1/12. Increased expression of 25-hydroxyvitamin D-1alpha-hydroxylase in dysgerminomas: a novel form of humoral hypercalcemia of malignancy.Humoral hypercalcemia of malignancy (HHM) is a common paraneoplastic disorder usually associated with increased synthesis of parathyroid hormone-related peptide (PTHrP). Unlike non-cancer forms of hypercalcemia, HHM does not routinely involve increased circulating levels of the active form of vitamin d, 1,25-dihydroxyvitamin D3 (1,25(OH)2D3). Dysgerminomas are a notable exception to this rule, previous reports having described hypercalcemia with elevated serum 1,25(OH)2D3. To investigate the etiology of this form of HHM we have characterized expression and activity of the enzyme that catalyzes synthesis of 1,25(OH)2D3, 25-hydroxyvitamin D-1alpha-hydroxylase (1alpha-hydroxylase), in a collection of 12 dysgerminomas. RT-PCR analyses indicated that mRNA for 1alpha-hydroxylase was increased 222-fold in dysgerminomas compared to non-tumor ovarian tissue. Parallel enzyme assays in tissue homogenates showed that dysgerminomas produced fivefold higher levels of 1,25(OH)2D3 compared to normal ovarian tissue. Immunolocalization studies indicated that 1alpha-hydroxylase was expressed by both tumor cells and by macrophages within the inflammatory cell infiltrate associated with dysgerminomas. The immunological nature of the increased 1,25(OH)2D3 production observed in dysgerminomas was further emphasized by correlation between expression of 1alpha-hydroxylase and the endotoxin recognition factors CD14 and toll-like receptor 4 (TLR4). These data suggest that inflammatory mechanisms associated with dysgerminomas are the underlying cause of the increased expression and activity of 1alpha-hydroxylase associated with these tumors. We further postulate that this autocrine/paracrine action of 1alpha-hydroxylase may lead to increased circulating levels of 1,25(OH)2D3 and a form of HHM which is distinct from that seen with PTHrP-secreting tumors.- - - - - - - - - - ranking = 1keywords = nature (Clic here for more details about this article) |
2/12. Further evidence consistent with Yqh as an indicator of risk of gonadal blastoma in Y-bearing mosaic turner syndrome.An 8-year-old girl with some features of turner syndrome and karyotype 45X/46XY had developed a bilateral gonadoblastoma in her rudimentary ovaries. Her normal y chromosome showed the characteristic distal fluorescence, as seen in her father's. Another mosaic, this time 45X/46XidicY, and also with some Turner features had rudimentary ovaries, but no gonadoblastoma had developed at age 14. The nature of her idicY, which showed no fluorescent distal Yq and had one of the centromeres inactivated, was confirmed by in situ hybridisation with a Yp-specific probe. Using primers from a human Yp-specific sequence, we amplified dna extracted from paraffin-embedded ovarian tissue from both cases, and from a normal testicle and a normal ovary as controls. The finding of the expected Y-derived PCR product in the rudimentary gonads from these mosaic patients indicates the presence of their y chromosome in both. We discuss the validity of the findings, and the possible role of sequences in or near the fluorescent part of Yq in the origin of gonadoblastoma in Y-bearing mosaic turner syndrome.- - - - - - - - - - ranking = 1keywords = nature (Clic here for more details about this article) |
3/12. fragile x syndrome and neoplasia.Among 100 males with fragile X [fra(X)] or Martin-Bell syndrome, two have developed malignancies. The first case, a 57-year-old man with fra(X) expression in 12% of peripheral blood lymphocytes, developed a seminoma of the left testis at age 45 years and in the right testis at age 50 years. The second case, a 16-year-old white boy with fra(X) expression in 23% of lymphocytes, developed a mucin-producing adenocarcinoma of the colon at age 14 years. Because of the unusual nature of the tumors observed in these patients and in 2 other patients from the literature, we suggest that individuals with the fra(X) syndrome may be at increased risk of cancer.- - - - - - - - - - ranking = 1keywords = nature (Clic here for more details about this article) |
4/12. Rare solitary metastasis to subcutaneous tissue from choriocarcinoma of testis.A rare case of solitary metastasis to subcutaneous tissue from choriocarcinoma of the testis which was predominantly seminoma is reported. The propensity for vascular route of metastasis of this tumor type producing the patient's clinical picture is presented. The human beta chorionic gonadotropin tumor marker elevation to 4,200 units preoperatively fell to normal two weeks postoperatively, suggesting a solitary metastatic site with total tumor extirpation. Nevertheless, it seemed prudent to give chemotherapy because the nature of the metastatic route suggested other microscopic sites of metastasis. The prognosis of this highly malignant neoplasm, while poorest of the array of testis tumors, has improved dramatically with the advent of effective chemotherapy.- - - - - - - - - - ranking = 1keywords = nature (Clic here for more details about this article) |
5/12. Combined occurrence of third ventricular germinoma and hypothalamic mixed glioma.A unique combination of occurrence of the 3rd ventricular germinoma and hypothalamic cystic mixed astrocytoma and oligodendroglioma is encountered in a 15-year-old man who presented clinically with stunted growth of the body, diabetes insipidus, and stupor. The germinoma was diagnosed by biopsy but the hypothalamic glioma was discovered at autopsy. Immunohistochemical localization of glial fibrillary acidic protein (GFAP) in the neoplastic cells confirmed the gliomatous nature of the hypothalamic lesion. The probability of multiple tumors should be kept in mind in dealing with intracranial neoplasms in order that the patient will be properly diagnosed and managed.- - - - - - - - - - ranking = 1keywords = nature (Clic here for more details about this article) |
