Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “MTC”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 199 records · Page 11Linked to original sources
PubMed2000

Medullary thyroid carcinoma in Northern Ireland, 1967-1997.

BACKGROUND: The experience of managing medullary thyroid carcinoma (MTC) in a specialist endocrine surgery unit was reviewed. METHODS: The case records of 38 patients (19 male, 19 female) treated over a 30 year period were studied. RESULTS: There were 23 (60.5%) patients with sporadic MTC while the remainder had familial MTC--12 multiple endocrine neoplasia (MEN) type 2A, two MEN type 2B, one non-MEN familial medullary thyroid carcinoma (FMTC). Sporadic MTC patients were significantly older at presentation (median 56 years, interquartile range 41.5-61.3 years) compared to MEN 2A patients (median 26 years interquartile range 17.5-34 years) and had more advanced stage of disease. Survival of MTC patients was significantly worse in sporadic disease than in those with MEN 2A (P < 0.0001). All familial cases had bilateral multifocal tumour whereas in sporadic patients only unilateral disease was seen. The availability of genetic testing now allows early identification of affected members of familial MTC kindreds. This has led to total thyroidectomy being performed on the basis of positive genetic screening alone in three patients (two MEN 2A, one FMTC), in all of whom widespread C-cell hyperplasia and microscopic multifocal invasive MTC were identified histologically. CONCLUSIONS: The management of MTC has changed during the study period with total thyroidectomy recommended as the primary procedure of choice for all patients. In the familial setting, positive genetic testing now allows thyroidectomy to be performed at an early pre-clinical stage, with the hope of permanent cure.

Adolescent↗
PubMed2001

[Germline mutations of the ret proto-oncogene in Chilean patients with hereditary and sporadic medullary thyroid carcinoma].

BACKGROUND: Medullary thyroid carcinoma (MTC) may occur either as a sporadic or familial disease. Multiple endocrine neoplasia (MEN) type 2, inherited as an autosomal dominant disease, is characterized by MTC only (FMTC) or coexistence of MTC with other endocrine neoplasia (NEM 2A, 2B). Germline mutations of the RET proto-oncogene (cRet) are found in the inherited forms and in some apparently sporadic MTC cases. AIM: To study RET mutations in 8 families with MEN 2. MATERIAL AND METHODS: RET mutations were screened in peripheral blood DNA from 18 patients and 87 high risk carriers belonging to 8 MEN 2 families and 52 sporadic MTC. Exons 10, 11, 13, 14, 15 and 16 of the c-Ret were amplified by polymerase chain reaction (PCR) and examined by direct sequencing of PCR products and/or restriction enzyme analysis. RESULTS: Five MEN 2A and one FMTC families with a germline mutation at codon 634, one MEN 2A and one FMTC family carrying a mutation at codon 620 were identified. Mutations were found in 23 out of 87 high risk carriers. In addition, we detected a S891A (exon 15) germline mutation in a sporadic MTC patient and in one out of her three sons and V804M (exon 14) in another sporadic MTC case and in one out of his six relatives, indicating in both cases the presence of a sporadic misclassified familial disease. CONCLUSIONS: These results underscore the importance of routine application of c-Ret testing in all cases of MTC either familial or sporadic.

Adolescent↗
PubMed2003

CEP-701 and CEP-751 inhibit constitutively activated RET tyrosine kinase activity and block medullary thyroid carcinoma cell growth.

All of the cases of medullary thyroid carcinoma (MTC) express the RET receptor tyrosine kinase. In essentially all of the hereditary cases and approximately 40% of the sporadic cases of MTC, the RET kinase is constitutively activated by mutation. This suggests that RET may be an effective therapeutic target for treatment of MTC. We show that the indolocarbazole derivatives, CEP-701 and CEP-751, inhibit RET in MTC cells. These compounds effectively inhibit RET phosphorylation in a dose-dependent manner at concentrations <100 nM in 0.5% serum and at somewhat higher concentrations in the presence of 16% serum. They also blocked the growth of these MTC cells in culture. CEP-751 and its prodrug, CEP-2563, also inhibited tumor growth in MTC cell xenografts. These results show that inhibiting RET can block the growth of MTC cells and may have a therapeutic benefit in MTC.

