A patient with preclinical Cushing's syndrome and excessive DHEA-S secretion having unilateral adrenal carcinoma and contralateral adenoma.

We report a case of preclinical Cushing's syndrome in a 54-year-old male associated with bilateral adrenocortical tumours. Physical findings and general laboratory data were unremarkable except for mild hypertension (158/90 mmHg) and impaired glucose tolerance. Endocrinological evaluation revealed the presence of autonomous cortisol secretion including unsuppressible serum cortisol by 8 mg dexamethasone test (11 microg/dl), high serum DHEA-S (3580 ng/ml, normal: 400-3500) and increased urinary 17-KS excretion (31.0-35.8 mg/day, normal: 5.8-21.3). CT scan demonstrated the presence of tumours in both adrenals and bilateral adrenalectomy was subsequently performed. Histological examination of the resected specimens revealed an adrenocortical carcinoma on the right side and an adenoma on the left side with noticeable cortical atrophy in non-neoplastic adrenals. Immunohistochemical study of steroidogenic enzymes demonstrated that all the steroidogenic enzymes involved in cortisol biosynthesis were expressed in both right and left adrenal tumours. Enzymatic activities of 21, 17alpha, 18, 11beta-hydroxylases were detected in both right and left adrenals except for the absence of 11beta-hydroxylase activity in the left adrenal adenoma. Results of in vitro tissue steroidogenesis examined in short-term tissue culture of the specimens revealed no significant differences between carcinoma and adenoma in cortisol production, but the production of adrenal androgens in carcinoma was significantly higher than that in adenoma, which may indicate the importance of evaluating adrenal androgen levels in patients with adrenocortical neoplasms.     

Cushing's syndrome due to bilateral adrenocortical adenomas with unique histological features

Cushing's syndrome due to bilateral cortisol-secreting adenomas rarely occurs. We present a case of Cushing's syndrome due to bilateral adenomas. Both adenomas had distinct cell compositions, and were compared with emphasis on immunohistochemical and enzyme histochemical analysis for cytochrome P450(11beta) and 3beta-hydroxysteroid dehydrogenase (3betaHSD). A 37 year-old female was diagnosed with ACTH-independent Cushing's syndrome based on physical findings and hormonal evaluation. High-resolution CT scan showed bilateral adrenocortical adenomas and atrophied glands. 131I-methylnorcholesterol incorporation into both glands suggested both adenomas were functional. Clinical diagnosis prior to surgery was ACTH-independent Cushing's syndrome due to functioning bilateral adenomas. The left adrenal gland was totally resected, while the right one was partially resected by laparoscopic approach. Both adenomas were black on cut sections, and were comparatively evaluated by immunohistochemical and enzyme histochemical analysis for P450(11beta) and 3betaSD. The left adenoma was 1.6 cm in diameter and had a complex cellular composition and enzyme expression similar to that of primary pigmented nodular adrenocortical disease (PPNAD), while the right adenoma was 1.8 cm in diameter with compact cells typical of a solitary cortisol-producing adenoma. Adjacent bilateral adrenal cortex showed marked atrophy, but contained several micronodules. Serum cortisol levels, both at basal and after a low dodexamethasone, normalized thirteen months after surgery. In conclusion, the present case of Cushing's syndrome with bilateral adrenal adenomas demonstrated for the first time the simultaneous occurrence of two distinct adenomas, an ordinary cortisol-producing adenoma and a PPNAD-like adenoma. Further case reports of multiple adrenal adenomas should be well-analyzed to clarify whether the results from this case represent a new subgroup of ACTH-independent Cushing's syndrome.     

Abrupt enlargement of adrenal incidentaloma: a case of isolated adrenal metastasis

A 56-year-old Japanese man was referred for examination of right adrenal tumor (3 cm). He had no apparent preexisting cancer by radiological workup and accordingly, the patient was considered as a nonfunctioning adrenocortical adenoma and scheduled for periodic CT scans every 6 months. However, five months after the initial diagnosis the patient complained of severe right back pain with remarkable enlargement of both adrenals (~20-fold volume). Although the origin of adrenal tumor was uncertain by pathological workup, positron emission tomography (PET) scan with (18)F-2-fluoro-D-deoxyglucose (FDG) eventually revealed a hot spot on left upper lung, which was consistent with a lesion of thickened bulla wall observed by chest CT. The present case is a very rare example of abrupt enlargement of bilateral adrenals due to clinically isolated adrenal metastasis, suggesting the requirement of frequent observation with greatest care regarding morphologic changes of adrenal incidentalomas.     

Myelolipomatous foci in an adrenal adenoma causing Cushing's syndrome?

