Transsphenoidal microsurgical management of Cushing's disease. Report of 100 cases

The development of transsphenoidal microsurgery and the refinement of endocrinological and radiological diagnostic procedures have afforded therapeutic options appropriate to the individual case in patients with hypercortisolism. The present series of 100 cases is derived from 104 patients with the diagnosis of Cushing's disease who underwent transsphenoidal pituitary exploration between 1974 and 1981. Excluding four patients in whom the pituitary gland was not exposed because of intraoperative technical difficulties, an overall cure rate of 78% was achieved. Among 71 patients with tumors confined to the sella turcica, 87% had correction of their hypercortisolism, 11% represented therapeutic failures, and one patient had tumor recurrence. In contrast, among 25 patients with extrasellar extension, correction of hypercortisolism was achieved in only 48%, 40% failed to respond, and 12% of the patients had recurrence. Four patients who failed to respond to total hypophysectomy have ectopic sources of adenocorticotropic hormone. The results indicate that transsphenoidal microsurgical exploration for a basophilic adenoma is the procedure of choice in adults and children with Cushing's disease. The diagnostic and surgical approach to these tumors, as well as pitfalls in the transsphenoidal treatment of Cushing's disease, are discussed.

The metabolic clearance rate and origin of plasma dihydrotestosterone in man and its conversion to the 5-alpha-androstanediols

Dihydrotestosterone metabolism was studied with a constant infusion technique in three men, three women, five hirsute women, and four estrogen-treated hirsute women. The mean dihydrotestosterone metabolic clearance rate was higher in men (336 liters/24 hr per m(2) [range, 239-448]) than in women (153 liters/24 hr per m(2) [range, 108-184]). The metabolic clearance rates in hirsute patients were intermediate between those men and women and were decreased by estrogen treatment. These observations demonstrate similarities in the metabolic rates of testosterone and dihydrotestosterone. The conversion of plasma testosterone and androstenedione to dihydrotestosterone was studied in men and hirsute women. Approximately 4 and 2% of plasma testosterone and androstenedione, respectively, were converted to plasma dihydrotestosterone in both groups. From these observations it was determined that a major fraction of plasma dihydrotestosterone was derived from these plasma precursors rather than from glandular secretion. Both 5alpha-androstan-3alpha,17beta-diol (3alpha-diol) and 5alpha-androstan-3beta,17beta-diol (3beta-diol) were identified in plasma during dihydrotestosterone and testosterone infusions. The conversion ratio of dihydrotestosterone to 3alpha-diol (C(BB) (DHT-3alpha)) was greater than the conversion ratio to the 3beta-isomer (C(BB) (DTH-3beta)) in all the patients studied. Both C(BB) (DHT-3alpha) and C(BB) (DHT-3beta) were higher in men (mean values of 0.151 [range, 0.110-0.222] and 0..031 [range, 0.022-0.042]) than in women (means of 0.044 [range, 0.037-0.048] and 0.012 [range 0.010-0.013]). A smaller fraction of testosterone was converted to 3alpha-diol and 3beta-diol.

Results of transsphenoidal hypophysectomy in 52 dogs with pituitary-dependent hyperadrenocorticism

OBJECTIVE

To evaluate microsurgical transsphenoidal hypophysectomy in dogs with pituitary-dependent hyperadrenocorticism (PDH).

STUDY DESIGN

Prospective study to evaluate the results (survival and disease-free interval, remission, recurrence) and complications of microsurgical transsphenoidal hypophysectomy by clinical follow-up, computed tomography (CT), and urinary corticoid-to-creatinine (C/C) ratios in dogs with PDH. The effect of surgical experience was investigated by comparing results of hypophysectomy cases 1 through 26 and 27 through 52.

ANIMALS OR SAMPLE POPULATION

52 dogs with PDH.