Animals↗
PubMed1992

PDN-21 (katacalcin) and chromogranin A: tumor markers for medullary thyroid carcinoma.

The malignant C-cell releases several markers of potential clinical significance into the circulation. To determine the usefulness of these markers for management of medullary thyroid carcinoma (MTC), it is necessary to compare the usefulness of these markers with calcitonin (CT), the classical tumor marker for MTC. Measurement of serum concentrations of the peptide PDN-21 (katacalcin), a carboxyterminal cleavage product of procalcitonin, showed a high correlation with serum CT levels (r = 0.99, P < 0.01, n = 65 patients with MTC). The presence of equimolar concentrations of CT and PDN-21 (CT/PDN-21 molar ratio = 0.95 +/- 0.33) indicates the peptide is cosecreted with CT. Stimulation of CT release by intravenous pentagastrin was associated with a parallel increase of PDN-21, providing further evidence of cosecretion of these two peptides. Finally, measurement of either PDN-21 or CT in selective venous catheterization specimens was useful for localization of MTC. Chromogranin A (CgA) levels were also measured in patients with MTC. Circulating levels were elevated in most patients with advanced disease. There was a moderate correlation between CgA and CT serum levels (r = 0.87, P < 0.01, n = 61 patients with MTC). Pentagastrin did not stimulate CgA, and the long half-life of CgA in the circulation did not make it possible to use this peptide for tumor localization by selective venous catheterization. We conclude that measurement of PDN-21 provides an independent assay system for diagnosis, localization, and postoperative management of MTC, whereas CgA measurement is not useful in early diagnosis of MTC and is of limited value for localization or management of progressive disease.

Biomarkers, Tumor↗
PubMed2006

Targeting, toxicity, and efficacy of 2-step, pretargeted radioimmunotherapy using a chimeric bispecific antibody and 131I-labeled bivalent hapten in a phase I optimization clinical trial.

UNLABELLED: Safety, targeting, and antitumor efficacy of pretargeted radioimmunotherapy using anti-carcinoembryonic antigen (CEA) hMN-14 x m734 bispecific antibody (BsmAb) and 131I-di-diethylenetriamine pentaacetic acid (DTPA)-indium hapten were evaluated in a phase I study performed on patients with CEA-expressing tumors. METHODS: Twenty-two patients with nonmedullary thyroid carcinoma (non-MTC) (group I, 13 patients) or medullary thyroid carcinoma (MTC) (group II, 9 patients) were enrolled. These patients received a 75 mg/m2 (11 patients) or 40 mg/m2 (11 patients) dose of BsmAb and escalating activities of (131)I-di-DTPA-indium 5 d later. Toxicity and tumor response were assessed in 20 patients who received a therapeutic (>2.2 GBq) hapten dose of radioactivity. RESULTS: The percentage of lesions detected by immunoscintigraphy after injection of the therapeutic dose of hapten was 70% on an anatomic-site basis. High bone uptake was relatively frequent. A transient grade I or II hepatic toxicity was observed in 5 patients (45%) injected with 75 mg/m2 of BsmAb and in 1 patient (11%) injected with 40 mg/m2. No other nonhematologic toxicity was observed. With 75 mg/m2 of BsmAb, hematologic toxicity was high: 5 cases of grade III or IV leukopenia (45%) and 5 cases of grade III or IV thrombopenia (45%). With a 40 mg/m2 dose of BsmAb, hematologic toxicity was reduced significantly: 3 cases of grade III or IV leukopenia (33%) and 1 case of grade III or IV thrombopenia (11%) (P = 0.02). Toxicity was significantly higher in MTC patients than in non-MTC patients (P = 0.019). Nine cases of tumor stabilization of 3 mo to more than 12 mo were observed (45%), 6 in the MTC group and 3 in the non-MTC group. The rate of disease stabilization was significantly higher with 75 mg/m2 of BsmAb (64%) than with 40 mg/m2 (22%) (P = 0.04). Human antimouse antibody elevation was observed in 1 patient (8%) and human antihuman antibody in 4 (33%). CONCLUSION: A BsmAb dose of 40 mg/m2 and a 5-d interval appeared to be a better dose/schedule regimen, with acceptable toxicity. Under these conditions, the maximal tolerated activity was 3 GBq of 131I-di-DTPA-indium in MTC patients. In non-MTC patients, dose escalation should continue.