We present a case of Cushing's syndrome in a 60-year old man. Abdominal imaging revealed a right adrenal mass. After confirmation of the diagnosis, the right adrenal gland was resected and revealed a tumor containing a combined myelolipoma and adenoma of the adrenal gland. After surgical removal of the adrenal mass, the symptoms and clinical signs of Cushing's syndrome resolved gradually. Immunohistochemical analysis of the adrenal adenoma specimens showed a high lymphocyte population, particularly within the myelolipoma, and an unusually marked intermingling of myelolipomatous and adrenocortical tumor cells. Adrenocortical clear cells were found in direct contact with T and B lymphocytes. Immune-endocrine mechanisms may have triggered the corticotropin-independent adrenal Cushing's syndrome in this patient.     

Cushing's syndrome associated with bilateral adrenal adenomas

The fifth case of Cushing's syndrome with bilateral adrenocortical tumours is described. By the hormonal dynamic studies both tumours have been shown to be autonomous in the secretion of cortisol. Histopathologically, both tumours were identified as benign adrenocortical adenomas without nodules, and the right one was a so-called black adenoma. A high concentration of cortisol was obtained from both tumour tissue extracts. The differential diagnosis of Cushing's syndrome due to bilateral adrenocortical adenomas from primary adrenocortical nodular dysplasia is briefly discussed.     

Image diagnosis of adrenal disorders--II. Cushing's syndrome

Comparative study of image diagnosis of ultrasonography (US) by linear electronic scanner, computed tomography (CT), and adrenal scintigraphy was performed in 14 patients with Cushing's syndrome. Adrenal imaging by scintigraphy was performed at the 5th and 6th day or further 7th day following the injection of 1 mCi of Adosterol. Cushing's disease (11 cases) US failed to detect the adrenals in 4 cases examined. Measurement of the adrenals on CT film demonstrated the enlargement of adrenals (greater than mean + 2SD) in 6 of 7 cases (85.7%). Scintiscanning showed the increased uptake of bilateral adrenals in 4 of 10 cases (40%). Adrenal scintigraphy with dexamethasone pretreatment (DP) still demonstrated the isotope uptake of bilateral adrenals in all of those 4 cases tested, although the other 6 cases were not studied with DP. From these findings, it was suggested that the measurement of adrenal size by CT was useful for the additional image diagnosis of Cushing's disease, and the adrenal scintigraphy with DP was also available for complementary study of Cushing's disease. Cushing's syndrome due to adrenocortical adenoma (3 cases) In one case examined by US, which had the smallest adenoma (0.6 X 1.0 X 2.0 cm) in this syndrome, the adenoma was not detected. All of 3 adrenal adenomas (2.6 X 2.6 X 2.2 cm to 0.6 X 1.0 X 2.0 cm) were detected by CT. Adrenal scintigraphy demonstrated good uptake by adrenal adenoma but no visualization of the contralateral adrenal in every case.     

Adrenal tuberculosis in Cushing's disease with bilateral macronodular adrenocortical hyperplasia

Cushing's disease is a disorder of hypercortisolism caused by a pituitary micro- or macro-adenoma. Most patients with Cushing's disease have a bilateral adrenal enlargement, which depends on the duration of the disease, as a result of the long standing ACTH stimulation of both adrenal glands. However, in macronodular adrenocortical hyperplasia (MNH) that is caused by Cushing's disease, if the MNH gains autonomy, a bilateral adrenalectomy, as well as the removal of pituitary adenoma, is often essential. We encountered a patient diagnosed with Cushing's disease with bilateral adrenal tuberculosis simulating MNH. She had taken anti-tuberculosis medications one year prior to admission due to spinal tuberculosis. Sellar MRI revealed a pituitary macroadenoma, but adrenal CT showed enlargement in both adrenal glands that appeared to be MNH. A hormonal study and bilateral inferior petrosal sinus sampling revealed Cushing's disease. Therefore, she underwent trans-sphenoidal surgery of the pituitary mass. The pituitary surgery was successful and the serum cortisol returned to normal range. However, the adrenal mass rapidly enlarged after removing the pituitary tumor without showing evidence of a recurrence or adrenal autonomy of hypercortisolism. Accordingly, a laparoscopic left adrenalectomy was performed to examine the nature of the mass. The resected left adrenal gland was pathologically determined to have a lesion of tuberculosis with some part of the intact cortex. So we assumed that the cause of rapid adrenal enlargement might be due to adrenal tuberculosis. In summary, to the best of our knowledge, this is the first case of Cushing's disease coexisting with both adrenal tuberculosis simulating a bilateral MNH.     

