrent foci did not respond to chemotherapy or irradiation. The clinical course of this case mimicked that of anaplastic carcinoma of the thyroid and interestingly, a minimal lesion of papillary adenocarcinoma was found to exist concurrently in the thyroid gland of this patient.
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PMID:Malignant "triton" tumor in the thyroid--a case report. 196 Sep 8

The phrase multiple endocrine neoplasia (MEN) generally denotes an association of tumors so specific as to constitute a syndrome. Three well-recognized such syndromes exist. All are autosomal dominant traits and all have been tentatively mapped to specific chromosomes. Other purported endocrine tumor syndromes have been suggested either as new entities or as subtypes of the existing MEN syndromes. The evidence in favor of these contentions is examined critically. Only one "new" association, that of pheochromocytomas and islet cell tumors, seems reasonable, and even in this setting, some relatives have had manifestations of von Hippel-Lindau syndrome. There is no compelling reason why such conditions as von Hippel-Lindau syndrome, peripheral neurofibromatosis, McCune-Albright syndrome, and others should be reclassified as MEN syndromes, although awareness of their collective endocrine abnormalities is clinically important.
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PMID:Multiple endocrine neoplasia: how many syndromes? 135 41

Facial nerve neuromas are uncommon tumors often confused with other tumors of the temporal bone and cerebellopontine angle. Radiologically, it may be impossible to differentiate an intracanalicular facial nerve neuroma from an acoustic neuroma. We present three case reports of facial nerve neuromas arising within the internal auditory canal to show the important magnetic resonance imaging features of these tumors. One tumor extended into the cerebellopontine angle, middle cranial fossa, and middle ear. Another filled the internal auditory canal and extended through the cerebellopontine angle to the brain stem. The third occurred in a patient who had neurofibromatosis as well as numerous other intracranial tumors. We feel that gadolinium-enhanced magnetic resonance imaging provides the most useful information in the preoperative assessment of this disorder.
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PMID:Magnetic resonance imaging of facial nerve neuromas. 198 48

Cytogenetic analysis of meningioma cells from one particular patient (MN32) displayed the stem-line karyo-type 45, XY, -1, 4p+, 22q-, 22q+, which thus had rearrangements of both chromosomes 22. The 22q+ marker appeared as a dicentric: 22 pter----q11::1p11----qter. The reciprocal product of this translocation has presumably been lost because it lacked a centromere. The 22q- chromosome also appeared to have lost sequences distal to band q11. We assumed that this marker could have been the result of a reciprocal translocation between chromosomes 4 and 22. To investigate the 4p+ and 22q- chromosomes in more detail, human-hamster somatic cell hybrids were constructed that segregated the 22q- and 4p+ chromosomes. Southern blot analysis with DNA from these hybrids showed that sequences from 22q were indeed translocated to 4p+ and that reciprocally sequences from 4p were translocated to 22q-, demonstrating a balanced t(4;22)(p16;q11). On the basis of these results we presume that in this tumor a tumor-suppressor gene is deleted in the case of the 22q+ marker and that the t(4;22) disrupts the second allele of this gene. The latter translocation was mapped between D22S1 and D22S15, a distance of 1 cM on the linkage map of this chromosome. The area in which we have located the translocation is within the region where the gene predisposing to neurofibromatosis 2 has been mapped.
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PMID:A t(4;22) in a meningioma points to the localization of a putative tumor-suppressor gene. 201 1

Loss of heterozygosity (LOH) at specific loci may help localize tumor suppressor genes involved in the formation of various familial and sporadic tumors. In addition, the genetic loci for a number of familial tumor syndromes have been mapped by linkage analysis. To explore the possible role of tumor suppressor genes in endocrine tumors, we tested 41 pheochromocytomas (34 sporadic and 7 familial) and 11 medullary thyroid cancers (MTC) (10 sporadic and 1 familial) for LOH near a variety of potentially important genetic loci: (a) the multiple endocrine neoplasia type 2A (MEN 2A) locus on chromosome 10; (b) the von Hippel-Lindau locus on 3p; and (c) the p53 and neurofibromatosis 1 loci on 17. We also examined chromosomes 1p and 22q because previous studies in a small number of pheochromocytomas and MTCs suggested LOH in these regions. Background rates for LOH were assessed using several "random" probes. Finally, we examined a number of clinical and histologic characteristics of these tumors for possible correlations with specific genetic alterations. LOH in the region of the MEN 2A locus was uncommon (0% for MTCs, 5% for pheochromocytomas). However, we found significant allelic losses in pheochromocytomas on chromosomes 1p (42%), 3p (16%), 17p (24%), and 22q (31%). We also noted a correlation between LOH on 1p and urinary excretion of metanephrine by these patients (P = 0.02). LOH on 1p, 3p, and 17p also appeared to be associated with increased tumor volume. Analysis of the smaller number of MTCs demonstrated allelic losses on chromosomes 1p and 22q. Our results suggest that tumor formation and/or progression in pheochromocytomas and MTCs involves multiple genes, analogous with the model proposed for colon carcinoma.
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PMID:Loss of heterozygosity suggests multiple genetic alterations in pheochromocytomas and medullary thyroid carcinomas. 202 40


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