Adult↗
PubMed1991

[Study of detailed conditions in DNA probe test by use of Gen-Probe Rapid Diagnostic System for identification of Mycobacterium avium complex and Mycobacterium tuberculosis complex].

In order to improve feasibility of technical procedures in Gen Probe Rapid Diagnostic System (Gen Probe Inc., San Diego, CA, U.S.A.) for identification of Mycobacterium avium complex (MAC) and M. tuberculosis complex (MTC), we studied several test conditions in the DNA probe testing, such as stability of test bacterial suspension, optimal duration of bacterial cultivation, the number of organisms in test bacterial suspension required for accurate determination, and so on. With respect to concentration of organisms (MAC and MTC) in test bacterial suspension (0.1ml), we found that 5-fold dilution as well as 5-fold condensation of the standard bacterial suspension (McFarland No.1) gave substantially the same result as in the case where bacterial suspension at the standard concentration was used. This indicates that the test bacterial suspensions (0.1ml) containing either 1.5 X 10(7)-5 X 10(8) of MAC or 3 X 10(5)-8 X 10(6) of MTC are available for the DNA probe testing. Test bacterial suspension at McFarland No.1 prepared from fresh cultures (3-4 week-old) could be stored either at -80, -20 or 4 degrees C at least for 17 weeks without significant loss of reactivity to M. avium, M. intracellulare and MTC DNA probes. In this case, stability of DNA probe-reactivity was preserved in the following order: MTC, M. avium and M. intracellulare. Concerning the age of bacterial cultures, at least 16-week-old cultures of MAC and MTC after initial appearance of cell growth on 1% Ogawa's egg media were sufficiently reactive to either MAC or MTC DNA probe. In this case, MTC showed most stable reactivity during the course of long-term cultivation.(ABSTRACT TRUNCATED AT 250 WORDS)

DNA Probes↗
PubMed1991

Transport kinetics of pseudouridine during hemodialysis and continuous ambulatory peritoneal dialysis.

It has been found that the concentrations of pseudouridine in serum of patients undergoing continuous ambulatory peritoneal dialysis (CAPD) are higher than those in patients undergoing hemodialysis. We analyzed whether this could be caused by a lower rate of transport in CAPD when compared with hemodialysis. Mass transfer area coefficients (MTCs) for urea, creatinine, uric acid, and pseudouridine were determined in nine patients undergoing hemodialysis as dialyzer clearances and in 14 patients undergoing CAPD during a 4-hour dwell with 2 L dialysate with glucose, 70 mmol/L. The theoretical MTC of pseudouridine (TPSI), calculated by extrapolation to its molecular weight by use of the MTC of urea, creatinine, and uric acid, was higher than the observed MTC of pseudouridine, both in hemodialysis (136 vs 112 ml/min, p less than 0.025) and in CAPD (6.9 vs 3.4 ml/min, p less than 0.001). The pseudouridine/TPSI MTC ratio was lower during CAPD than during hemodialysis (0.47 vs 0.83, p less than 0.0005), indicating a lower level of transport during CAPD. In vitro experiments with nuclear magnetic resonance spectroscopy supported the hypothesis of glucose-induced molecular association of pseudouridine. Therefore, dialysate containing 10 mmol/L glucose was compared with that containing 70 mmol/L glucose in eight patients undergoing CAPD. The MTC of pseudouridine was higher during the experiments with dialysate containing 10 mmol/L glucose (3.5 +/- 2.0 ml/min vs 2.7 +/- 1.9 ml/min, p less than 0.05). This was also found for the pseudouridine/TPSI MTC ratio (0.61 vs 0.41, p less than 0.02) and the pseudouridine/creatinine MTC ratio (0.33 vs 0.25, p less than 0.02), favoring glucose-induced decrease of MTC-pseudouridine.(ABSTRACT TRUNCATED AT 250 WORDS)

Biological Transport↗
PubMed1989

Diagnosis, management, and pathogenetic studies in medullary thyroid carcinoma syndrome.

