A pitfall in diagnosing Cushing's disease: ectopic ACTH-producing pituitary adenoma in the sphenoid sinus.

PURPOSE: To show a rare case of Cushing's disease and possible cause of failed transsphenoidal surgery. METHOD: We report on a 50-year-old woman suffering from ACTH-dependent Cushing's syndrome. Endocrinological work-up including low-dose/high-dose dexamethasone test (Liddle-test) and CRH test were clearly compatible with pituitary origin. Although an MRI showed no pituitary tumor, CRH-stimulated petrosal sinus sampling revealed a significant central-peripheral gradient in ACTH concentrations, rendering Cushing's disease very likely. The patient underwent transsphenoidal surgery with negative exploration of the pituitary gland. After intraoperative re-evaluation of the preoperative MRI, a "polyp" at the bottom of the sphenoid sinus was identified. The intraoperative microscopic aspect as well as instantaneous sections and cytology of a biopsy confirmed an adenoma, which was then removed. Histological analysis demonstrated an ACTH-producing pituitary adenoma adjacent to respiratory mucous membrane consisting of ciliated epithelium with submucous connective tissue. Postoperatively, ACTH concentrations were decreased and intermittent hydrocortisone substitution treatment was initiated. At the 3-month follow up, Cushing's stigmata were found to be alleviated and the hydrocortisone dosage could be reduced. CONCLUSION: Ectopic pituitary adenoma tissue causing Cushing's disease is extremely rare but a potential cause for surgical failure or re-evaluation.

131I-metaiodobenzylguanidine--a new agent for scintigraphic imaging and treatment of pheochromocytoma.

In 91 patients with a suspicion of pheochromocytoma 96 scintigraphies with 131I-metaiodobenzylguanidine were performed. The distribution of this radiopharmaceutical agent was studied. In about 71% we found uptake in the liver, in about 20% in the spleen and in about 6% in the gastrointestinal tract. In 13% of our patients a normal tracer uptake in the adrenal medulla was observed. In 23 patients adrenal or extra-adrenal lesion(s) were localized correctly, whereas one false-positive and one false-negative scintigramme was obtained. The 131I-MIBG imaging of adrenal and extra-adrenal, benign and malignant pheochromocytomas and adrenomedullary hyperplasia is highly specific. In the treatment of pheochromocytomas more experience is needed to present final results, but especially in malignant pheochromocytomas 131I-MIBG therapy may be useful.

Hemofiltration in myoglobinuric acute renal failure.

The frequency of myoglobinuric renal failure is estimated between 8 and 20%. Despite early onset of therapy often the use of renal substitution by hemodialysis or hemofiltration is required. This study of the clinical course of nine patients with myoglobinuric acute renal failure reveals continuous arterio-venous hemofiltration (CAVH) to have an effective clearance for myoglobin. Thus, the time until recovery of renal function as well as the frequency of secondary complications in rhabdomyolysis induced acute renal failure can be distinctly reduced.

Double-phase Tc-99m MIBI scintigraphy in secondary hyperparathyroidism relapsing after parathyroidectomy and removal of a parathyroid autograft.

A 53-year-old woman with chronic renal failure had secondary hyperparathyroidism relapsing after undergoing a second parathyroidectomy and excision of an autologous parathyroid graft that had been implanted after her first parathyroidectomy. Double-phase scintigraphy with Tc-99m MIBI disclosed pathologic MIBI uptake in the right anterior thorax where the parathyroid transplant had been placed. Histopathologic examination of three nodules excised from this region yielded hyperplastic parathyroid tissue. This case report further illustrates the value of double-phase Tc-99m MIBI scintigraphy in atypical cases of hyperparathyroidism.

[Rare variants and unusual course of Cushing's syndrome]. / Seltene Varianten und Verlaufsformen des Cushing-Syndroms.

Cushing's syndrome is a rarely observed disease with a poor prognosis when not treated appropriately. Knowledge of clinical features of the different forms of the disease together with a specific and subtle method of cortisol detection is indispensable for an early out-patient diagnostic program. In this study the characteristic features of the rare benign and malignant forms of Cushing's syndrome are presented in typical case-reports. As it has been proven in clinical experience, the necessary diagnostic measures for clarification of the syndrome consists of only few methods reliable concerning their diagnostic validity. The success of any curative treatment of the benign forms or any palliative measure of the malignant forms essentially depends on early diagnosis and differentiation of the various appearances of Cushing's disease.

Diagnosis and treatment of phaeochromocytoma with 131I-metaiodobenzylguanidine.

131I-meta-iodobenzylguanidine scintigraphy was performed in 30 patients with biochemically proven catecholamine excess. In all but two patients scintigraphy localised the lesion(s) correctly. In high concentrations the same radiopharmaceutical agent was used for treatment of 3 patients with a malignant multilocular and one patient with an intra-adrenal unilocular phaeochromocytoma. The results confirm that 131I-meta-iodobenzylguanidine is suitable for scintigraphic imaging of intra-adrenal and extra-adrenal phaeochromocytomas, both benign and malignant, as well as for treatment of malignant phaeochromocytoma.

