Chromogranin A, a member of neuroendocrine secretory proteins as a selective marker for laboratory diagnosis of pheochromocytoma

The function of chromogranin A (CGA) is reviewed, and the radioimmunometric determination of plasma CGA was evaluated as a marker of pheochromocytoma using a comparison of pheochromocytoma patients immediately before surgery (group P, n=25, 635+/-451 ng/ml) with other groups of patients, i.e. pheochromocytoma patients approximately 1 year after removal of tumor (group PP, n=13, 69+/-33 ng/ml), medullary thyroid carcinoma patients (group M, n= 22, 106+/-59 ng/ml), congenital adrenal hyperplasy patients (n=33, 65+/-40 ng/ml), and controls (n=31, 66+/-29 ng/ml). A CGA level above cut off value 130 ng/ml was found in 24 of 25 patients in group P, 1 (relapse) of 13 patients in group PP, and 4 of 22 patients in group M. In the group P we found a significant association between the size of the tumors removed and plasma CGA concentrations (p=0.0016), and also a significant (p=0.0016) relationship between plasma CGA concentrations and PASS score rating the malignity of pheochromocytoma. We can conclude that plasma CGA concentration as determined by radioimmunometric assay (which is simple without the necessity of special laboratory equipment) is an effective marker of pheochromocytoma with association to malignity and tumor mass.

Robot-assisted pulmonary lobectomy

The authors present their first experience and the results of robot-assisted pulmonary lobectomies. The paper reports on the placement of the working channels, auxiliary minithoracotomies, the patient's position, the positions of the four-arm body of the da Vinci robotic system, and particularly the technique of lobectomy. In our institution, 4 robot-assisted lobectomies were performed in two women and two men (aged 45, 52, and 57, 67 years, respectively). The vessels were ligated mechanically with the use of the robot. An auxiliary minithoracotomy of a length of 5 cm was performed in the fifth intercostal area posterolaterally. The lower lobectomy was performed three times left and once right. The surgery was always supplemented with mediastinal lymphadenectomy. No serious complications were observed during the surgery or in the postoperative period. Robot-assisted lobectomy is a safe method of pulmonary resection in the early stages of bronchogenic carcinoma (Ia, Ib); it ensures a faster convalescence of the patient compared with open surgery (Ref. 14).

[Multiple lung metastasectomy for the poor differentiated metastatic synovial sarcoma]

OBJECTIVES

Synovial sarcoma is the rare indication for the pulmonary metastasectomy due to its aggressive biologic behavior and early dissemination. The radical surgical approach in therapy of the multiple pulmonary metastases could improve quality of life and median survival in carefully selected patients.

METHODS

From the group of 7 patients with the lung metastases of the synovial sarcoma operated in our department during the last 5 years we are presenting the case of the 39 years old man with the previous history of the surgical removal of the synovial sarcoma near the cubital fossa one year before. Considering the lungs as the only organ involved, bilateral complete metastasectomy through muscle sparing vertical thoracotomies was done. There were 12 metastases from all lung lobes with the exception of the right middle lobe. Analysis of the pathologist showed biphasic metastatic synovial sarcoma with the high mitotic activity. The 6 cycles of the MAID regime succeeded.

RESULTS

Median survival of the whole group is 25 months, there are 3 patients alive. In the above mentioned patient 1 year after the metastasectomy PET-CT showed focus of the 4th left rib suspected to be malignant. Wide resection of the rib was done, but no malignancy was disclosed, there were only reparative changes. The patient has been tolerated the oncological treatment very well and 45 months after the lung metastasectomy there are no sings of a malignant disease.

CONCLUSION

Lung metastasectomy of the multiple lung metastases of the synovial sarcoma is of value despite of uncertain long-term prognosis. It is recommended to consider the metastasectomy even in low differentiated tumors. The prerequisite for the effective treatment is a complete resection.

