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C Dotzenrath

Publications and source records attributed to C Dotzenrath.

At least 37 records · Page 2Linked to original sources
PubMed1997

[Surgical therapy of neuroendocrine tumors of the thymus].

Neuroendocrine tumors of the thymus, also known as thymic carcinoids, are rare tumors of the anterior mediastinum. They occur sporadically or in association with MEN I syndrome. We present five patients (four male, one female; age of first manifestation 19-53 years) who were operated on at our hospital between 1984 and 1995 for neuroendocrine thymic tumors. A hormone-producing tumor presented with Cushing's syndrome in two patients. Two patients had MEN I syndrome. Only in the female patient the primary tumor was confined to the thymus. We found lymph node metastases in three patients and a distant metastasis in one. The neuroendocrine tumors have a high rate of local recurrences and thus we performed 11 operations using a transthoracic or transsternal approach. Since there was no operative mortality and adjuvant therapies are of limited value, we recommend surgery even in case of recurrence.

Adult↗
PubMed1997

[Results of selective venous site-specific catheterization in occult C-cell carcinoma of the thyroid gland].

BACKGROUND: Medullary thyroid carcinoma (MTC) can--even in recurrent cases--only be treated surgically. Therefore, preoperative localization of the tumor is essential. METHODS: From April 1986 through April 1997, 137 patients with MTC were operated on at our clinic. In 22 patients with recurrent tumor which had not been radiologically localized, 28 selective venous catheterizations (SVC) with determination of calcitonin levels were carried out. RESULTS: In 23 examinations a suspected tumor could be identified (nine cervical unilateral, seven mediastinal, four cervical unilateral and mediastinal, one cervical bilateral and mediastinal, one liver, one cervical unilateral and liver). In 18 cases surgery was performed for recurrence (nine cervical revisions, one mediastinal dissection, six cervicomediastinal dissections, two laparotomies). In 15 of 18 cases, tumor tissue was found in the previously suspected area. In ten cases serum calcitonin levels dropped postoperatively by 6%-75%. A normalization of the hormone level was achieved only once by yet another operation. During further follow-up, five of the reoperated patients died from their disease. The other 17 patients are being followed up, whereby calcitonin levels are elevated but there is no clinical or radiological evidence of tumor. CONCLUSIONS: Although in the patient cohort presented a normalization of serum calcitonin could be achieved only once, the authors consider SVC useful because it is the only means of localization of tumor tissue in cases of negative radiologic studies and therefore allows a planned approach to the operation procedure in these cases.

Adolescent↗
PubMed1997

Differential loss of heterozygosity in familial, sporadic, and uremic hyperparathyroidism.

Various genetic loci harboring oncogenes, tumor suppressor genes, and genes for calcium receptors have been implicated in the development of parathyroid tumors. We have carried out loss of heterozygosity (LOH) studies in chromosomes 1p, 1q, 3q, 6q, 11q, 13q, 15q, and X in a total of 89 benign parathyroid tumors. Of these, 28 were sporadic parathyroid adenomas from patients with no family history of the disease, 41 were secondary parathyroid tumors, 5 were from patients with a history of previous irradiation to the neck, 12 were from patients with a family history of hyperparathyroidism, and 3 were parathyroid tumors related to multiple endocrine neoplasia type 1 (MEN1). In addition, we determined the chromosomal localization of a second putative calcium-sensing receptor, CaS, for inclusion in the LOH studies. Based on analysis of somatic cell hybrids and fluorescent in situ hybridization to metaphase chromsomes, the gene for CaS was mapped to chromosomal region 2q21-q22. The following results were obtained from the LOH studies: (1) out of the 24 tumors that showed LOH, only 4 had more than one chromosomal region involved, (2) in the tumors from uremic patients, LOH of chromosome 3q was detected in a subset of the tumors, (3) LOH of the MEN1 region at 11q13 was the most common abnormality found in both MEN1-related and sporadic parathyroid tumours but was not a feature of the other forms of parathyroid tumors, (4) LOH in 1p and 6q was not as frequent as previously reported, and (5) tumor suppressor genes in 1q and X might have played a role, particularly on the X chromosome, in the case of familial parathyroid adenomas. We therefore conclude that the tumorigenesis of familial, sporadic, and uremic hyperparathyroidism involves different genetic triggers in a non-progressive pattern.