RESULTS

Preoperative CT enabled accurate assessment of pituitary size (24 nonenlarged and 28 enlarged) and localization relative to intraoperative anatomic landmarks. Treatment failures included procedure-related mortalities (five dogs) and incomplete hypophysectomies (four dogs). The 1-year estimated survival rate was 84% (95% confidence interval [CI], 71% to 92%). The 2-year estimated survival rate was 80% (95% CI, 65% to 90%). In 43 dogs, the hyperadrenocorticism went into remission. Hyperadrenocorticism recurred in five dogs. The 1-year estimated relapse-free fraction was 92% (95% CI, 76% to 97%). The main complications were transient, mild, postoperative hypernatremia; transient reduction or cessation of tear production (25 eyes in 18 dogs); permanent (five dogs) or prolonged (nine dogs) diabetes insipidus; and secondary hypothyroidism. Normal tear production had resumed in all but one case after a median period of 10 weeks. In the second case series (27 through 52), the hospitalization period was shorter, the number of dry eyes fewer, the survival fraction greater, and the postoperative mortality lower than in the first series. In 15 dogs in which remission was obtained, postoperative CT images suggested the presence of small pituitary remnants; in 1 of these, hyperadrenocorticism recurred. In 46 dogs, the histological diagnosis was pituitary adenoma.

CONCLUSIONS

Microsurgical transsphenoidal hypophysectomy in dogs with PDH is an effective method of treatment in specialized veterinary institutions having access to advanced pituitary imaging techniques. Postoperative CT findings do not correlate well with remission or subsequent recurrence of hyperadrenocorticism.

CLINICAL RELEVANCE

The neurosurgeon performing hypophysectomies must master a learning curve and must be familiar with the most frequent complications of the operation to recognize them as early as possible and to treat them immediately and effectively. Urinary C/C ratios are sensitive indicators for the assessment of remission and recurrence of hyperadrenocorticism.

Serum cortisol response to transsphenoidal surgery for Cushing disease

OBJECT

Transsphenoidal surgery remains the optimal treatment for Cushing disease, but the definitions of surgical cure and failure remain debatable. In this study the authors evaluated serum cortisol levels in patients before and after they underwent transsphenoidal surgery to elucidate the patterns of cortisol decrease and the optimal time and criteria for determining surgically induced remission.

METHODS

Twenty-seven patients were evaluated throughout an 8-month period. Serum cortisol levels were obtained before surgery and at 6-hour intervals postoperatively. No exogenous steroid medications were administered until after cortisol sampling was discontinued, following diagnosis of remission. Twenty-one (78%) of 27 cases were labeled initial surgically induced remissions. Twenty-two (81%) of 27 cases were deemed surgically induced remissions at follow-up examination. Following surgery, initial remissions and failures demonstrated divergent patterns of cortisol levels. No patient whose condition was deemed an initial surgically induced remission has experienced definitive relapse of disease since discharge. One patient whose condition was initially deemed a surgical failure, eventually was found to exhibit surgically induced remission without further intervention.

CONCLUSIONS

Given such findings, exogenous steroid medications do not appear to be required for patients until after the determination of remission. During the 1st postoperative day, there is a time period during which serum cortisol values significantly differ between the categories of surgically induced remissions and surgical failures. Surgically induced remissions were identified when postoperative values of cortisol were lower than preoperative midnight levels and when absolute values of cortisol were less than 10 microg/dl. In a small proportion of patients remission on a delayed basis may also be demonstrated. These data allow for a simple and rapid determination of postoperative remission in patients undergoing transsphenoidal surgery for Cushing disease.

Transsphenoidal hypophysectomy for treatment of pituitary-dependent hyperadrenocorticism in 7 cats

OBJECTIVE

Evaluation of microsurgical transsphenoidal hypophysectomy for the treatment of pituitary-dependent hyperadrenocorticism (PDH) in cats.

STUDY DESIGN

Prospective clinical study.

ANIMALS OR SAMPLE POPULATION

Seven cats with PDH.

METHODS

Urinary cortisol/creatinine ratios, pituitary-adrenocortical function tests, and computed tomography (CT) were performed on 7 cats that presented with a provisional diagnosis of hyperadrenocorticism. All cats underwent microsurgical transsphenoidal hypophysectomy with histologic examination of the excised specimen. Follow-up consisted of clinical evaluation, repeat adrenocortical function testing, and CT.