[Radioisotope department in Motol--the flow of time]

The radioisotope department in Motol was established on the 1st of June 1957 as the part of The Research Institute of Endocrinology founded by Assoc. Prof. Karel Silink. In the beginning, the department included 20 beds and its main activity consisted of radioiodine treatment of hyperthyroidism. Since 1965 the attention has been paid to the treatment of thyroid cancer, and this tradition continues till this time. The article reviews the main directions of development of this department since the very beginning to present.

[Thyroid carcinomas and Hirschsprung's disease--10-year experience with molecular genetic testing of the RET proto-oncogene]

In the last ten years, research has confirmed the role of the RET proto-oncogene in the pathogenesis of thyroid cancer such as medullary thyroid carcinoma (MTC) and papillary thyroid carcinoma (PTC), multiple endocrine neoplasia type 2 (MEN 2) and Hirschsprung's disease that can be associated with MTC or MEN 2. Through the use of molecular genetic testing, we are able to detect gene mutations and the course the disease might take can be predicted, thus enabling us to cure mutation carriers among the high-risk patients can at a very early, clinically asymptomatic stage of the disease; prophylactic total thyreoidectomy in said patients is recommended. At this juncture, there is extensive on-going research on the physiological role played by the RET proto-oncogene on the normal proliferation, differentiation and survival of the cell. Thanks to the new findings there are now possibilities of the theurapeutic use of gene therapy on an RET signaling cascade level in near future.

[Radionuclide screening in endocrinology]

The study provides an overview of current possibilities for use of nuclear medicine methods in endocrine diagnostics and therapy. Somatostatin receptor analogue is applied to the hypothalamus-hypophysis system, analogue medium to is used, in thyroid diagnostics, besides the determined tumour markers, tenchecium-labelled MIBI radioiodine 131 is used to determine and monitor carcinomas. Recently, rhTSH before starting thyroid carcinoma treatment is used. Neuroendocrinology tumours are suspected through 123I-MIBG; when scintigraphy is positive, therapeutic 131I-MIBG can be administrated. In diagnostics of the pituitary gland, two-step scintigraphy of MIBI is preferably used rather than subtraction methods. In patients with late or not significantly differenciated malignant tumours, positrone emission tomography is of benefit.

Double germline mutations in the RET Proto-oncogene in MEN 2A and MEN 2B kindreds

Medullary thyroid carcinoma (MTC) is a rare form of thyroid cancer representing about 10% of all thyroid malignancies. It occurs mostly as a sporadic tumor or in association with autosomal dominant inherited cancer syndromes--multiple endocrine neoplasia (MEN) types 2A and 2B and familial MTC. Germline mutations in exons 8, 10, 11, 13, 14, 15 and 16 of the RET proto-oncogene are found in most of the familial cases. There are only a few published data reporting multiple germline mutations in the RET proto-oncogene. We have detected double germline mutations in 2 different exons on the same RET allele in two MEN 2 families. In the MEN 2A family, double germline mutation in exons 10 (Cys620Phe) and 13 (Tyr791Phe) was detected. In the MEN 2B family, beside the classical germline mutation in exon 16 (Met918Thr) a second germline mutation in exon 13 (Tyr791Phe) was found. This study revealed that MEN 2 syndromes can also be caused by double germline mutations in the RET proto-oncogene and these families can be added to small worldwide cohort of families with multiple germline mutations.

