Paul C. Carpenter

The Cushing Syndrome Induced by Bronchial Carcinoid Tumors

OBJECTIVES To define the clinical spectrum of bronchial carcinoid tumors in patients presenting with the Cushing syndrome, to evaluate the role of chest radiographs and computed tomography in their diagnosis, to review the characteristic histologic features, and to determine patient outcome. DESIGN Retrospective analysis of consecutive patients. SETTING A referral-based medical center. PATIENTS Fifteen consecutive patients with the Cushing syndrome evaluated at the Mayo Clinic with histologically proven bronchial carcinoid tumors. MEASUREMENTS Clinical, radiographic, and histologic features. RESULTS The Cushing syndrome was the initial clinical presentation, and bronchial carcinoid tumors were found later in all 15 patients. The diagnosis of carcinoid tumor was proved histologically in all cases. Ten biopsies showed typical carcinoid tumors, three were histologically atypical, and three were metastatic. Corticotropin was detected by immunostaining in seven of these tumors. Biochemical analysis showed marked elevations of circulating corticotropin with a mean serum value of 156 +/- 58 pmol/L (normal, 4 to 22 pmol/L). Additional clinical features included hypokalemia in six patients and glucocorticoid response to either high-dose dexamethasone or metyrapone in 6 of 13. These hormonally active carcinoid tumors were frequently radiographically occult, with 10 of 15 patients initially having normal chest radiographs. Computed tomography was successful in locating carcinoid tumors in five patients with negative chest radiographs evaluated after 1980. All five remaining patients with normal chest radiographs evaluated before 1980 eventually developed nodular lesions on standard chest radiography from 1 to 10 years later. Ten patients achieved complete remission and two patients, partial remission of the Cushing syndrome after surgical resection. Three patients continued to have symptomatic glucocorticoid excess due to metastatic disease. CONCLUSIONS Although uncommon, the Cushing syndrome may be the initial clinical manifestation of an otherwise indolent bronchial carcinoid tumor. Radiographic imaging of occult lesions can be successfully accomplished with computed tomography. Surgical resection is curative in most patients with this disorder.

Lymphocytic Hypophysitis with Isolated Corticotropin Deficiency

In a 32-year-old woman, acquired, isolated corticotropin deficiency resulted from postpartum lymphocytic hypophysitis. The literature suggests that lymphocytic hypophysitis may cause acquired deficiencies of anterior, and possibly posterior, pituitary hormones. Immunologic evaluation of our patient failed to uncover anticorticotroph antibodies. Prompt recognition of this potentially fatal condition is important because of the availability of effective treatment.

Ectopic ACTH syndrome. Diagnostic and therapeutic aspects.

Twenty-five patients were identified with non-pituitary, nonadrenal ACTH-secreting tumors (bronchial carcinoid, bronchial small cell carcinoma, pancreatic islet cell carcinoma, medullary thyroid carcinoma, thymic carcinoids, metastatic adenocarcinoma, and pancreatic cystadenoma). Clinical features were weakness, hypertension, cushingoid appearance, peripheral edema, personality disorders, and hyperpigmentation. Biochemical features were a markedly increased urinary free cortisol level (all patients), hypokalemia (71 percent of patients), and an elevated ACTH level (72 percent of patients). Surgical therapy consisted of bilateral total adrenalectomy (56 percent of patients). Twelve percent underwent transsphenoidal hypophysectomy and 36 percent had excision of their tumor. No surgical therapy was undertaken in 28 percent. Bilateral total adrenalectomy in patients with a slow-growing malignancy or an unknown tumor secreting ACTH is beneficial in relieving symptoms and prolonging life. Excision of nonmalignant ACTH-producing tumors yields an excellent long-term prognosis.

Stereotactic radiosurgery as an alternative to fractionated radiotherapy for patients with recurrent or residual nonfunctioning pituitary adenomas.

OBJECTIVETo evaluate tumor control rates and complications after stereotactic radiosurgery for patients with nonfunctioning pituitary adenomas. METHODSBetween 1992 and 2000, 33 patients underwent radiosurgery for treatment of nonfunctioning pituitary adenomas. Thirty-two patients (97%) had undergone one or more previous tumor resections. Twenty-two patients (67%) had enlarging tumors before radiosurgery. The median tumor margin dose was 16 Gy (range, 12–20 Gy). The median follow-up period after radiosurgery was 43 months (range, 16–106 mo). RESULTSTumor size decreased for 16 patients, remained unchanged for 16 patients, and increased for 1 patient. The actuarial tumor growth control rates at 2 and 5 years after radiosurgery were 97%. No patient demonstrated any decline in visual function. Five of 18 patients (28%) with anterior pituitary function before radiosurgery developed new deficits, at a median of 24 months after radiosurgery. The actuarial risks of developing new anterior pituitary deficits were 18 and 41% at 2 and 5 years, respectively. No patient developed diabetes insipidus. CONCLUSIONStereotactic radiosurgery safely provides a high tumor control rate for patients with recurrent or residual nonfunctioning pituitary adenomas. However, despite encouraging early results, more long-term information is needed to determine whether radiosurgery is associated with lower risks of new endocrine deficits and radiation-induced neoplasms, compared with fractionated radiotherapy.

