Selective venous sampling in the differential diagnosis of ACTH-dependent Cushing's syndrome.

Bilateral simultaneous inferior petrosal sinus sampling, associated with the oCRH stimulation test (100 micrograms i.v. as a bolus) was performed in 22 patients with Cushing's syndrome and no signs of pituitary abnormalities. Catheters were inserted into both femoral veins. More than one site in the superior and inferior vena cava was sampled before reaching the inferior petrosal sinuses. Blood samples for ACTH and beta-endorphin were gently aspirated from both petrosal sinuses and from a peripheral vein simultaneously. Blood was drawn at 0, 5, 10 and 15 min after oCRH injection. Seventeen of 22 patients showed an ipsilateral to peripheral vein ratio higher than 1.5, and 12 patients showed a lateralization of ACTH levels after oCRH stimulation. Seventeen patients underwent transsphenoidal pituitary surgery. Nine patients had a pituitary adenoma at the expected side; 1 at the contralateral side, while in 2 it was central. Three of 4 patients in whom the ipsilateral/peripheral ratio was less than 1.5 had the highest ACTH levels at the superior or inferior vena cava, not responsive to oCRH stimulation. One of these had a mediastinal and one a pulmonary mass. The third one, with an occult ectopic source, is still under investigation. At immunohistochemical and biological in vitro studies, both tumors were shown to secrete ACTH. In 13 patients in whom both beta-endorphin and ACTH measurements were performed, these hormones showed similar patterns of response. In conclusion, simultaneous bilateral petrosal sinus catheterization is a useful tool in the differential diagnosis of Cushing's syndrome as concerning pituitary and ectopic forms.(ABSTRACT TRUNCATED AT 250 WORDS)     

Diagnostic imaging of differentiated thyroid carcinoma

The role of diagnostic imaging in differentiated thyroid carcinoma is analyzed. 99mTc-pertechnetate 123I and 131I scintigraphy allows the evaluation of nodules with their differentiation in cold (hypofunctioning) and hot (functionally autonomous) nodules; thyroid carcinomas are cold nodules even if most of them are benign. On sonography thyroid nodules are well visualized with the definition of their site, number, size (not very useful parameters for the diagnosis of malignancy), echoic structure, and vascularization on color Doppler. The sonographic findings suggestive of differentiated thyroid carcinoma are: solid and hypoechoic structure, irregular ill-defined margins, absent or discontinuous peripheral ring, microcalcification, intranodular vascularization, local lymphadenopathies. These findings are characteristic but not pathognomonic, mostly for papillary carcinoma, while in the frequently isoechoic follicular carcinoma microcalcification and lymph node metastases are rare. Only the finding, although rather infrequent, of the dissemination to adjacent structures (muscles and vessels) is a definite indication for malignancy of a thyroid nodule. Color Doppler sonography plays a major role in the postoperative staging and follow-up, in combination with thyroglobulin determination and 131I whole body scintigraphy and it allows the detection of local and/or laterocervical lymph node recurrence. The most typical sonographic findings of metastatic lymphadenopathy are the roundish shape (length/anteroposterior diameter ratio-L/A < 1.5), not visible or displaced nodal hilum, thickened cortical layer with echoic structure similar to that of thyroid parenchyma, at times with microcalcification, cortical vascularization and dismantled angioarchitecture. CT and MRI are occasionally more useful to evaluate the substernal or retrosternal extension of voluminous thyroid masses and to identify local or distant metastases.     

Hypercreatininemia and hyperglycemia: diabetic nephropathy or "inverted peritoneal auto-dialysis"?

We describe a case of 51-year-old male with fever, abdominal pain and inguino-scrotal hernia. Laboratory examination revealed hypercreatininemia and hyperglycemia, firstly interpreted as diabetic nephropathy. US and CT scan showed a hernia of the bladder into the scrotum. Surgery revealed multiple bladder perforations with peritoneal diffusion of urine. So, hypercreatininemia was caused by peritoneal reabsorption of urea and creatinine, a condition that may be described as "inverted peritoneal auto-dialysis". Surgical reposition and repairment of the bladder led to rapid normalization of serum urea and creatinine. Discharged diagnosis was intraperitoneal rupture of inguino-scrotal hernia of the bladder in patient with recent onset of diabetes mellitus.     

Local-regional staging of endometrial carcinoma: role of MR imaging in surgical planning

PURPOSE: To assess magnetic resonance (MR) imaging in depicting the depth of myometrial infiltration, cervical invasion, and presence of enlarged lymph nodes in patients with endometrial adenocarcinoma compared with surgicopathologic findings. MATERIALS AND METHODS: Thirty-seven consecutive patients with endometrial carcinoma were included in this prospective study. All patients underwent MR imaging and surgery. Qualitative image analysis included the depth of myometrial infiltration, infiltration of the uterine cervix, and presence of enlarged lymph nodes. Quantitative image analysis included tumor and myometrium contrast-to-noise ratios during different phases of dynamic imaging. MR imaging findings were compared with surgicopathologic findings. Sensitivity, specificity, diagnostic accuracy, and positive and negative predictive values of MR imaging in depicting myometrial and cervical infiltration and in lymph node assessment were calculated. RESULTS: Respective sensitivity, specificity, diagnostic accuracy, and positive and negative predictive values in assessing myometrial infiltration were 87%, 91%, 89%, 87%, and 91%; those for cervical infiltration, 80%, 96%, 92%, 89%, and 93%; and those for lymph node assessment, 50%, 95%, 90%, 50%, and 95%. There was significant agreement between MR imaging and surgicopathologic findings in assessment of myometrial invasion (P <.001). Myometrial and cervical invasion and lymph node enlargement were correctly assessed with MR imaging in 28 (76%) of 37 patients. Quantitative analysis showed a significant improvement in tumor and myometrium contrast-to-noise ratios during the equilibrium phase compared with the arterial and precontrast phases (P <.001). CONCLUSION: MR imaging coupled with contrast material-enhanced dynamic MR imaging is highly accurate in local-regional staging of endometrial carcinoma; more challenging is the assessment of pelvic and lumboaortic lymph nodes.     