6/12. Primitive neuroectodermal tumor of the testis. Report of a case.A 30-year-old man died of a testicular tumor with widespread metastases. Both the right testis and the adjoining epididymis were replaced by a mass that consisted mainly of small cells, but differentiated focally into medullary tubules, ependymal rosettes, and glia in which glial fibrillary acidic protein was demonstrated; rare foci of cartilage and cellular mesenchyme established the teratomatous nature of the neoplasm. We believe this is the first reported case of a primitive neuroectodermal tumor of the testis.- - - - - - - - - - ranking = 1keywords = nature (Clic here for more details about this article) |
7/12. Occlusive arteriopathy and brain tumor.Four cases with the association of occlusive arteriopathy and brain tumor are presented. A clinical analysis of these cases and cases reported in the literature revealed that occlusive arteriopathy at the base of the brain was often associated with a slowly growing basal tumor in children. Possible causes of occlusive arteriopathy in these cases were compression of the circle of willis by a slowly growing basal tumor, secondary artial occlusive changes by radiation therapy for a basal tumor, or vasculopathy associated with neurocutaneous syndrome. Symptoms of sudden onset or episodic nature suggest the presence of occlusive arteriopathy rather than the mass effect of a tumor. cerebral angiography is mandatory whenever computerized tomography (CT), performed to rule out recurrence of a basal tumor, shows an ischemic lesion with low-density areas without any evidence of mass effect of the tumor. cerebral angiography is also necessary when a basal tumor is suspected in children, particularly in cases associated with neurocutaneous syndrome and a basal tumor. Care should be taken not to scarify the abnormal vascular network at the base of the brain at the time of operation, because it is considered to be functioning as collateral circulation. The potential hazards of radiotherapy to radiation-induced occlusive changes of the circle of willis must be considered in treating a benign basal brain tumor in children. Even in adults, repeated large doses of irradiation could cause occlusive arteriopathy.- - - - - - - - - - ranking = 1keywords = nature (Clic here for more details about this article) |
8/12. seminoma of testicle metastatic to thyroid.A twenty-four-year-old white man is described who presented with seminoma and initially was treated with standard inguinal orchiectomy and radiation therapy for retroperitoneal disease. The case is reported because of the unusual nature of his later recurrence of disease, which was in the right lobe of the thyroid gland. This is a rare site for isolated recurrence, and there is a paucity of reports of metastatic tumor of any type to the thyroid gland. The patient had a complete remission after combined chemotherapy with cyclophosphamide, vinblastine, bleomycin, and cisplatin.- - - - - - - - - - ranking = 1keywords = nature (Clic here for more details about this article) |
9/12. Unilateral germinomas involving the basal ganglia and thalamus.Clinical characteristics of six cases of germinoma involving a unilateral basal ganglion and thalamus are summarized. The incidence was estimated as 10% of all intracranial germinomas. The average age at the onset was 10.5 years. The sex incidence showed a male dominance. The clinical course was slowly progressive, and the average duration between onset and diagnosis was 2 years 5 months. Common symptoms and signs were hemiparesis in all cases, fever of unknown origin and eye symptoms in most, mental deterioration and psychiatric signs in three, and convulsions, pubertas praecox, and diabetes insipidus in two. Signs of increased intracranial pressure were found in only two cases in the later state of the disease. early diagnosis is difficult because of nonspecific symptomatology and slow progression. Carotid angiography and pneumoencephalography showed abnormal findings compatible with basal ganglia and thalamic tumors, but not specific to germinoma. Ipsilateral cortical atrophy and ventricular dilatation might be significant findings. Radioisotope scanning was useful. Computerized tomography scans were the best method of detecting the location and nature of this tumor, and repeat scans showed response to radiation therapy.- - - - - - - - - - ranking = 1keywords = nature (Clic here for more details about this article) |
10/12. Cortical blindness and seizures possibly related to cisplatin, vinblastine, and bleomycin treatment of ovarian dysgerminoma.Ovarian dysgerminoma is the most common ovarian malignancy in young women. Conservative treatment is indicated in the reproductive-age woman who wishes to preserve childbearing capacity. This case report describes a patient with ovarian dysgerminoma who underwent chemotherapy with a cisplatin-vinblastine-bleomycin regimen that resulted in serious toxic complications--including cortical blindness and seizures--that were transient in nature. Although current chemotherapy regimens have dramatically improved the overall survival of women with germ-cell tumors, there are toxic complications such as those demonstrated in this report, and toxicity must be balanced against presumed benefit.- - - - - - - - - - ranking = 1keywords = nature (Clic here for more details about this article) |
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