New multiple somatic mutations in the RET proto-oncogene associated with a sporadic medullary thyroid carcinoma

Medullary thyroid carcinoma (MTC) occurs mostly as a sporadic tumor or in connection with inherited cancer syndromes-multiple endocrine neoplasia (MEN) types 2A and 2B and familial MTC. Germline mutations in the RET proto-oncogene are found in most of the familial cases. Somatic mutations in the RET proto-oncogene are detected in 23%-69% of patients with sporadic MTC. The most frequent somatic mutation is Met918Thr in exon 16 and only a small percentage of mutations in other RET exons have been observed. In a very few cases double mutations were found. Genetic screening for somatic mutations in RET exons 10, 11, 13, 14, 15, and 16 in Czech patients with sporadic MTC was carried out by DNA sequencing. This study presents a new triplesomatic mutation Gly911Asp, Met918Thr, and Glu921Lys in exon 16 of the RET proto-oncogene detected in an 18-year-old Czech male patient. In the second case, a new double-somatic mutation Val591Ile in exon 10 with a concomitant somatic mutation Met918Thr in exon 16 was found in a 77-year-old Czech female patient. These both newly described somatic multiple mutations were revealed in a hemizygous status, the loss of heterozygosity in tumor tissues in comparison with germline DNA was confirmed.

[The volumes of the thyroid gland in adults aged 18-65 years in the Czech Republic--determination of the norms]

OBJECTIVE

In the areas with moderate iodine deficit the sonographic examination of thyroid gland is a precious method of precise determination of its volume. The objective of the work was the sonographic examination of males and females aged 18-65 years and to determine the norms of the volumes of thyroid gland.

METHODS AND RESULTS

In total, by random sampling, there were sonographically examined 3 416 adults in 11 areas of the Czech Republic; there was chosen a set of 971 females and 681 males whose iodinuria level in first morning urine sample was equal or higher than 100 microg/l. This set was divided according to sex and into the age categories in 5-year interval. The measurement of 3 dimensions of the thyroid gland was determined by Medison-Kretz SA 600 sonographic device with the use of 7.5 MHz linear probe for the depth and width measurement and 3.5 MHz probe was used for the lengths measurement. The volume was determined for each lobe individually using Brunn's formula: V (ml) = 0.479 x length x depth x width. Our results imply the age-related increase of the volume of thyroid gland at both sexes (F-ratio = 1.99, p < 0.0001). At men and women the volume of thyroid gland fluently increases to the 30th year equally, from 30 years to 55 years it increases more rapidly in men while in women there is observed a moderate plateau. Further increase of the volume of thyroid gland is equally fluent from the age of 55 years.

CONCLUSION

We managed to determine first own norms of the volumes of thyroid gland for men and women aged 18-65 years in the Czech Republic in five-year age categories. In terms of practical use we recommend 90th percentile as a limit for the evaluation of upper limit of thyroid gland and the 10th percentile for the evaluation of lower limit of the volume of thyroid gland.

Exon 5 of the RET proto-oncogene: a newly detected risk exon for familial medullary thyroid carcinoma, a novel germ-line mutation Gly321Arg

Familial medullary thyroid carcinoma (FMTC) is an autosomal dominant inherited disease, characterized by germ-line mutations in the RET proto-oncogene, mainly in exons 10 and 11, but also in exons 13, 14 and 15. Recently, mutations in exons 8 and 16 associated with FMTC were also described. In the herein presented study, single strand conformation polymorphism (SSCP) method for rapid screening of mutations in the RET proto-oncogene and fluorescent sequencing method were used. In one Czech family with FMTC, we have identified a novel missense point mutation of the RET proto-oncogene in exon 5, that results in substitution of arginine by glycine at codon 321 in the cadherin-like domain of ret protein. It seems that this mutation causes FMTC as no other mutation was found in the classical risk exons (10, 11, 13, 14, 15 and 16) of the RET proto-oncogene. The mutation cosegregates with medullary thyroid carcinoma (MTC) or C cell hyperplasia (CCH) in two patients; two other family members are mutation carriers without clinical signs of MTC so far. To improve the diagnosis of FMTC, analysis of exon 5 of the RET proto-oncogene should be considered in families with no identified classical RET mutations.