Surgery for Cushing’s Syndrome: An Historical Review and Recent Ten-year Experience

BackgroundCushing’s syndrome (CS), due to multiple etiologies, is a disorder associated with the ravages of cortisol excess. The purpose of this review article is to provide a historical synopsis of surgery for CS, review a recent 10-year period of operative management at a tertiary care facility, and to outline a practical approach to diagnosis and management.Materials and MethodsFrom 1996 to 2005, 298 patients underwent 322 operative procedures for CS at Mayo Clinic, Rochester, Minnesota. A retrospective chart review was carried out. Data was gathered regarding demographics, preoperative assessment, procedures performed, and outcomes. Data are presented as counts and percentages. Five-year survival rates were calculated where applicable by the Kaplan-Meier method. Statistical analysis was carried out with SAS, version 9 (SAS Institute, Inc., Cary, NC).ResultsTwo-hundred thirty-one patients (78%) had ACTH-dependent CS and 67 patients (22%) had ACTH-independent CS. One-hundred ninety-six patients (66%) had pituitary-dependent CS and 35 patients (12%) had ectopic ACTH syndrome. Fifty-four patients (18%) had cortisol-secreting adenomas, 10 patients (3%) had cortisol-producing adrenocortical carcinomas, and 1% had other causes. Cure rates for first time pituitary operations (transsphenoidal, sublabial, and endonasal) were 80% and 55% for reoperations. Most benign adrenal processes could be managed laparoscopically. Five-year survival rates (all causes) were 90%, 51%, and 23% for adrenocortical adenomas, ectopic ACTH syndrome, and adrenocortical carcinomas, respectively.ConclusionsSurgery for CS is highly successful for pituitary-dependent CS and most ACTH-independent adrenal causes. Bilateral total adrenalectomy can also provide effective palliation from the ravages of hypercortisolism in patients with ectopic ACTH syndrome and for those who have failed transsphenoidal surgery. Unfortunately, to date, adrenocortical carcinomas are rarely cured. Future successes with this disease will likely depend on a better understanding of tumor biology, more effective adjuvant therapies and earlier detection. Clearly, IPSS, advances in cross-sectional imaging, along with developments in transsphenoidal and laparoscopic surgery, have had the greatest impact on today’s management of the complex patient with CS.

ADRENAL SENSITIVITY TO ANGIOTENSIN II AND UNDISCOVERED ALDOSTERONE STIMULATING FACTORS IN HYPERTENSION

Abstract We have determined that the adrenal glands of patients with the syndromes of low-renin essential hypertension and idiopathic hyperaldosteronism are abnormally sensitive to the steroidogenic effect of angiotensin II. The mechanism of this heightened responsiveness to angiotensin II is unknown but may be due to the bilateral adrenal hyperplasia present in many patients with these low-renin hypertension syndromes. We have found that metoclopramide, a dopamine antagonist, causes three-fold increases in levels of plasma aldosterone in normal subjects. These increases could not be accounted for by changes in plasma renin activity, ACTH or potassium. Metoclopramide does not stimulate bovine adrenal glomerulosa cells to produce aldosterone in vitro , suggesting that it stimulates the secretion of aldosterone in vivo indirectly, by increasing the levels or the activity of an undefined aldosterone stimulating factor. We have also found that human urine, after partial purification, stimulates bovine adrenal glomerulosa cells to produce aldosterone in vitro . Urine samples from patients with low-renin essential hypertension or idiopathic hyperaldosteronism have more stimulating activity than urine samples from normal subjects. These preliminary findings support the hypothesis that excessive production of an undefined aldosterone stimulating factor may be the basic abnormality in some cases of idiopathic hyperaldosteronism and low-renin essential hypertension.