RESULTS

Four cats had concurrent diabetes mellitus. In all cats, the urinary cortisol/creatinine (C/C) ratios were elevated. The dexamethasone screening test showed that 2 cats did not meet the criterion for hyperadrenocorticism. The response of the cats' plasma concentrations of cortisol and adrenocorticotrophic hormone to a high dose of dexamethasone varied from very sensitive to completely dexamethasone resistant. Basal plasma alpha-melanocyte-stimulating hormone concentrations were elevated in 2 cats with a pars intermedia adenoma and in 3 cats with an adenoma that originated from the anterior lobe. Preoperative CT enabled accurate assessment of pituitary size (5 nonenlarged pituitaries with a height <4 mm and 2 enlarged pituitaries with a height >5 mm) and localization relative to intraoperative anatomic landmarks. Two cats died within 4 weeks after surgery of a nonrelated disease. In the remaining 5 cats, the hyperadrenocorticism went into both clinical and biochemical remission. Hyperadrenocorticism recurred in 1 cat after 19 months, but no other therapy was given and the cat died at home 28 months after surgery. CT evaluation of this cat had identified pituitary remnants 6 weeks after surgery. The main postoperative complications were oronasal fistula (1 cat), complete dehiscence of the soft palate (1 cat), and transient reduction of tear production (1 cat). One cat died at 6 months (undefined anemia), and another cat at 8 months (recurrent nose and middle ear infection secondary to soft palate dehiscence) after surgery. In the surviving 2 cats, the remission periods at the time of writing were 46 and 15 months. In the 2 cats with sufficient follow-up time, the concurrent diabetes mellitus disappeared, ie, insulin treatment could be discontinued at 4 weeks and 5 months after hypophysectomy. In all 7 cats, the histologic diagnosis was pituitary adenoma.

CONCLUSIONS

Microsurgical transsphenoidal hypophysectomy is an effective method of treatment for feline PDH in specialized veterinary institutions having access to advanced pituitary imaging techniques. Concurrent diabetes mellitus is usually reversible after hypophysectomy. Thorough presurgical screening for coexisting diseases is imperative.

CLINICAL RELEVANCE

PDH in cats can be effectively treated by hypophysectomy. The neurosurgeon performing hypophysectomy must master a learning curve and must be familiar with the most frequent complications of the operation to treat them immediately and effectively. Urinary C/C ratios are sensitive indicators for the assessment of remission and recurrence of hyperadrenocorticism.

Transsphenoidal hypophysectomy in beagle dogs: evaluation of a microsurgical technique

OBJECTIVE

Assessment of a microsurgical technique for transsphenoidal hypophysectomy in dogs.

STUDY DESIGN

Prospective study using physical examination, pituitary function testing, computed tomography (CT), and histological examination at autopsy.

ANIMALS OR SAMPLE POPULATION

Eight laboratory beagle dogs.

METHODS

Pituitary function was assessed before and at 10 weeks after hypophysectomy by combined administration of four releasing hormones (anterior pituitary), administration of haloperidol (pars intermedia), and infusion of hypertonic saline (posterior pituitary).

RESULTS

CT imaging enabled accurate preoperative localization of the pituitary. Appropriate positioning and surgical technique facilitated exposure of the pituitary and its extraction without hemorrhage. Postoperative recovery was generally uncomplicated. None of the eight dogs had somatotropic, gonadotropic, lactotropic, melanotropic, or posterior pituitary responses to stimulation at 10 weeks after hypophysectomy. Four dogs (ACTH nonresponders) also had no corticotropic response and four (ACTH responders) had small but significant responses in the combined anterior pituitary function test. Adrenocortical atrophy was more pronounced in the ACTH nonresponders than in the responders. No residual pituitary tissue was found along the ventral hypothalamic diencephalon but nests of pituitary cells were found embedded in fibrous tissue in the sella turcica.

CONCLUSIONS

The surgical technique proved to be safe and effective. Microscopic nests of pituitary cells in the sella turcica may be responsible for residual corticotropic response to hypophysiotropic stimulation after hypophysectomy.

CLINICAL RELEVANCE

The surgical technique may be used in the treatment of dogs with pituitary-dependent hyperadrenocorticism. The corticotropic response is the most sensitive criterion in assessing completeness of hypophysectomy in dogs.