A retrospective study of 224 patients with medullary thyroid carcinoma (MTC) diagnosed between 1963 and 1988 was performed to 1) establish the diagnosis of MTC in early childhood, 2) establish the role of prophylactic regional lymphadenectomy in patients with MTC, 3) study the effect of chemotherapy on MTC patients with metastatic disease, 4) study the effect of somatostatin analog 201-995 (Sandoz Pharmaceuticals) on the frequency of diarrhea in MTC, and 5) locate the common region(s) of gene deletion on chromosome 1 and examine the loss of heterozygosity on chromosome 10 in tumors. Our data indicated that a progressive rise of serum calcitonin in early childhood (rather than the expected fall with age seen in normal subjects) is diagnostic of MTC. No differences in clinical course of prognosis were observed between patients with MTC localized to the thyroid who had prophylactic neck node dissection and those who did not. Conventional chemotherapy had no significant benefit in the treatment of patients with metastatic disease. The somatostatin analog was found to be an effective drug in the treatment of diarrhea associated with MTC. Allelic losses were frequently found in MTCs and pheochromocytomas, and the loss of DNA sequences in these tumors appeared to involve the distal third of the short arm of chromosome 1, with a common breakpoint at 1p32.

Adrenal Gland Neoplasms↗
PubMed1994

Pancreas cancer-associated antigen (PCAA) in medullary thyroid carcinoma.

Pancreas cancer-associated antigen (PCAA), primarily isolated from the ascites of pancreatic cancer (PC) patients, is strongly positive in PC, colon cancer and normal colonic mucosa. In immunohistochemical staining of tumor tissues with antibodies, medullary thyroid carcinoma (MTC) was no less strongly positive for PCAA than PC, and we studied its details. Antibodies to PCAA, calcitonin and CEA were used in the immunostaining of normal thyroid tissues and thyroid tissues from patients with adenomas, MTC, papillary carcinomas, and follicular carcinomas. The PCAA from the liver metastases of MTC was studied for molecular weight and antigenicity in comparison with the PCAA from the ascites of PC patients. Serum levels of PCAA were determined in MTC patients. Of 11 patients with MTC, PCAA, calcitonin and CEA were studied immunohistologically and positive in 10, 11 and 10 patients, respectively. The PCAA from the metastases had a molecular weight of about 700,000, and was immunochemically identical to that from the ascites of PC patients. Serum levels of PCAA were elevated in 4 of 6 MTC patients. The thyroid tissues from the MTC patients, familial or non-familial, were as strongly positive for PCAA as for calcitonin and CEA. It was antigenically identical to that of PC origin, and positive in the serum of MTC patients.

Adenocarcinoma, Follicular↗
PubMed1994

Medullary thyroid carcinoma in multiple endocrine neoplasia types 2A and 2B.

BACKGROUND: Considerable emphasis has been placed on early diagnosis and surgery for multiple endocrine neoplasia (MEN)-related medullary thyroid carcinoma (MTC) during the past two decades. Genetic screening now promises earlier and more accurate diagnosis. We examine our experience with MTC in MEN 2A and MEN 2B and assess the benefits of biochemical screening during the past 20 years. PATIENTS AND METHODS: Seventy-seven patients undergoing 63 primary total thyroidectomies and 14 reoperative procedures for MEN-related invasive MTC and/or preinvasive C-cell hyperplasia are reported. Fifty-eight patients had MEN 2A and 19 had MEN 2B; 79% of patients had a family history of MTC; 27% had pheochromocytoma, and 25% had hyperparathyroidism. RESULTS: Patients with MEN 2B had more advanced disease than those with MEN 2A, in spite of presentation at a younger age (15 years versus 24 years). Every patient with MEN 2B had invasive carcinoma, whereas 14% of patients with MEN 2A had C-cell hyperplasia without invasive disease. Nodal metastases were found less frequently in MEN 2A (14%) than MEN 2B (38%), and biochemical cure was achieved in 56% of patients with MEN 2A compared with none in patients with MEN 2B. Among patients with MEN 2A the occurrence of invasive carcinoma increased with age (p = 0.0003); 40% of patients for less than 5 years had invasive MTC compared with 100% at more than 20 years. Cause-specific mortality among patients with MEN and invasive tumors at 6, 12, and 18 years was 2%, 4%, and 7%, respectively, lower than that of patients with sporadic MTC (12%, 17%, and 23%, respectively) treated during the same time period (p = 0.028). CONCLUSIONS: Intensive biochemical screening of MEN 2 kindreds for MTC can result in detection of early disease and a significant prospect of surgical cure. Genetic testing promises additional benefits through more reliable detection of preinvasive disease, allowing prophylactic thyroidectomy in infancy. In MEN 2B, MTC is considerably more aggressive than in MEN 2A. A policy of routine thyroidectomy in infants with MEN 2B, regardless of serum calcitonin levels, is justified.

