Based on our patient material, preoperative localization of insulinoma was correct with sonography in 13 (61.9%) of 21 patients, with computed tomography in 3 (21.4%) of 14 patients, with computed tomography with bolus injection of contrast medium in 11 (73.3%) of 15 patients, with angiography in 20 (66.6%) of 30 patients, and with percutaneous transhepatic portal vein catheterization with selective measurement of insulin in 10 (76.9%) of 13 patients. Intraoperatively, 40 (95.2%) of 42 insulinomas were palpable and 12 of 16 insulinomas were identified during intraoperative sonography. Although 95.2% of the insulinomas can be palpated, we would support additional diagnostic localization since it may improve the reliability of palpation.

The aim of this study was to clarify the extent of bone mineral deficiency in patients with Klinefelter's syndrome on the premise that testosterone substitution could prevent this deficiency. Bone mineral density was measured by single-photon absorptiometry in 42 patients with Klinefelter's syndrome, (21 patients without therapy, 10 with testosterone substitution before the age of 20 and 11 patients with testosterone substitution beginning after the age of 20). We found significantly lower bone mineral density in patients without therapy and in patients when the therapy began later compared to normal individuals. Patients with early therapy showed a high proportion of normal values of bone mineral density. We found a positive correlation between bone mineral density and plasma testosterone and a negative correlation between plasma testosterone and age for patients without therapy. These findings suggest that low testosterone levels before or during puberty cause inadequate bone development and low bone mineral density in Klinefelter's syndrome. Only early testosterone substitution may prevent bone mineral deficiency. Later substitution no longer affects bone mineral density.

Fifteen patients with a total of 16 islet-cell tumors 7-20 mm in diameter (average, 12 mm) were examined preoperatively by computed tomography (CT) and ultrasound. Seven out of 16 tumors were detected by CT and 9 out of 15 by ultrasound. Marked contrast enhancement was seen on dynamic CT scans following a bolus injection, while a circumscribed, hypoechoic mass was seen on ultrasound. Tumors of the tail of the pancreas and those outside the pancreas were difficult to detect. Ultrasound is recommended as the initial step for locating islet-cell tumors, followed by CT; angiography and transhepatic venous sampling should be restricted to tumors which are not detectable by other methods. Intraoperative ultrasound was successful in 3 patients and may facilitate the operative search.

A total of 42 islet-cell tumors were examined between 1972 and 1984. Problems of localization were only encountered in 31 tumors less than 2 cm in diameter. Of 31 small tumors, 27 were correctly localized using a combined diagnostic approach: ultrasound was successful in 12/20 tumors, CT in 9/21, angiography in 20/31, intraarterial digital subtraction angiography in 1/2, and pancreatic venous sampling in 13/16. The smallest tumor found by ultrasound and CT was 7 mm in diameter. Intraoperative ultrasound demonstrated all 9 insulinomas examined. Currently, the most useful techniques for localizing small islet-cell tumors are ultrasound, CT, and angiography. CT is particularly useful for tumor staging. Improvement of non-invasive diagnostic techniques will obviate the need for transhepatic blood sampling.

We investigated the morphologic structure and fluid content of atherosclerotic specimens of fresh human postmortem artery segments before and after application of a pressure of 5 atmospheres simulated by a weight of 5 kg per 1 cm2. After applying pressure in nonorganized atheromata, we noticed a marked reduction in thickness while in fibrotic atheromata we observed only smaller differences in thickness. Reduction in fluid content was significantly more pronounced in nonorganized atheromatous tissue. Reduction in thickness was closely related to reduction in weight (i e, fluid content). The time of pressure application necessary to achieve the optimal result averaged 60 sec. The conclusions drawn from these experiments were incorporated into clinical application of coronary angioplasty. Prolonged balloon inflation was applied to the last 400 out of a total of 600 coronary angioplasty procedures, performed between October 1977 and October 1983. Stenoses not sufficiently responsive to balloon inflation periods of 5-10 sec were exposed to periods of 60 sec (30-120 sec). The number of "non dilatable" stenoses was 15% with the standard short pressure procedure, but only 5% with the prolonged pressure application. No serious complications related to prolonged pressure application were observed. Thus, from experimental data and clinical experience the application of longer pressure periods appears justified and beneficial.

Gynaecomastia, or enlargement of the male breast may result from various endocrine dysfunctions and often reflects ectopic production of substances such as hCG and estradiol. We report on the case of a 30 year old man who presented with gynaecomastia and elevated plasma levels of hCG, estradiol and testosterone. As a result of several diagnostic procedures such as selective venous sampling and magnetic resonance tomography (MRT), a hCG producing tumor of the upper lobe of the left lung was found. This hormonal overproduction induced an enhanced secretion of estradiol and testosterone in the testicular tissue. Histology revealed a giant cell carcinoma with positive immunostaining for hCG. This case report further underlines the necessity of an intensive search for ectopic beta-hCG production due to malignant tumours, in particular in the adult.

Of 29 patients examined operation revealed a malignant tumor in 9 and a benign insulinoma in 18, 2 insulinomas were not found. The problems of preoperative tumor localization were limited to small insulinomas (size 7-35 mm). Ultrasound detected all of 3 insulinomas as low echogenic structures (size 7, 8, 17 mm). Computed tomography demonstrated 4 of 5 insulinomas (size 7, 8, 15, 17 mm) due to contrast enhancement following bolus injection. Arteriography localized 12 of 18 insulinomas preoperatively and 14 of 18 retrospectively. Selective transhepatic venous sampling for insulin assay identified 7 of 8 tumors. Real-time ultrasound and dynamic CT are promising in the diagnostics of insulinomas over 7 mm and should precede arteriography. Selective transhepatic venous sampling as the last diagnostic step is a major procedure and most specific, but not always without problems in interpretation.

Contradictory statements exist regarding the necessity of a preoperative localization in organic hyperinsulinism. In a general inquiry of all surgical clinics with more than 100 beds in the Federal Republic of Germany, we wanted to know the diagnostic procedures and the results in cases of organic hyperinsulinism. Questionnaires were sent to 404 clinics, and 266 (65.8%) responded. In 1988, 108 patients with organic hyperinsulinism were operated on in the Federal Republic of Germany. Two thirds of all clinics used intraoperative sonography, nevertheless nearly all of them additionally performed preoperative localization. With the use of intraoperative sonography, 96.5% of all insulinomas could be found, compared to only 91.3% without it. These results show the importance of intraoperative sonography, as well as the value of the preoperative localization.