Adenoma↗
PubMed1997

[Significance of lymph node metastases of differentiated thyroid gland carcinomas and C-cell carcinomas for prognosis--a meta-analysis].

Surgical therapy of differentiated thyroid cancer (DTC) includes thyroidectomy plus central lymph node dissection and postoperative radioiodine therapy. In cases of lymph node metastasis, T3/T4 tumors and C-cell-carcinoma (after thyroidectomy) uni- or bilateral modified radical lymph node dissection of the neck (neck dissection) and of the mediastinum is recommended. The importance of lymph node metastasis for prognosis of survival in papillary, follicular and C-cell-carcinoma is discussed controversial, however. Even the kind of surgical radicality is questioned. Thus a metaanalysis of 35 studies in 29 independent publications from a pool of 2186 studies was performed. Univariate analysis demonstrates lymph node metastasis as a negative prognostic factor in papillary carcinoma with a 3.25/2.97, in follicular carcinoma with a 7.62/4.0 and in C-cell-carcinoma with a 3.33/3.37 higher probability of mortality 5 and 10 years after operation. Modification of the present surgical therapy can therefore only be accepted after univariate and multivariate analysis of all prognostic factors (age, sex, cell type, tumor extent, lymph node- and distant metastasis) and after it has proven superiority to the present strategy in prospective randomised trials.

Adenocarcinoma, Follicular↗
PubMed1996

[Results of surgical therapy in renal hyperparathyroidism. Follow-up of 143 patients].

Subtotal parathyroidectomy (SPTX) and total parathyroidectomy with autotransplantation (PTX and AT) are now equivalent and challenging surgical procedures, that now involve very low morbidity even in patients with serious secondary illness. In most cases, either brings about a significant amelioration of quality of life. It is rare for the illness to persist after such an operation. In most cases, this is the case only after an inadequate primary operation. An actual recurrence of the illness after at least 6 months is a much more serious problem and cannot usually be attributed to an inadequate operation. Our experience is based on operations performed in 143 patients and a follow-up of up to 8 years. In 68.7% of cases there was a noticeable improvement of bone pain immediately after the operation. This rate fell to 61.5% during subsequent years. Comparable results could not be achieved with any drug therapy. After SPTX the recurrence rate was 4.5%, and after PTX and AT, 5.5%. This is comparable to the results cited in the literature.

Chronic Kidney Disease-Mineral and Bone Disorder↗
PubMed1996

A frequent mutation/polymorphism in tumor suppressor gene INK4B (MTS-2) in papillary and medullary thyroid cancer.

BACKGROUND: Structural genetic changes of tumor suppressor genes MTS-1/INK4A and MTS-2/INK4B were demonstrated in a variety of human cancers but not in thyroid cancer until now. METHODS: Because MTS-2 encodes the tumor suppressor p15, a protein related to the transforming growth factor-beta inhibition of many epithelial cells such as thyrocytes, we investigated MTS-1 and MTS-2 genes in 87 thyroid cancers (29 papillary, 26 follicular, 31 medullary, and 1 anaplastic), 8 goiters, and 38 control DNAs by using a semiquantitative polymerase chain reaction technique. RESULTS: We failed to demonstrate homozygous deletions of MTS-1 and MTS-2 in thyroid tumors, but we demonstrated a highly frequent base pair exchange of the MTS-2 gene 27 codons upstream the 5' end of exon 2. This genetic change formerly described as polymorphism was found to a lesser degree (15%), in control DNA when compared with papillary thyroid cancer and medullary thyroid cancer (35% and 32%, respectively), and it paralleled a higher prevalence of extensive lymph node metastases in thyroid cancer (p < 0.01). In addition, we could demonstrate that genetic changes at site 27 upstream the 5' end of exon 2 were harbored as somatic mutations in 2 of 10 thyroid cancers with simultaneously investigated corresponding control tissue. CONCLUSIONS: We conclude that base pair exchange at this site most likely has biologic importance for the tumor suppressor p15 and may contribute to tumorigenesis and lymphatic spread of differentiated and medullary thyroid cancer.