Inhibition of pituitary beta-endorphin by ACTH and glucocorticoids

beta-Endorphin and ACTH are secreted concomitantly in baseline conditions and in response to physiological and pharmacological stimuli. However, few and contradictory data are available on their feedback inhibition mechanisms. To investigate this aspect, the effects of exogenous ACTH1-24 and glucocorticoids on endogenous ACTH1-39 and beta-endorphin were tested in 18 patients with Addison's disease. Two main experimental protocols were employed: (1) 7 patients were given ACTH1-24 50 micrograms as an intravenous bolus followed by a 50-micrograms infusion in 90 min. Blood samples for beta-endorphin, ACTH and cortisol were obtained at 0, 15, 30, 45, 60, 90, 120 min. Six other patients were given oCRH 100 micrograms i.v. plus ACTH1-24, as described above. (2) In 5 other patients, hydrocortisone 37.5 mg was administered i.v. in 90 min. Blood samples for beta-endorphin, ACTH and cortisol were drawn at 0, 15, 30, 45, 60, 90, 120 min. One week later, the same patients were given oCRH 100 micrograms i.v. and hydrocortisone 37.5 mg, as described above. ACTH1-24 administration caused a significant (p less than 0.01) decrease in endogenous ACTH but not in beta-endorphin. oCRH injection significantly stimulated both ACTH and beta-endorphin. The response of both ACTH and beta-endorphin was inhibited by exogenous ACTH1-24. There was a potent inhibition by hydrocortisone on both basal and stimulated beta-endorphin, confirming that the feedback mechanism of glucocorticoids concomitantly inhibits ACTH and beta-endorphin. On the other hand, only CRH-stimulated but not basal secretion of beta-endorphin seems affected by ACTH ultrashort feedback, suggesting an intrapituitary regulation.     

Ultrasonographic patterns in hepatic hemangiomas

Twenty-one cases of hepatic hemangioma were examined by ultrasound, and three main sonographic patterns were identified. In 14 cases hyperechoic focal areas were observed, in five cases larger hemangiomas exhibited a complex pattern, and in two cases hemangiomas appeared as rounded sonolucent areas with distal enhancement mimicking cysts. Hemangiomas may have significantly variable ultrasonographic features. According to the authors' experience, only in cases of hyperechoic well-defined lesions in asymptomatic patients can a definite diagnosis of hemangioma be made.     

Sonographic diagnosis of distal biceps tendon rupture: a prospective study of 25 cases.

OBJECTIVE: To describe the sonographic findings of distal biceps tendon ruptures and to assess the accuracy of the technique. METHODS: Twenty-five patients with clinically indicated distal biceps tendon ruptures were prospectively studied by sonography. Five patients also underwent magnetic resonance imaging. Surgical confirmation was obtained in 14 patients. RESULTS: Seventeen complete tendon ruptures and 3 partial tears were correctly shown by sonography; 1 complete rupture was incorrectly shown as a partial tear by sonography. Sonographic features of complete rupture were absence of tendon in the expected location, fluid collection in a typical tendon gap, and a mass in the antecubital fossa. Sonographic features of incomplete rupture were intratendinous hypoechogenicity and tendon thinning. Peritendinous fluid was found in complete and incomplete ruptures. CONCLUSIONS: In distal biceps tendon ruptures, sonography is a cost-effective method that can confirm the clinical indications with good accuracy and can show tendon lesions when the clinical indications are low.     

Biliodigestive anastomoses on echography. The normal and pathological aspects]

The normal and pathological US features of different types of bilioenterostomy (hepaticojejunostomy, choledochoduodenostomy, polyductal bilioenteric anastomosis) are described, as observed in a prospective study of 27 patients, for a total number of 35 (18 normal and 17 abnormal) examinations. For 20 patients with hepaticojejunostomy, the bilioenteric anastomosis was identified on 13/13 normal examinations and 10/12 pathological examinations. For 2 patients with choledochoduodenostomy, the bilioenteric anastomosis was identified on 2/2 examinations. For 5 patients with polyductal bilioenteric anastomosis (each patient having 2 or 3 anastomoses), all surgical anastomoses were separately identified on 6/8 examinations; as for the remaining 2 patients, 2/3 and 1/3 anastomoses were seen. An abnormal condition was correctly recognized in all the 11 patients with local disease (lithiasis and benign biliary stricture, 2 patients; benign biliary stricture, 5 patients; primary cholangiocarcinoma, 1 patient; recurrent malignancy, 3 patients); in 1 patient, parenchymal and biliary abnormalities due to vascular obstruction were misinterpreted as a result of benign stricture. US can demonstrate the surgical anastomoses between the resected common bile duct or second order intrahepatic ducts and the jejunal loop, with typical features according to the type of surgery performed. Knowledge of such normal appearances after bilioenteric surgery is mandatory in order to detect and correctly evaluate such possible abnormalities at this site as lithiasis and benign or malignant strictures.