Laparoscopic adrenalectomy

Using the transperitoneal, laparoscopic approach, we performed 67 successful adrenalectomies between June 1993 and July 1995 at Greenslopes Hospital, Brisbane. There were 30 women and 37 men. Syndromes of primary adrenal hormone overproduction--primary aldosteronism (n = 52), pheochromocytoma (n = 6), and hypercortisolism (n = 1)--were present in 59 patients and apparently nonfunctioning adrenal tumors (of which one was malignant) in 8 patients. There was a significant difference in the time of operation between patients weighing < 80 kg and those weighing > 80 kg. Operations on males were slower than those on females, possibly explained by males being significantly heavier. Left-sided tumors outnumbered right-sided tumors; removal of right-sided adrenals took, on average, longer, but this difference was not significant.

Diagnosis and treatment of functioning and nonfunctioning adrenocortical neoplasms including incidentalomas

The most important functional tumors of the adrenal cortex are those that secrete cortisol or aldosterone in excess. Biochemical testing when appropriately utilized can diagnose and differentiate the cause of Cushing's syndrome, and when an adrenal adenoma is found, surgical excision is curative. The diagnosis and surgical treatment of primary aldosteronism are straightforward today, and localization of the usual small cortical tumor producing the syndrome can be achieved by CT and NP-59 scanning or selective venous assays. Adrenocortical carcinomas are relatively rare, are usually incurable when diagnosed, and are an important consideration in the incidentally discovered adrenal mass found by CT scanning.

Results of adrenalectomy in 36 dogs with hyperadrenocorticism caused by adreno-cortical tumour

A total of 38 adrenocortical tumours were removed from 36 dogs with hyperadrenocorticism. The surgical approach was by way of a unilateral flank laparotomy (32 dogs; 14 left and 18 right), a bilateral flank laparotomy (3 dogs) or a midline celiotomy (1 dog). Two dogs were euthanized during surgery because their tumours could not be resected. Eight dogs died from post-operative complications. Pancreatic necrosis with peritonitis was the most common cause of death. Eight of the 26 dogs that survived had signs of recurrence of hyperadrenocorticism. Unsuppressible hyperadrenocorticism was found in four dogs; one dog had probably pre-existent pituitary-dependent hyperadrenocorticism, and adrenocortical function could not be re-examined in the remaining three dogs. Among the 37 tumours examined microscopically expansion of neoplastic tissue into blood vessels was found in 22 of them. Four adrenal glands with adrenocortical tumours also contained phaeochromocytomas. Necropsy was performed in eight dogs. Metastases were found in the lungs of two dogs and in the lungs and liver in one dog. In combination with the data of previous reports, it is suggested that histological findings in surgery specimens are not good predictors for the clinical outcome.

Clinical aspects and surgical treatment of hyperadrenocorticism in the domestic ferret: 94 cases (1994-1996)

The signalment, clinical findings, laboratory values, and histopathological results of 96 ferrets with signs (i.e., bilaterally symmetrical alopecia, return to male sexual behavior, or an enlarged vulva) suggestive of hyperadrenocorticism were evaluated retrospectively. Of these 96 ferrets, 94 (98%) were diagnosed with hyperadrenocorticism histologically. Treatment consisted of unilateral adrenalectomy for unilateral tumors (84%) and subtotal bilateral adrenalectomy for bilateral adrenal tumors (16%). The histopathological diagnosis included nodular hyperplasia (56%), adrenocortical carcinoma (26%), and adrenocortical adenoma (16%). Common concurrent diseases included splenomegaly (87%), islet-cell tumor (27%), and cardiomyopathy (10%).

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 Cushing's syndrome (50%), pituitary-dependent Cushing's syndrome (27%), and an ectopic adrenocorticotropic hormone-secreting tumor (23%). Causes of adrenal-dependent Cushing's 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.

Dynamic Computed Tomography of the Pituitary Gland in Dogs with Pituitary-Dependent Hyperadrenocorticism