Adrenal surgery for hypercortisolism— surgical aspects

BACKGROUND Patients with endogenous hypercortisolism are thought to be at high risk for adrenalectomy and may experience significant postoperative surgical mortality/morbidity. METHODS From 1981 through 1991, 91 patients underwent adrenal resection for endogenous hypercortisolism. Causes were adrenal-dependent Cushings syndrome (50%), pituitary-dependent Cushings syndrome (27%), and an ectopic adrenocorticotropic hormone-secreting tumor (23%). Causes of adrenal-dependent Cushings syndrome were adrenocortical adenoma (72%), bilateral nodular hyperplasia (20%), and adrenocortical carcinoma (8%). Comparative mean length of hospitalization for patients undergoing unilateral anterior versus posterior approach was 8 versus 6 days, and bilateral anterior versus posterior was 11 versus 6 days. RESULTS Operative mortality was 2.6%. Only one patient had a wound infection, and no patient had either a venous thrombosis or a pulmonary embolism. Delayed wound healing occurred in three patients. CONCLUSIONS (1) Adrenal surgery can be performed today with low morbidity/mortality. (2) Although there is an effect of hypercortisolism on wound healing, infection, diabetes, hypertension, coronary artery disease, and pulmonary embolism, it was possible to perform adrenalectomy surgically with acceptable morbidity and mortality. (3) These results may serve as a standard against which laparoscopic adrenalectomy may be compared.

Ectopic secretion of a growth hormone-releasing factor: Report of a case of acromegaly with bronchial carcinoid tumor

Rarely, acromegaly is produced by neuroendocrine neoplasms elaborating a substance similar to or identical with growth hormone-releasing factor. This report reviews the cases described to date and presents the clinicopathologic features of a patient with acromegaly, mild sellar enlargement, and elevated growth hormone levels associated with a large bronchial carcinoid tumor. Normalization of serum growth hormone levels and regression of acromegaly followed resection of the bronchial tumor, which was shown, by bioassay and immunocytochemistry, to contain a growth hormone-releasing factor.

Speech recognition as a transcription aid: a randomized comparison with standard transcription.

OBJECTIVE Speech recognition promises to reduce information entry costs for clinical information systems. It is most likely to be accepted across an organization if physicians can dictate without concerning themselves with real-time recognition and editing; assistants can then edit and process the computer-generated document. Our objective was to evaluate the use of speech-recognition technology in a randomized controlled trial using our institutional infrastructure. DESIGN Clinical note dictation from physicians in two specialty divisions was randomized to either a standard transcription process or a speech-recognition process. Secretaries and transcriptionists also were assigned randomly to each of these processes. MEASUREMENTS The duration of each dictation was measured. The amount of time spent processing a dictation to yield a finished document also was measured. Secretarial and transcriptionist productivity, defined as hours of secretary work per minute of dictation processed, was determined for speech recognition and standard transcription. RESULTS Secretaries in the endocrinology division were 87.3% (confidence interval, 83.3%, 92.3%) as productive with the speech-recognition technology as implemented in this study as they were using standard transcription. Psychiatry transcriptionists and secretaries were similarly less productive. Author, secretary, and type of clinical note were significant (p < 0.05) predictors of productivity. CONCLUSION When implemented in an organization with an existing document-processing infrastructure (which included training and interfaces of the speech-recognition editor with the existing document entry application), speech recognition did not improve the productivity of secretaries or transcriptionists.

Sublabial Transseptal vs Transnasal Combined Endoscopic Microsurgery in Patients With Cushing Disease and MRI-Depicted Microadenomas

OBJECTIVE To assess whether the type of surgical approach to the sella (sublabial transseptal vs transnasal) affects surgical outcome among patients with Cushing disease. PARTICIPANTS AND METHODS Both procedures were performed at our institution from January 1, 1995, through January 31, 2003. From a total of 106 patients with Cushing disease who had had surgery, we identified 42 adults undergoing an initial surgery, with microadenoma (<1 cm) determined by magnetic resonance imaging and a minimal follow-up of 3 months. RESULTS We identified 21 patients (4 male, 17 female) for sublabial transseptal transsphenoidal microsurgery. Mean+/-SD age was 45.0+/-12.9 years (range, 27.0-69.0 years); median duration of symptoms was 2.5 years (range, 1.5-7.5 years). Median follow-up was 1.0 year (range, 0.3-11.0 years). We identified another 21 patients (5 male, 16 female) for endoscopic transsphenoidal microsurgery whose mean+/-SD age was 43.8+/-14.1 years (range, 19.0-70.0 years); median duration of symptoms was 2.4 years (range, 0.2-6.0 years). Median follow-up was 2.5 years (range, 0.3-8.7 years). Complications (cerebrospinal fluid leak and transient diabetes insipidus) and cure (86% initial cure; 76% relapse-included cure) were equivalent between the 2 procedures. However, the endoscopic approach was associated with shorter anesthesia time, less blood loss, and shorter hospital stays. CONCLUSION The endoscopic transnasal surgical approach led to shorter total anesthesia time, less blood loss, and shorter hospital stay when compared with the sublabial transseptal approach. However, we found no difference between the 2 surgical procedures with respect to cure or complications, suggesting that outcome is more closely related to the experience of the operating team.