Clincical Analysis Of Pituitary ACTH Adenoma With Normal CT Or MRI And Occult Functioning Insulinoma

Part one: A clinical analysis of pituitary ACTH adenomawith normal pituitary CT or MRIObjectives: to understand the clinical characteristics of pituitary ACTHadenoma with normal pituitary CT or MRI.Methods: Collecting and analyzing all of the medical materials ofhospitalized patients with Cushing disease (CD) and ectopic ACTHsyndrome (EAS) in West China Hospital (WCH) from 1996 to 2006. Acomparison was made between pituitary ACTH adenoma with positive andnormal pituitary CT or MRI, between pituitary ACTH adenoma with normalpituitary CT or MRI and EAS. Data analysis was conducted by packagesSPSS 11.0 and Revman 4.2.9.Results: During the 11 years from 1996 to 2006, 43 patients with CD hadbeen admitted in WCH and 16.3% of them showed a normal pituitaryimaging in CT or MRI. In the same decade, 8 patients with EAS had beenadmitted. No difference had been found between the 2 groups of CD, but itseems that patients with normal pituitary CT or MRI had a higher femalepercentage and were older when diagnosed of CD than patients with positivepituitary CT or MRI. For patients with normal pituitary CT or MRI, the average time from adrenalectomy to a positive finding in pituitary MRI wasabout 4.57 years. After adrenalectomy, the risk of pigmentation was 83.3%and the cortisol level would decease about 55.6%. The average BMI andcourse in CD patients with normal pituitary CT or MRI were 23.75kg/m~2 and2.81 years respectively, while the EAS had an average BMI of 20.20 kg/m~2and average course of 0.22 year. EAS had a higher average blood cortisollevel, 24hUFC, ACTH and higher risk of hypokalemia than CD patients withnormal pituitary CT or MRI but less symptoms and signs ofhypercortisolemia. Tumors from lung and mediastinum and malignant tumormade up of 75% in all EAS respectively.Conclusions: 16.3% of CD showed a normal CT or MRI pituitary imagingand compared to those with positive pituitary imaging, there was nodifference in clinical manifestations and biochemical results. Removal of theadrenal glands is an obligate choice if pituitary-directed treatments failed orare inexpedient and/or steroid synthesis inhibitors yield poor results.Compared with CD patients with normal pituitary CT or MRI, patients withEAS had a broader extent of age, shorter course, higher levels of cortisol andACTH, and little signs of hypercortisolemia.Part two: A clinical analysis of occult pancreatic imaging offunctioning insulinomaObjectives: to understand the clinical characteristics of occult pancreaticimaging of functioning insulinoma. Methods: Collecting and analyzing all of the medical materials ofhospitalized patients with insulinoma in West China Hospital from 1996 to2006. A clinical comparison was made between occult and positive pancreaticimaging insulinoma. Data analysis was conducted by packages SPSS 11.0 andRevman 4.2.9.Results: During the 11 years from 1996 to 2006, 24 patients with insulinomahad been admitted and occult pancreatic imaging insulinoma made up of16.7% in all insulinoma. The misdiagnosis rate of insulinoma was about37.5%. No difference had been found between the 2 groups of insulinoma,except for that patients with occult pancreatic imaging insulinoma got abigger BMI and lower FBG. The risk of severe hypoglycemia in insulinomawas 75%. The mislocalization rate of CT, MRI, DSA was 15.4%, 50.0%,50.0 % respectively. The most insulinoma frequent came up in caudapancreas.Conclusions: The false negative rate and mislocalization rate of routinelyused imaging methods in insulinoma were high and surgical explorationshould be indicated when more than 3 times of hypoglycemia had happenedand insulin level was abnormally high and meanwhile hypoglycemia due toinsulin autoimmune syndrome can be excluded.