Adolescent↗
PubMed1998

Bcl-2 and c-Myc, but not bax and p53, are expressed during human medullary thyroid tumorigenesis.

Medullary thyroid carcinoma (MTC) is a tumor of parafollicular cells of the thyroid gland. It has served as a useful experimental model for the study of tumor proliferation and differentiation. Although recent studies have identified the gene involved in familial forms of MTC, little is known about the molecular pathogenesis of the sporadic variants of this tumor. It has become increasingly clear that deregulation of programmed cell death is a critical component in multistep tumorigenesis. The present investigation was undertaken to determine whether similar molecular events occur in human MTC. Eighteen MTCs from 18 patients (including 12 sporadic and six familial cases and one metastatic lymph gland) and a MTC cell line (TT cells) were used in this study for detecting the expression of apoptosis-regulatory genes bcl-2, bax, c-myc, and p53. Immunohistochemical results showed that all MTC tumor samples displayed Bcl-2 and c-Myc immunoreactivity, whereas only 4 and 2 tumors showed a minority of cells positive for Bax and p53, respectively. Western and Northern blotting showed high levels of 26-kd Bcl-2 protein and bcl-2 transcript. The co-expression of Bcl-2 and c-Myc was also detected in the TT cells by indirect fluorescence immunohistochemistry and Western blotting. Moreover, Bcl-2 immunoreactivity was also found in C-cell hyperplasia from familial patients indicating that expression of this oncogene may represent an early event in the pathogenesis of MTC. The present study suggests that deregulation of programmed cell death may be a critical component in multistep tumorigenesis of MTC and that the frequent expression of the Bcl-2 oncoprotein in these tumors may contribute to their pathogenesis. The genetic complementation of simultaneously deregulated bcl-2 and c-myc may be implicated in the multistep tumorigenesis of human MTC.

Adolescent↗
PubMed1998

[Early therapeutic management of patients genetically predisposed to medullary thyroid cancer].

STUDY: The aim of our study was to study therapeutic results after thyroidectomy in patients positive for predictive genetic analysis and with preoperative calcitonin (CT) response to pentagastlin (Pg) < 150 pg/ml. MATERIAL AND METHODS: 36 patients (13 F, 23 M) were selected: 13 F-MTC from 8 families, 22 MEN 2A from 15 families and 1 MEN 2B. They were positive for direct RET mutation analysis. CT was assayed by immunoradiometric method before and after Pg. Pg test results before and after thyroidectomy, age at operation and histologic results were analysed. RESULTS: Mean preoperative peak CT was 82.5 +/- 34.0 pg/ml (22-133): among these 36 patients preoperative basal and peak CT were normal in 16 and 2 patients respectively. F-MTC and MEN 2A patients were different according to their preoperative peak CT levels (58.1 +/- 24.0 vs 97.6 +/- 31.3) pg/ml, p < 0.01) and age at thyroidectomy (20.4 +/- 10.5 vs 11.6 +/- 7.6 years, p < 0.01 by Mann-Whitney test). Total thyroidectomy was performed in all patients at a mean age of 14.8 +/- 9.8 years (2.5-41.7) and was associated with lymph node dissection in 30 cases. The 2 F-MTC patients with normal preoperative peak CT levels had bilateral C-cell hyperplasia (CCH) associated with uni or bilateral micro-MTC. Other patients had uni or bilateral micro MTC except 4 who had isolated CCH without carcinoma. The age of two MEN-2A and 1 MEN 2B patients with micro-MTC ranged from 2.5 to 4.7 yr. Micro MTC was present in 100% of MEN-2A cases after the age of 10 yr. There were no lymph nodes metastases. During postoperative survey, the last PG tests (n = 33) were performed 27.5 months (1-92) after thyroidectomy: peak CT values were always < 10 pg/ml. IN CONCLUSION: Thyroidectomy should be performed at a very young age in RET mutation carriers, regardless of the plasma CT values. This choice is justified in NEM-2A and NEM-2B patients but must be discussed in F-MTC families with less aggressive forms of the disease.