Block copolymer adsorption from a homopolymer melt to an amine-terminated surface

Using neutron reflectometry, the adsorption of diblock copolymers from a neutral polystyrene (PS) matrix is studied as a function of substrate type and non-adsorbing block degree of polymerization. The block copolymer is poly(deutero styrene)-block-poly(methyl methacrylate) and the substrates are silicon oxide, SiO(x), and SiO(x) functionalized with (3-aminopropyl)triethoxysilane (APTES). We have determined the equilibrium volume fraction-depth profiles for such films, and compared them with volume fraction profiles generated by self-consistent mean-field (SCMF) theory and find good agreement between the experimental and theoretical data. SCMF calculations show that the segmental interaction energy between PS matrix chains and APTES is two orders of magnitude stronger than that between PS and SiO(x).

Screening of six risk exons of the RET proto-oncogene in families with medullary thyroid carcinoma in the Czech Republic

Medullary thyroid carcinoma (MTC) occurs as a sporadic form (75%) or as an autosomal dominant inherited familial disorder (25%) called familial MTC (FMTC) or as multiple endocrine neoplasia type 2 (MEN2) syndromes. Germ-line mutations in the rearranged during transfection (RET) proto-oncogene in exons 10, 11, 13, 14, 15 and 16 are known to be a cause of most of the familial forms. In this paper we report molecular genetic testing of 106 families with MTC (358 tested persons) from the Czech Republic in which we directly sequenced these six exons of the RET proto-oncogene. We detected germ-line mutations in 100% of MEN2B families (4/4 families), 90% of MEN2A families (9/10), 40% of FMTC families (4/10) and 7% of apparently sporadic MTC (6/82). Eleven different germ-line mutations were revealed. MEN2B was associated with mutation Met918 Thr in exon 16. In one MEN2B family beside this mutation the Tyr791 Phe was also found, which has not yet been reported. MEN2A was restricted to different mutations in exon 11 (codon 634). In FMTC and 'sporadic' MTC families the mutations in exons 10, 11, 13 and 14 were detected. The genotype/phenotype correlations are given. Genetic testing revealed germ-line mutations in 23 index patients, 24 family members and excluded them in 53 relatives.

Detection of the sentinel node in breast carcinoma using method of a single subcutaneous injection of radiopharmaceutical

The objective of this work is retrospective evaluation of results of the intraoperative detection of sentinel node in breast carcinoma after a single subcutaneous injection of radiopharmaceutical (RF) within a two-day protocol. From May/2001 to June/2002, lymphoscintigraphy of the sentinel node (SN) and its subsequent radioguided intraoperative detection (RGS) was performed in 43 women having stage T1-T2, N0 breast carcinoma. The static scans in the anterior and relevant lateral projections were performed using a gamma camera at approximately 30-minute intervals after the subcutaneous administration of 15 MBq 99mTc Senti-Scint, until the SN was displayed. The localization of the SN was marked on the overlying skin with a water-resistant permanent marker in 1-2 projections. RGS was accessed within 18-24 hours after the injection of the RF and all patients underwent an axillary dissection. The SN was detected in all patients, and in all cases was localized in the ipsilateral axilla. In 26 patients (60%), no metastatic process was found either in the SN or in any other axillary node. However, in one node, deposits of the carcinoma were detected in surrounding fatty tissue with propagation along the vessels and nerve. In 16 patients (37%), metastases in the SN were proved, in 7 cases (16%), a metastatic process was proved at the same time even in further lymph nodes. A number of false negative findings (5.8%) is consistent with the literature data. The method fails in the detection of intramammary localized SNs.