[Therapy of primary aldosteronism with trilostane]. / Die Behandlung des primären Aldosteronismus mit Trilostan.

Trilostane is a competitive inhibitor of the 3 beta-hydroxysteroid dehydrogenase enzyme system localized in the adrenal cortex and in the gonads. This inhibitor reduces the production of cortisol, aldosterone and androstendione. Trilostane was used for the treatment of 3 male and 2 female patients with primary aldosteronism, two of whom had an adenoma of the adrenal cortex and three bilateral adrenal hyperplasia. After a 12 weeks' treatment with trilostane (average dosage 288 mg/day) normalization of plasma aldosterone (from 368 to 35.1 pg/ml) was achieved. Average blood pressure had almost normalized (147/98 mm Hg) after the treatment period. However, in one patient no, or only a minor, reduction in blood pressure was observed during trilostane and even during captopril and minoxidil administration. Except slight diarrhea in 2 cases, which did not require cessation of trilostane medication, there were no further side effects. After 12 weeks' treatment the average serum cortisol was in the lower normal range. It is concluded from these results that trilostane is an effective therapeutic agent in primary aldosteronism, especially where there is no indication for surgery.

Scintigraphy in pheochromocytoma.

In four patients with pheochromocytoma, scintigraphy with 131I-meta-iodobenzylguanidine was performed to localize hyperfunctioning adrenergic tissue. In three patients unilateral adrenal pheochromocytoma was found, whereas one patient with a malignant pheochromocytoma showed multilocular dissemination. The results document that scintigraphy with 131I-meta-iodobenzylguanidine seems to be a safe and reliable method of detecting adrenal and extra-adrenal pheochromocytomas, both benign and malignant.

[Hereditary spherocytosis and polycythemia]. / Hereditäre Sphärozytose und Polyzythämie.

A case of hereditary spherocytosis is described in a casuistic report where the clinical picture of polycythaemia appeared 5 years after a successful splenectomy. The possibilities of a coincidence of diseases, a postsplenectomy reaction or a genuine myeloproliferative syndrome as the cause underlying a secondary disease are discussed.

Localization procedures in pheochromocytoma and neuroblastoma.

Localization procedures are required in catecholamine-producing tumors after clinical and biochemical confirmation. Computed tomography, ultrasound and/or 131I-metaiodobenzylguanidine (131I-MIBG) scintigraphy was performed in patients with pheochromocytoma, neuroblastoma and metastases of carcinoid tumors. Whereas computed tomography and ultrasound reflect morphological abnormalities, adrenomedullary scintigraphy depends on hormonal activity and other factors. 131I-MIBG scintigraphy has the advantage of detecting extraadrenal, multilocular and malignant pheochromocytomas. Especially small lesions and tumor tissue in bone marrow in children with neuroblastoma can be visualized more easily.

[Specific scintigraphy in pheochromocytoma]. / Spezifische SzintigraPhie beim phäochromozytom.

In 5 patients with pheochromocytoma and 1 patient with a pheochromoblastoma, 131I-meta-iodobenzylguanidine was used to localize hyperfunktioning adrenergic tissue. Except in one patient, a correct localization of the tumors was obtained. Three patients had an intraadrenal pheochromocytoma of the left adrenal gland, 1 patient a retropancreatic pheochromoblastoma and 1 patient multilocular pheochromocytoma with tumors in both renal hili, in the supraclavicular region and in the bones. In one patient with a pheochromocytoma of the right adrenal, no clearcut visualization of the tumor could be observed. In this patient, in contrast to the other examinations, a specific activity of 2 mCi/mg benzylguanidine was used (0.2 mCi/mg benzylguanidine in the other patients). Thus, the amount of benzylguanidine given for each scan was 10fold higher in the patients with a correct localization. The present results document the claim that scintigraphy with 131I-benzylguanidine is a safe and reliable method of detecting both benign and malignant adrenal and extra-adrenal pheochromocytoma. To separate the pheochromocytoma from the adjacent tissue, additional computed tomography should be performed.

Primary aldosteronism: treatment with trilostane.

Trilostane, an inhibitor of the 3 beta-hydroxysteroid dehydrogenase enzyme system of steroid biosynthesis, was applied to 18 patients with primary aldosteronism (9 patients with adrenal adenoma, 9 patients with bilateral adrenal hyperplasia) for 12 weeks. A marked decrease in plasma aldosterone was observed during therapy combined with a reduction in blood pressure and a rise in serum potassium levels. Except for slight diarrhea in 4 patients, which did not require cessation of trilostane medication, no further side effects were observed. Trilostane proved to be an effective inhibitor of aldosterone biosynthesis and was found useful in the treatment of primary aldosteronism both in patients with adrenal adenoma and in those with bilateral adrenal hyperplasia.

Scintigraphic localization of phaeochromocytomas.

131I-meta-iodobenzylguanidine scanning was performed in 14 patients with phaeochromocytomas. In all but one patient scintigraphy successfully localized the lesion(s). The results confirm that scintigraphic imaging with 131I-meta-iodo-benzylguanidine, a noninvasive method, is a valid and reliable procedure for imaging and localization of adrenal and extra-adrenal phaeochromocytomas, both benign and malignant.