Dynamic computed tomography (CT) of the pituitary gland was performed in 55 dogs with pituitary-dependent hyperadrenocorticism (PDH) that underwent transsphenoidal hypophysectomy. On routine contrast-enhanced CT images, microadenomas of the pituitary gland often are indistinguishable from nontumorous pituitary tissue because of isoattenuation. Dynamic CT may allow visualization of these adenomas. The changes in the contrast-enhancement pattern of the pituitary during dynamic CT in 55 dogs with PDH were correlated with surgical and histopathologic findings. In 36 dogs, dynamic CT identified distinct contrast enhancement of the neurohypophysis (pituitary flush). In 24 dogs, this pituitary flush was displaced, which indicated the presence of an adenoma. This observation was confirmed surgically and histopathologically in 18 of the 24 dogs. In 19 dogs, there was a diffusely abnormal contrast-enhancement pattern. CT findings agreed with surgical findings in 13 of these dogs and with histopathologic findings in all 19 dogs. It is concluded that a dynamic series of scans should be included in the CT protocol of the pituitary gland in dogs with PDH because it allows for identification of an adenoma or a diffusely abnormal pituitary gland.

Successful treatment of acromegaly in a diabetic cat with transsphenoidal hypophysectomy

PATIENT AND SURGICAL TREATMENT: An 11-year-old, castrated male cat was referred for insulin-resistant diabetes mellitus. It had a ravenous appetite, increased body weight, polyuria/polydipsia and a dull hair coat. The cat was receiving 25 IU insulin four times daily but blood glucose concentrations remained elevated. Plasma concentrations of growth hormone (GH) (51 microg/l, reference range 0.8-7.2 microg/l) and insulin-like growth factor 1 (IGF-1) (3871 microg/l, reference range 39-590 microg/l) were highly elevated, whereas those of alpha-melanocyte-stimulating hormone, adrenocorticotropic hormone and cortisol were normal. Computed tomography revealed a thick palatum molle and an enlarged pituitary gland, indicating a pituitary neoplasm. Microsurgical transsphenoidal hypophysectomy was performed and microscopic examination of the surgical specimen revealed an acidophilic, infiltrative pituitary adenoma that showed positive immunostaining for GH.

OUTCOME

The clinical signs resolved and 3 weeks after surgery the cat no longer required insulin administration. One year after hypophysectomy the plasma concentrations of GH and IGF-1 were 2.4 microg/l and 113 microg/l, respectively.

PRACTICAL RELEVANCE

This is the first report detailing transsphenoidal hypophysectomy as a feasible and effective treatment for feline acromegaly due to a pituitary somatotroph adenoma. Moreover, in this patient, concurrent insulin-resistant diabetes mellitus resolved completely. The surgery is discussed in the context of human and other feline therapies for acromegaly.

Role and operative risk of bilateral adrenalectomy in hypercortisolism

Transsphenoidal pituitary surgery has radically modified the management of pituitary-dependent hypercortisolism (Cushing's disease). Bilateral adrenalectomy may, however, represent the ultimate treatment in some cases of hypercortisolism. In the present study we report our experience of bilateral adrenalectomy in 82 patients operated on during the last 15 years. The causes of hypercortisolism were Cushing's disease (n = 78), ectopic ACTH syndrome (n = 3), and primary adrenocortical nodular dysplasia (Carney-Meador syndrome) (n = 1). Before operation 37% of the patients had severe symptoms of hypercortisolism. A bilateral posterior approach was undertaken in 58 patients, whereas 18 patients had an anterior transabdominal approach and 6 patients a laparoscopic approach. There were two operative deaths (2.4%). Postoperative complications occurred mostly in cases of advanced disease and were observed in 14 patients (17%), among whom 4 had severe complications. At long-term follow-up, one recurrence of hypercortisolism and 12 Nelson syndromes (15%) were observed. In conclusion, bilateral adrenalectomy carries an acceptable operative risk, and we recommend bilateral adrenalectomy rather than long-term suppressive therapy in patients requiring prompt and definitive control of their hypercortisolism or after pituitary surgery failure.

Hyperadrenocorticism treated with metyrapone followed by bilateral adrenalectomy in a cat

A 6-year-old spayed female cat was evaluated for uncontrolled diabetes mellitus and poor hair coat. Clinicopathologic abnormalities included high serum activity of liver enzymes, hyperglycemia, hypercholesterolemia, glucosuria, and an exaggerated response to ACTH stimulation. Abdominal ultrasonography revealed large adrenal glands. Hyperadrenocorticism was diagnosed. Treatment for a facial abscess was instituted along with administration of metyrapone for hyperadrenocorticism. After stabilization, bilateral adrenalectomy was performed. The cat recovered without complications and has remained clinically normal for 5 months with treatment of desoxycorticosterone pivalate and prednisone. Treatment with metyrapone appeared to stabilize the cat metabolically and clinically prior to surgery.