A case of preclinical Cushing's syndrome associated with diurnal rhythms of ACTH and cortisol in blood: correlation with histological findings

We describe a case of adrenocortical adenoma with preclinical Cushing's syndrome demonstrating diurnal rhythms of ACTH and cortisol in blood. A 50-year-old man was admitted to the hospital for the evaluation of incidental right adrenal mass with hyperglycemia and hypertension. On admission, there were no signs of clinical manifestation of hypercortisolism. The basal levels of cortisol (9.3 microg/dl) and ACTH (9.4 pg/ml) at 0800 h were not elevated and these diurnal rhythms were maintained. One or 8 mg of dexamethasone given orally overnight suppressed the plasma ACTH but not serum cortisol. Ultrasonogram, CT and scintiscan of (131)I adosterol all demonstrated an enlarged adrenal mass in the right adrenal gland. The right adrenal gland was subsequently resected by laparoscopic surgery. Histopathological findings of resected adrenal tumor were consistent with adrenocortical adenoma. Adjacent non-neoplastic adrenal tissue demonstrated adrenocortical atrophy but DHEA-sulfotransferase immunoreactivity in the zona reticularis was detected.     

Unilateral adrenalectomy improves insulin resistance and polycystic ovaries in a middle-aged woman with virilizing adrenocortical adenoma complicated with Cushing's syndrome

A benign virilizing adrenal adenoma is rare among adrenal neoplasms in middle-aged women. A 39-yr-old Japanese woman who presented with hirsutism, obesity, diabetes mellitus and hypertension was admitted. Plasma concentrations of testosterone and DHEAS were high. While the basal level of plasma ACTH was suppressed, serum cortisol level was high and its circadian rhythm was absent. Serum cortisol level was not suppressed with the low- and high-dose overnight dexamethasone suppression test. Abdominal computed tomography showed a left adrenal tumor, and an adrenocortical scintigraphy revealed uptake of the tracer on the left side. Polycystic ovaries were also found and bone mineral density revealed osteoporosis. Histopathological features of resected adrenal tumor were consistent with those of adrenocortical adenoma. Immunoreactivity of all the steroidogenic enzymes was apparent in the tumor cells and particularly dehydroepiandrosterone sulfotransferase (DHEA-ST) immunoreactivity was markedly expressed. Cortical atrophy and reduced expression of DHEA-ST were detected in the cortex of the adjacent non-neoplastic adrenal gland. Plasma testosterone, DHEAS and cortisol levels returned to normal after surgery, concomitantly with the disappearance of polycystic ovaries. This is a very rare case of virilizing adrenocortical adenoma complicated with Cushing's syndrome (CS).     

Cushing's syndrome presenting the coexistence of a pituitary corticotrophic cell hyperplasia and a unilateral functional adrenal adenoma

A very unusual case of Cushing's syndrome is presented. Most of the preoperative biochemical and radiological examinations were compatible with Cushing's syndrome owing to a right adrenal adenoma. Exceptional findings include normal concentrations of adrenocorticotrophin (ACTH) in plasma as well as a disturbance of its circadian rhythmicity and a significant adrenocortical responsiveness to exogenous ACTH. Secretory patterns of ACTH did not change even after right adrenalectomy. Studies in vitro revealed that the adenoma itself, but not the surrounding normal adrenal, was the source of cortisol secreted in response to ACTH. Post mortem examinations disclosed unexpectedly a hormonally inactive left adrenal adenoma and a focal hyperplastic lesion of the anterior pituitary with an ACTH concentration 53 times higher than that of the remaining tissue of the gland. It is a possibility that this case may have represented a transition between pituitary-dependent adrenocortical hyperplasia and adrenal adenoma to this date reported in only one similar case.     

Different sensitivity to adrenocorticotropin of dispersed adrenocortical cells from patients with Cushing's disease with macronodular and diffuse adrenal hyperplasia

A patient with Cushing's syndrome and low plasma ACTH levels had a unilateral adrenal mass (diameter, 3 cm), which proved to consist of adenomatous hyperplasia. Dispersed adrenocortical cells prepared from this mass responded to ACTH with a maximal increment in cortisol release of more than 400%. Five months after operation Cushing's syndrome recurred. Computed tomography scanning showed an enlarged macronodular adrenal gland on the other side. The cells prepared from this adrenal gland were stimulated by ACTH by more than 600%. In adrenal glands from eight other patients with Cushing's disease cells from macroscopic nodules in hyperplastic adrenocortical tissue had increased responsiveness to ACTH in vitro, in comparison to cells from macroscopically diffuse hyperplastic adrenal tissue. The stimulability of the pituitary-adrenal axis (by metyrapone) and its suppressibility (by high dose dexamethasone) did not differ between the two groups of patients. These observations suggest that in the presence of adenomatous or macronodular adrenal hyperplasia lower circulating ACTH levels may sustain hypercortisolism than in diffuse adrenal hyperplasia. The presence of a unilateral adrenal mass and low normal plasma ACTH levels in patients with Cushing's syndrome, therefore, does not unequivocally indicate the presence of an autonomous adrenal adenoma. Tests with metyrapone and dexamethasone should still be carried out in order to make a secure differential diagnosis.     