[Genetic causes of the thyroid carcinomas]

Thyroid carcinomas represent only 1% of all human malignancies, but more than 90% of endocrine tumors. It can be histologically divided into papillary, follicular, anaplastic or medullary thyroid carcinomas. Here we report the genetic causes of the development of these tumors. For papillary thyroid carcinoma formation of fused genes of tyrosine kinases (RET proto-oncogene, NTRK1 proto-oncogene and met proto-oncogene) with other genes is typical. They can activate these kinases and induce mutation in BRAF gene. The presence of PAX8/PPARgamma fused gene and ras mutations are important in the development of follicular thyroid carcinoma. Anaplastic thyroid carcinoma derives from the dedifferentiation of papillary and follicular carcinomas as a consequence of mutation or loss of heterozygozity in p53 gene. Medullary thyroid carcinoma comes from parafollicular C-cells, where point somatic and germ-line mutations (in familial form of medullary thyroid carcinoma or in multiple endocrine neoplasia type 2) in the RET proto-oncogene determine its development. Identification of these specific genetic alternations for each type of carcinoma can contribute to precision of the diagnosis, explanation of the origin of carcinomas, establishment of prognosis of the disease or in future as a tool for the target gene therapy.

The newly detected mutations in the RET proto-oncogene in exon 16 as a cause of sporadic medullary thyroid carcinoma

Medullary thyroid carcinoma (MTC) occurs as a sporadic form or, less frequently, as an autosomal dominant inherited familial disorder. Germline mutations in the RET proto-oncogene in exons 10, 11, 13, 14, 15, and 16 are found in most of the familial cases (nearly 95%). Somatic mutations in sporadic MTC are detected in 23-69% of patients. The most frequent somatic mutation is located in exon 16 at codon 918, and only a small percentage of mutations are found in exons 10, 11, 13, and 15. We have searched for somatic mutations in Czech MTC patients using direct sequencing. We report here two new somatic missense mutations in exon 16 of the RET proto-oncogene associated with the sporadic MTC detected in two Czech men. A homozygous mutation at codon 922 TCC(Ser)-->CCC(Pro) as a result of loss of heterozygosity was revealed in the first patient. In the second one a heterozygous mutation at codon 930 ACG(Thr)-->ATG(Met) was found.

[Pneumoperitoneum without perforation of the digestive tract]

The authors present an account on 9 patients who were detected in their department during the nine-year period from 1991-2000 with the finding of pneumoperitoneum where perforation of the digestive tract was not proved. In 4 of them (44%) conservative treatment was used, in the remaining 5 patients (56%) the condition called for surgical revision. The latter was made as an acute operation in four patients because of signs of peritoneal irritation, in one only after 4 days because of suspected tumours intestinal disease. As to the site of the assumed source of the non-perforation pneumoperitoneum we included 6 of them into the group abdominal area, (1x pneumatosis cystoides intestinalis, 1x aerogenic infection from a perforated abscess of the right liver lobe, 2x microtraumas of the wall of the cardio-esophageal transition with massive vomiting, 1x microtraumas of the lesser curvature of the stomach during extreme distension of the stomach after incorrect intubation and resuscitation, 1x passage of gas through the inflamed distended colonic wall in colitis), two patients into the thoracic area (1x in conjunction with pneumothorax, 1x with hydrothorax), 1 patient in the urogenital area (by the gynaecological route after repeated coitus and orogenital practices). The authors summarize on the basis of data in the literature and their own experience diagnostic and therapeutic possibilities of this relatively rare finding.

Heterotopy of thyroid tissue--a modified therapeutical approach

OBJECTIVES

The authors describe the classification of heterotopic thyroid tissue. A survey of more than 600 literature cases is provided. Different therapy approaches for these anomalies are discussed. Data from seven subsequent cases have been added to the existing literature data. The authors present an alternative approach to the therapy of heterotopic thyroid tissue.

MATERIALS AND METHODS

The records of seven patients treated for a heterotopy of the thyroid tissue as the Department of ENT and Head and Neck Surgery of First Medical school of the Charles University of Prague since 1.1.1991 to 1.1.2001 have been analyzed.