Residual pituitary function after transsphenoidal hypophysectomy in dogs with pituitary-dependent hyperadrenocorticism

Pituitary function was assessed before and after transsphenoidal hypophysectomy in 39 dogs with pituitary-dependent hyperadrenocorticism (PDH). Anterior pituitary function was investigated using combined administration of four hypophysiotropic releasing hormones (corticotropin-releasing hormone (CRH), GHRH, GnRH, and TRH) with measurements of ACTH, cortisol, GH, LH, prolactin (PRL), and TSH Pars intermedia function was assessed by measurements of basal plasma alpha-MSH concentrations and adrenocortical function by baseline urinary corticoid/creatinine ratios. At eight weeks after hypophysectomy basal plasma ACTH, cortisol, GH, LH, PRL, and TSH concentrations were significantly lower than before surgery. In seven dogs with elevated alpha-MSH concentrations, the values returned to the normal level after surgery. In the combined anterior pituitary function test there were no plasma GH, LH, PRL, and TSH responses to stimulation, whereas plasma ACTH and cortisol responses were small but significant. Remission of hyperadrenocorticism was obtained in 35 dogs and recurrences occurred in 3 of these within 16 months postoperatively. At 8 weeks after hypophysectomy, these 3 dogs were not discernible, with respect to residual pituitary and adrenocortical function, from the 32 dogs with persisting remission. Urinary corticoid/creatinine ratios in the latter group of dogs did not increase during 22 months after hypophysectomy. In contrast to the presurgical findings, at 8 weeks after hypophysectomy there were significant positive correlations between baseline urinary corticoid/creatinine ratios and basal levels and responses for ACTH, indicating return to normal function of the pituitary-adrenocortical axis. It is concluded that among the adenohypophyseal cells present in the sella turcica after hypophysectomy, the corticotropes have a distinct behavior. Much more so than the other cell types, the unaffected corticotropes tend to remain functional, or a repressed reserve fraction of corticotropes may become functional. This may be due to the removal of the hypothalamic influence of a postulated corticotropin-release inhibiting factor or a diminished inhibitory influence of a postulated paracrine factor. The corticotropes may maintain normocorticism, but may also lead to mild recurrence after relatively long periods of remission.

The Role of Adrenal Venous Sampling in the Surgical Management of Primary Aldosteronism

OBJECTIVE

Primary aldosteronism is the most common endocrine form of secondary hypertension, but no single test or imaging method always identifies it. Identification of a unilateral overproduction of aldosterone due to Conn's adenoma or unilateral hyperplasia is of utmost importance to the surgeon.

MATERIALS AND METHODS

We reviewed our experience with primary aldosteronism in 46 consecutive patients who had undergone adrenalectomy at the Surgical Pathology Institute, University of Padua since 1993. All the patients underwent a CT scan. Adrenal venous sampling was performed in those patients with negative or equivocal findings on imaging studies.

RESULTS

Computed tomography was non-contributory in 12 patients and frankly misleading in 2 patients, demonstrating a probable mass lesion in the contralateral but not in the ipsilateral adrenal. Eighteen patients had selective venous sampling that was successful in altering the management of 14 cases. Eleven patients who biochemically had an adrenal adenoma, had normal/equivocal CT, while the remaining 3 had bilateral or contralateral adrenal masses. Venous sampling localized aldosterone secretion and an adenoma, less than 1 cm in diameter, was removed, curing their hypertension. Eleven patients were treated by open adrenalectomy and 35 by the lateral transperitoneal laparoscopic approach. Histological examination revealed 45 Conn's adenomas, of which 13 had a diameter of less than 1 cm (range 0.3-0.8), and 1 case of nodular hyperplasia.

CONCLUSIONS

Patients who have equivocal or unexpected CT findings should proceed to hormonal localization. Adrenal venous sampling is essential in patients with equivocal CT scans to avoid unnecessary and inappropriate adrenalectomy.