Adolescent↗
PubMed1979

C-cell disease of the thyroid gland in multiple endocrine neoplasia, type 2b.

Multiple endocrine neoplasia, type 2b (MEN 2b) is a disorder characterized by C-cell disease of the thyroid gland (medullary carcinoma or C-cell hyperplasia, or both), pheochromocytoma, ganglioneuromatosis, and skeletal and connective tissue abnormalities. The medullary thyroid carcinoma (MTC) is bilateral and multicentric; it metastasizes locally and distally, often before the disease is recognized. Histologically proven C-cell disease was present in 89 of the 107 patients (83%) reported with the condition, including 17 Mayo Clinic patients (average age at diagnosis, 19.2 years). Nineteen of the 107 patients (18%) died of MTC (average age at death, 25.3 years); 9 (8%) succumbed to pheochromocytoma, 7 of these also having metastatic MTC; 13 12%) died of other or unknown causes, but 2 of these had disseminated MTC as well; 29 (27%) survive with metastatic MTC; an additional 21 (20%) are alive, but concentrations of plasma immunoreactive calcitonin (iCT) have not been measured; 6 more (6%), 5 of whom had thyroidectomy before the age of 12 years, are alive with normal plasma concentrations of iCT; and the remaining 10 (9%) have been lost to follow-up. Survival of patients with MEN 2b after operation was reduced when compared with that of a control population -- 80% versus 99% at 5 years and 50% versus 98% at 10 years. The only effective treatment for MTC is total thyroidectomy before metastasis occurs. "Cure" of MTC in patients with MEN 2b has generally been obtained in those having total thyroidectomy before age 12. Therefore, in young patients suspected of having MEN 2b, we recommend prompt evaluation of C-cell function by measurement of stimulated concentrations of iCT and treatment by total thyroidectomy if results are abnormal.

Adolescent↗
PubMed1987

Radioiodinated meta-iodobenzylguanidine uptake in medullary thyroid cancer. A French cooperative study.

Fifty meta-iodobenzylguanidine (MIBG) scintiscans were performed in three groups of medullary thyroid cancer (MTC) patients. Group 1 (n = 11) included treated patients with normal calcitonin levels; Group 2 (n = 24) included patients with elevated calcitonin levels due to sporadic and isolated MTC; Group 3 (n = 15) included patients with elevated calcitonin levels due to familial MTC or multiple endocrine neoplasia Type IIA syndrome (MEN). In Group 1 three pheochromocytoma were depicted by MIBG scintiscan. In Group 2 MTC was seen in a small number of patients (3 of 24). In Group 3, besides adrenal hyperplasia and pheochromocytoma four patients, MIBG scintigraphy showed where MTC had localized and spread in almost half of patients (7 of 15). MIBG uptake occurred in patients with relatively high calcitonin level (greater than 0.6 nmol/l). These data indicate that in patients with familial MTC or MEN syndrome, MIBG scintiscan can be useful not only in detecting associated pheochromocytoma, but also in showing MTC.

3-Iodobenzylguanidine↗
PubMed2004

Phenotypic expression of a family with multiple endocrine neoplasia type 2A due to a RET mutation at codon 618.

BACKGROUND: Multiple endocrine neoplasia type 2A (MEN2A) is caused by missense mutations in the RET proto-oncogene on chromosome 10. This paper reports the phenotypic expression of a family with MEN2A, in which serine substitutes for cysteine at codon 618 in exon 10 of the RET gene. It was first claimed that medullary thyroid cancer (MTC) with this rare mutation led to mild disease; this has recently been updated to intermediate-high risk, based on stratified genetic information. METHODS: The family was mapped over six generations. In 1971 family members were invited to join a screening programme. Genetic testing was started in 1994. RESULTS: Twenty-two individuals with MTC were identified, 16 by the screening programme. One screened patient had a phaeochromocytoma and four had hyperparathyroidism. At surgery for MTC 12 patients had local tumour metastases and two young patients also had liver metastases. No screened patient died from MTC during a mean observation time of 19 years. Six other family members were diagnosed with MTC by signs and symptoms, five of whom died from MTC. CONCLUSION: Because of the great interindividual differences in tumour aggressiveness within the family it is impossible to predict whether an individual gene carrier will have an aggressive MTC or not. This unpredictability is an additional argument, besides those obtained in stratified genetic studies, for operating on gene carriers at young age.