Adult↗
PubMed1996

Molecular genetics of primary and secondary hyperparathyroidism.

Hyperparathyroidism (HPT) can be caused by solitary parathyroid adenomas and carcinomas, and primary and secondary multiglandular parathyroid disease. Primary HPT is also a feature of several hereditary diseases e.g. multiple endocrine neoplasia type 1 and type 2A (MEN1 and 2A), familial hypocalciuric hyperparathyroidism (FHH), the HPT-jaw tumor syndrome (HPT-JT), and familial isolated HPT. Summarizing data from the literature and our own observations, various genetic abnormalities are observed in the pathogenesis of HPT. These include chromosomal deletions of the MEN1 locus on 11q in sporadic and MEN1 associated primary HPT, of RB1 on 13q in carcinomas, and of the FHH gene located on 3q in sporadic primary and secondary HPT. Genetic material is also lost from chromosomes 1p, 6q, 15q and X suggesting loss of yet unidentified tumor suppressor genes in these regions. In addition the HRPT2 gene on 1q, as well as the proto-oncogenes RET on 10q and PRAD1 on 11q are associated with a subset of parathyroid tumors.

Gene Deletion↗
PubMed1996

Allelic loss of the retinoblastoma tumor suppressor gene: a marker for aggressive parathyroid tumors?

Allelic loss of the retinoblastoma tumor suppressor gene has recently been shown to be highly specific for parathyroid carcinoma. It has been proposed that this genetic abnormality may have diagnostic and prognostic implications for parathyroid carcinoma, but to date no further studies are available to substantiate these findings. In the present study, three cases of atypical recurrent hyperparathyroidism were examined: a patient with parathyroid carcinoma and an autotransplanted adenoma that progressed into carcinoma, a patient with recurrent juvenile hyperparathyroidism, and a patient with severe recurrent secondary hyperparathyroid disease due to rapidly growing autotransplant. Six pairs each of sporadic parathyroid adenoma and secondary parathyroid disease were also studied for comparison. Allelic losses of RB and D13S71 at 13q14 was found in the parathyroid carcinoma and the corresponding autotransplant that had previously been considered benign tissue and in the case of recurrent juvenile hyperparathyroidism, but not in any of the other tumors. Our findings support the findings of the previous study that RB or 13q loss is specific for parathyroid tumors with increased aggressiveness and might be of clinical significance.

Adenoma↗
PubMed1995

[Current aspects of surgery of the parathyroid glands].

Diagnosis and treatment of primary hyperparathyroidism has changed substantially during recent years. Routine serum calcium measurements and development of specific as well as sensitive PTH assays made primary hyperparathyroidism the most prevalent diagnosis of hypercalcaemia in the normal population. With increasing numbers of asymptomatic patients secondary complications are reduced but the demands made on surgeon's technical skill are much higher. In view of our experience in 329 patients with primary hyperparathyroidism during the last six years and a success rate of 98% we refrain from any localisation technique and advocate visualisation of all four glands.

Adenoma↗
PubMed1994

[Surgical strategy in persistence and recurrence in surgery of primary hyperparathyroidism].

Persisting hypercalcemia after surgery for primary hyperparathyroidism is a challenge for the surgeon: once non-parathyroid causes for the hypercalcemia have been excluded the only remaining possible causes are ineffective surgery and a failed surgery. Between 1986 and 1994, 414 patients with primary hyperparathyroidism were operated upon, 32 of whom presented with persisting hypercalcemia; 24 of these patients had their first operation in another hospital. The cause for persisting hypercalcemia was a single adenoma in 27 patients (84%), double adenoma in 2 patients and primary hyperplasia in 2 patients. In 1 patient an unsuccessful revision operation was performed. In 17 patients the parathyroid glands had an atypical position. There were 11 patients who presented with recurrent hyperplasia. The reasons for recurrence were double adenoma in 2 patients and hyperplasia in 8 cases (73%). In 1 patient no pathologic gland was found. Although preoperative localization studies were positive in only 32%, the overall surgical success rate fortunately amounted to a satisfactory 95%.