Intravesicular administration of clotrimazole for treatment of candiduria in a cat with diabetes mellitus

A 12-year-old spayed female domestic longhair cat developed fungal cystitis (Candida sp). The cat had a history of chronic diabetes mellitus, hyperadrenocorticism, and bacterial cystitis caused by Escherichia coli. Antifungal agents (itraconazole and fluconazole) were administered orally without noticeable effect on the candiduria. Because of the ineffectiveness of these treatments, intravesicular administration of 1% clotrimazole solution was performed weekly for 3 treatments. Complete resolution of urinary candidiasis was detected after the third infusion. Intravesicular administration of clotrimazole solution appears to be a safe and effective treatment of fungal cystitis in cats.

Efficacy of transsphenoidal hypophysectomy in treatment of dogs with pituitary-dependent hyperadrenocorticism

The long-term survival, disease-free fractions, and the complications of hypophysectomy in 150 dogs with pituitary-dependent hyperadrenocorticism (PDH) were examined in a prospective study. Long-term survival and disease-free fractions in relation to pituitary size were analyzed by the Kaplan-Meijer estimate procedure. The 1-, 2-, 3-, and 4-year estimated survival rates were 84% (95% confidence interval [CI], 76-89%), 76% (67-83%), 72% (62-79%), and 68% (55-77%), respectively. Treatment failures included procedure-related mortalities (12 dogs) and incomplete hypophysectomies (9 dogs). The 1-, 2-, 3-, and 4-year estimated relapse-free fractions were 88% (CI: 80-93%), 75% (64-83%), 66% (54-76%), and 58% (45-70%), respectively. Postoperative reduction of tear production (58 eyes in 47 dogs) was often reversible but remained low until death in 11 eyes of 10 dogs. Central diabetes insipidus (CDI) occurred more frequently (62%) in dogs with enlarged pituitaries than in dogs with nonenlarged pituitaries (44%). Survival and disease-free fractions after hypophysectomy were markedly higher in dogs with nonenlarged pituitaries than in dogs with enlarged pituitaries. Transsphenoidal hypophysectomy is an effective treatment for PDH in dogs. The survival and disease-free fractions after hypophysectomy decrease and the incidence of CDI increases with increasing pituitary size. Therefore, early diagnosis of PDH is important and transsphenoidal hypophysectomy is expected to have the best outcome when used as primary treatment for dogs with nonenlarged or moderately enlarged pituitaries.

Hyperadrenalism in childhood and adolescence

Hyperadrenalism in childhood and adolescence has unique features that influence diagnosis and management. We reviewed our experience with 18 patients, ranging in age from 18 months to 18 years. Nine had bilateral adrenal hyperplasia, eight had adrenal neoplasms, and one had micronodular hyperplasia. Patients with congenital adrenal hyperplasia and hyperaldosteronism were excluded. Six patients with Cushing's disease diagnosed in earlier years were treated by total adrenalectomy and recently two patients underwent transsphenoidal removal of pituitary tumors. Bilateral adrenalectomy was carried out in one patient with micronodular hyperplasia and in a second because of elevated adrenocorticotrophic hormone (ACTH) levels from an undefined source. Eight patients had adrenal neoplasms, including five adenomas and three carcinomas. We found no reliable criteria to differentiate before surgery between adrenal adenomas and adrenal carcinomas. The most recognizable characteristic of malignancy was tumor size, specifically weight greater than 75 gms. Of the three patients with adrenal carcinoma, one expired 20 months after adrenalectomy and 8 months after receiving palliative partial hepatectomy for liver metastasis. Two patients are well with normal growth and development at 11 and 20 years following adrenalectomy. With the exception of one patient who died 6 years after surgery from a glioblastoma multiforme, all patients with adrenal adenomas are well. Eight patients underwent bilateral adrenalectomy for hypercortisolism. Five of the six who have reached their adult stature are significantly stunted. Four of six patients with Cushing's disease, treated by total adrenalectomy, have developed Nelson's syndrome at 2, 6, 10, and 12 years after surgery. Of the two patients undergoing transsphenoidal surgery, one had recurrent disease at 2 years and was treated by pituitary irradiation with recovery. The patients undergoing adrenalectomy for micronodular hyperplasia and ectopic ACTH are well at 2 and 4 years, respectively. Cushing's disease in children and adolescents is best treated by transsphenoidal removal of the pituitary adenoma. Adrenalectomy, once the most accepted approach, plays a secondary role and is indicated primarily in micronodular adrenal hyperplasia, in patients with ectopic ACTH production of an undefined source, and in recurrent Cushing's disease following prior pituitary irradiation. The high incidence of Nelson's syndrome in children treated by adrenalectomy mandates that patients at risk be monitored lifelong for the progression of a pituitary tumor.(ABSTRACT TRUNCATED AT 400 WORDS)