Adolescent↗
PubMedDate not supplied

Use of magnetization transfer contrast to improve single breath-hold three-dimensional MR-portography with bolus injection of gadopentetate dimeglumine: a preliminary report.

We investigated whether better visualization of the intrahepatic portal system could be obtained by adding magnetization transfer contrast (MTC) to three-dimensional MR portography (3D-MRP). In 15 healthy volunteers, 3D fast low-angle shot images combined with an off-resonance pulse were obtained after bolus injection of gadopentetate dimeglumine during one period of breath-holding. Within 1 week after injection, MR images without MTC were obtained using the same scanning condition. MRPs with and without the MTC pulse were compared quantitatively and qualitatively. The contrast-to-noise ratio of the portal vein-liver was significantly higher in the group imaged with the addition of MTC. Qualitatively, the use of MTC improved peripheral portal branch depiction on maximum-intensity projection images. Even when the MTC pulse was added to the conventional method of 3D data collection, it was possible to obtain images within one period of breath-holding. In conclusion, the use of MTC can substantially enhance the quality of 3D-MRPs.

Adult↗
PubMedDate not supplied

Magnetization transfer contrast of hepatic lesions in breath-hold gradient-echo images of different T1 weighting.

Seventeen patients with hepatic lesions [six metastases from colon, breast, and gallbladder carcinoma; one gallbladder carcinoma; five hepatocellular carcinoma; three focal nodular hyperplasia (FNH); one adenoma; and one cyst] were examined by MR breath-hold two-dimensional gradient-echo imaging to assess the potential of magnetization transfer contrast (MTC) for improved conspicuity and classification. Imaging sequences were applied with and without irradiation of off-resonant radiofrequency (RF) prepulses, but other parameters were unchanged. Therefore, quantitative assessment of MTC could be performed. In contrast to former examinations of other researchers, no significant difference of MTC was found between malignant liver lesions and benign lesions as FNH or adenoma. MTC might provide differentiation between hemangioma and cysts versus solid tumors, but MTC is not capable of distinguishing benign and malignant types of solid liver tumors. Effects of unchanged MTC prepulses on signal intensity of normal liver tissue and most lesions were more pronounced for nearly proton density-weighted fast low-angle shot (FLASH) images than for T1-weighted FLASH images, obtained by using higher excitation flip angles. Liver-to-lesion contrast could not be improved clearly by MTC prepulses. The contrast between liver and lesions in the gradient-echo breath-hold images was compared with standard T1- and T2-weighted spin-echo images. Liver-to-lesion contrast in the breath-hold images was found to be inferior to T2-weighted spin-echo images in 14 of 17 cases. Lesion conspicuity in regions near the diaphragm was better in breath-hold images, because problems with marked breathing motion (as in standard imaging) could be avoided.

Adult↗
PubMed2005

Medullary thyroid carcinoma: including MEN 2A and MEN 2B syndromes.

Medullary thyroid carcinoma (MTC) is a rare malignancy with several distinctive features that distinguish its management from other thyroid cancers. First, MTC may be sporadic (75% of cases), or may occur as a manifestation of the hereditary syndrome Multiple Endocrine Neoplasia type 2 (MEN 2) (25% of cases). Additionally, while MTC is more difficult to cure than differentiated thyroid cancer and has higher rates of recurrence and mortality, it is usually a slow growing tumor compared with other malignancies. Finally, unlike differentiated thyroid cancer, there is no known effective systemic therapy for MTC. MTC cells do not concentrate radioactive iodine, and MTC does not respond well to external beam radiation or conventional cytotoxic chemotherapy. These distinguishing features should be considered in planning surgical management of MTC.

Antineoplastic Combined Chemotherapy Protocols↗