Adenoma↗
PubMed1993

[Surgical therapy of secondary hyperparathyroidism after kidney transplantation].

Between April 1986 and January 1992, a total of 22 patients with chronic renal failure were operated on for secondary hyperparathyroidism after kidney transplantation, and 21 of these patients were normocalcemic postoperatively. In 1 patient three reductions of autotransplanted parathyroid tissue were performed and this patient was still hypercalcemic postoperatively, with a serum calcium of 2.65 mmol/l. The renal function was not impaired by parathyroidectomy. In 9 of the 22 patients subtotal parathyroidectomy was indicated within 4 months after renal transplantation because of serum calcium levels over 3.0 mmol/l or severe clinical symptoms. Subtotal parathyroidectomy is indicated in patients with secondary hyperparathyroidism after renal transplantation with a serum calcium over 3.0 mmol/l and severe clinical symptoms and also in patients with slightly elevated serum calcium levels after an observation period of up to 12 months.

Adult↗
PubMed1988

[Reinterventions for hyperparathyroidism in multiple endocrine adenopathy].

Six out of a series of 10 patients with hyperparathyroidism associated with an MEA type I syndrome were treated by subtotal parathyroidectomy with resulting normocalcaemia over a follow-up time of one to 7 years. Three patients with repeated previously unsuccessful operations underwent total parathyroidectomy with simultaneous autotransplantation. The first type of operation remains our first choice, while the radical approach with forearm transplantation is reserved only for recurrent surgery for various reasons.

Adult↗
PubMed1988

[Acute abdomen in unrecognized hyperparathyroidism].

The incidence of acute abdomen in patients with unrecognised hyperparathyroidism (HPT) was investigated in 61 patients with primary and 15 patients with secondary HPT, operated on at the Surgical University Department in Düsseldorf between 4/86 and 10/87. In seven patients (9%) an acute abdomen occurred preoperatively (bleeding ulcer n = 3, ulcer perforation n = 1, acute pancreatitis n = 3). Recurrent gastrointestinal disease was observed in 20 of the 76 Patients (28%). The fast and surprising clinical recovery of patients with pancreatitis and HPT after operation of the HPT support the assumption of a causal relation between hyperparathyroidism and pancreatitis. The importance of hypercalcaemia and HPT as causative factors in gastrointestinal ulcers, remains uncertain, however. Possible acute abdominal emergencies in the clinical course of primary hyperparathyroidism support the indication for early operation.

Abdomen, Acute↗
PubMedDate not supplied

West Germany: still an underdeveloped country in the diagnosis and early treatment of primary hyperparathyroidism?

Early diagnosis of asymptomatic patients with primary hyperparathyroidism (primary HPT) has been achieved in Scandinavia, the United States of America, and the United Kingdom during the last 20 years. Comparable results have been reported from some medical centers from West Germany; however, clinical manifestations were pronounced and patient symptoms were high in our population with primary HPT (N = 128) operated on at the University of Düsseldorf from April, 1986 to July, 1989. Only 19 patients (14.8%) were asymptomatic while the others suffered from nephrolithiasis (39%), osteopathy (32%), gastrointestinal disturbances (28.9%), and depression (11.7%). In 46 (35.9%) of our patients, the duration of these clinical symptoms exceeded 10 years, in 27 patients (21%) 15 years, and in 12 patients (9.3%) even 25 years. We, therefore, conclude that primary HPT is still a grossly underdiagnosed illness in parts of West Germany, presently, with patients suffering from severe clinical symptoms for more than 1-2 decades before definitive treatment.

Adult↗