[Use of cabergoline in persisting Cushing's disease]

Cabergoline is a dopaminergic agonist with demonstrated efficiency of for the treatment of prolactin-secreting pituitary tumors. It has also been reported effective for patients with hypercortisolism uncontrolled by conventional therapies. We describe the use of cabergoline in three patients with Cushing's disease, one of them presenting a silent ACTH-secreting pituitary tumor. Those patients underwent surgery and only one has been treated with radiation therapy. However persisting hypercortisolism motivated the use of cabergoline. We describe a decrease or a normalization in hypercortisolism; for one of the subjects, tumor growth seemed to be stopped. While cabergoline can induce a suppression of cortisol secretion or a corticotroph tumor shrinkage, the sites of action remain unclear.

Hormonal characteristics of primary aldosteronism due to unilateral adrenal hyperplasia

A case of unilateral adrenocortical hyperplasia is presented. A 46-year-old woman with a 7-year history of hypertension and a 1-year-history of hypokalemia was diagnosed with primary aldosteronism. Computed tomography, magnetic resonance imaging, venous sampling and adosterol scintigraphy exhibited a functioning left adrenal mass. The plasma aldosterone concentration increased markedly when furosemide with upright posture and either captopril or adrenocorticotropin were administered. Plasma renin activity was suppressed below the detectable range. Aldosterone secretion displayed a circadian rhythm and was not suppressed by dexamethasone administration. The resected left adrenal mass was pathologically diagnosed as adrenocortical nodular hyperplasia. Unilateral adrenal hyperplasia involving the zona glomerulosa rarely has been reported, with varying and incompletely characterized hormonal characteristics. This case report and literature review suggest unilateral adrenal hyperplasia as a rare cause of hyperaldosteronism with characteristics intermediate between idiopathic hyperaldosteronism and aldosterone-producing adrenocortical adenoma, resembling the functional features of the adenoma more closely.

Plasma profiles of adrenocorticotropic hormone, cortisol, alpha-melanocyte-stimulating hormone, and growth hormone in dogs with pituitary-dependent hyperadrenocorticism before and after hypophysectomy

The 6-h plasma profiles of adrenocorticotropic hormone (ACTH), cortisol, alpha-melanocyte-stimulating hormone (alpha-MSH), and GH were studied in 17 dogs with pituitary-dependent hyperadrenocorticism (PDH) before and after hypophysectomy. The aim of the study was to investigate the relation between the hormone profile characteristics and recurrence of PDH after surgery. The hormones were secreted in a pulsatile fashion. The basal plasma cortisol concentration and area under the curve (AUC) for cortisol were significantly higher in the PDH cases than in eight controls. The characteristics of the plasma profiles of ACTH and alpha-MSH were not significantly different between the PDH cases and the controls. In the PDH cases, less GH was secreted in pulses than in the controls, but the difference was not significant. The basal plasma cortisol concentration, the AUC for ACTH and cortisol, and the pulse frequency of ACTH and cortisol decreased significantly after hypophysectomy for the group of PDH cases. The basal plasma concentrations of ACTH and alpha-MSH, the AUC for alpha-MSH, and the characteristics of the plasma GH profiles of the PDH cases remained unchanged after hypophysectomy. No pulses of alpha-MSH were observed after hypophysectomy. The co-occurrence between the ACTH and cortisol pulses decreased significantly with hypophysectomy. The postoperative pulse frequency of ACTH was the only characteristic with predictive value for the recurrence of PDH after hypophysectomy. The results of this study demonstrate that ACTH, cortisol, alpha-MSH, and GH are secreted in a pulsatile fashion in dogs with PDH. Hypophysectomy effectively reduces the secretion of ACTH and cortisol. The presence of ACTH pulses after hypophysectomy is a risk factor for the recurrence of hyperadrenocorticism.