RESULTS

The first group: No surgery. This approach was used for children. In these patients the heterotopic thyroid tissue is the only thyroid tissue they have, but its function is not damaged and there are no mechanical symptoms (no airway obstruction and dysphagia). TSH substitution-suppression therapy is necessary for this group. Cooperation and follow up by the endocrinology, otolaryngology and pediatric departments is necessary. At a later age these patients can be treated as in the second group. The second group: Surgery. All patients in this group had heterotopic thyroid tissue. The total removal of thyroid tissue has been preferred. Carcinomatous change or the development of mechanical syndrome, dysphagia or airway obstruction is possible. Total removal is the best surgical approach. Various surgical methods are described in the literature (CO2 laser, intraoral, mandibulotomy, middle hyotomy etc.). These patients are treated as after total thyroidectomy and substitution therapy with synthetic thyroid hormones is necessary. The authors describe and add seven cases to the literature data. The authors describe radical removal of aberrant and accessory tissue [corrected].

Improved prediction of therapeutic absorbed doses of radioiodine in the treatment of thyroid carcinoma

We proposed an alternative to a monoexponential model of radioiodine kinetics to obtain a more accurate estimate of absorbed doses to postsurgical thyroid remnants. We suggested that part of the difference between the predicted and the actually absorbed therapeutic doses of (131)I, usually explained by radiation damage of thyroid cells, can be attributed to errors resulting from inadequate sampling of data and oversimplified modeling.

METHODS

A standard monoexponential model and alternative biphasic model (incorporating both radioiodine uptake and clearance) were used on 2 sets of patient data to fit time-activity measurements after administration of diagnostic and therapeutic activities of radioiodine. One set of data consisted of 633 records of routine measurements, and the second set consisted of 71 prospectively collected records with measurements performed more frequently and for a longer time. The time-activity curves derived from the 2 models were used to calculate residence times for diagnostic and therapeutic activities of (131)I, and the respective residence times were compared using the paired t test. Errors of fitting and prediction of therapeutic time-activity data were also calculated.

RESULTS

With both models, a statistically significant difference (P < 0.01) was found between residence times after diagnostic administration of (131)I and residence times after therapeutic administration of (131)I. However, the effects of biphasic modeling and of improved sampling substantially reduced the difference (P < 0.01). Errors of fitting and prediction were smaller with the biphasic model than with the monoexponential model (P < 0.01).

CONCLUSION

The biphasic model more accurately predicts (131)I kinetics when applied to measurements in the short interval after diagnostic administration of radioiodine. The minimum requirement for the biphasic model is measurement twice a day at intervals > 6 h for at least 3 d after administration.

[Surgical treatment of benign tumors of the thyroid gland]

Based on 22-year experience with surgery of 2107 benign thyroid tumours and data in the literature the authors evaluate some controversial problems from this sphere of thyrology pertaining to the definition and classification of benign tumours, their diagnosis, treatment and subsequent follow-up. Modern diagnostic procedures indicate that the actual number of true benign tumours is smaller than reported in some statistics and the assumption of monoclonal development of tumours is one of the most fundamental characteristics. The authors consider total lobectomy as minimal surgery, in case of uncertainty as regards possible malignancy further procedures depend on final histological examination. If the final finding alters the diagnosis from an originally benign tumour to a malignant one, the authors recommend a two-stage procedure to implement total thyroidectomy. In the authors' opinion total lobectomy is sufficient also in some variants of follicular adenoma--Hürtle's adenoma or atypical adenoma. Then however subsequent dispensarization is essential. After a partial operation (lobectomy) it is important to ensure substitution with thyroid hormones to suppress the function of TSH.

[Malignant lymphomas of the thyroid gland]

The authors evaluate their experience with malignant lymphomas of the thyroid gland, recorded in 22 patients from a total of 4501 operated on account of thyroid diseases in the course of 22 years. Although thyroid lymphomas are rare, their number is increasing. In localized findings curative procedures can be used, possibly supplemented by operations of the lymph nodes. The method of choice is still radiotherapy and surgery, in particular in lesions restricted to the thyroid gland. The role of chemotherapy is still controversial.