Coexistence of pituitary adrenocorticotropin-dependent Cushing's syndrome with a solitary adrenal adenoma

A 45-yr-old woman presented with a 2-hr history of Cushing's syndrome. Baseline cortisol and ACTH levels were elevated and lacked a normal circadian rhythm. Dynamic testing of her pituitary-adrenal function revealed positive responses to metyrapone and synthetic ACTH and suppression with high doses of dexamethasone. The finding of asymmetrical adrenal uptake of 6-[131I]methyl-19-nor-cholesterol and a tumor image in the right adrenal on venography led to the preoperative diagnosis of pituitary ACTH-dependent adrenal hyperfunction coexisting with a right adrenal adenoma. Surgical resection of the right adrenal demonstrated a solitary 39-g nodule, 4 cm in diameter. There were no additional nodules present in the surrounding cortex. When incubated in vitro, both the adenoma and the surrounding tissue were functional and responsive to ACTH. This was in contrast to the lack of response to ACTH in vitro of similar tissues removed from two other patients with ACTH-independent adrenal adenomas. We suggest that this case represents a transition between pituitary ACTH-dependent bilateral adrenocortical hyperfunction and solitary adrenal adenoma.     

ACTH independent Cushing's syndrome occurring in siblings

Familial Cushing's syndrome due to ACTH independent bilateral macronodular adrenocortical hyperplasia occurring in siblings is reported. The proband was a 69-year-old woman who presented with a typical Cushingoid appearance. The serum cortisol level was elevated, with a loss of diurnal rhythm, and the plasma ACTH level was undetectable. Dynamic testing showed no suppression of urinary 17-OHCS by high dose dexamethasone and no stimulation by metyrapone. An abdominal CT scan showed bilateral adrenal enlargement. The patient died of a subarachnoid haemorrhage, and autopsy revealed a massively thickened adrenal cortex composed of nodules up to 3.5 cm in diameter. A pituitary adenoma was not found. We learned that the patient's elder brother was also diagnosed at 59 years of age with Cushing's syndrome due to bilateral macronodular adrenocortical hyperplasia. His plasma cortisol levels were not suppressed by high dose dexamethasone and the plasma ACTH level was undetectable. Screening of the available family members by administering 1 mg dexamethasone at midnight and performing abdominal CT scan revealed impaired suppressibility of serum cortisol associated with enlarged bilateral adrenal glands in a 64-year-old sister and a 54-year-old brother. The 64-year-old sister was considered as a possible 'affected' case in the early stages of development, because the basal level of ACTH was not suppressed and hyperplasia of the bilateral adrenal glands as revealed by CT scan was less evident.     

Concurrent adrenocortical carcinoma and Conn's adenoma in a man with primary hyperaldosteronism. In vivo and in vitro studies.

This is a report of a rare and unusual case of adrenal pathology. A patient presented with clinical and biological signs of primary aldosteronism and computed body tomography scan led to our suspecting the presence of a left adrenocortical carcinoma. The in vitro studies performed on the resected tumour showed very low synthesis of mineralocorticoids and glucocorticoids. The patient could not be reexamined until 15 months later, when he still suffered hypertension; another tomography scan revealed a mass on the right adrenal gland. The studies performed on this second tumour confirmed the diagnosis of Conn's adenoma: active in vitro biosynthesis of 18-hydroxy-corticosterone and aldosterone from exogenous tritiated precursors.     

FAMILIAL CUSHING'S SYNDROME DUE TO NODULAR ADRENOCORTICAL DYSPLASIA. A PUTATIVE RECEPTOR-ANTIBODY DISEASE?

Two sisters aged 13 and 19 years suffering from familial Cushing's syndrome due to nodular adrenocortical dysplasia are described. Pituitary adrenocortical function tests indicated the presence of adrenal autonomy. Adrenal scintigraphy showed bilateral symmetrical uptake indicating the bilateral character of the autonomous process. Complete adrenalectomy was performed in both girls. The adrenals were of about normal weight showing numerous dark brown pigmented nodules and small perivascular lymphocytic infiltrates. Serum immunoglobulin preparations obtained from both girls stimulated adrenocortical cell growth in a cytochemical bioassay system. It is proposed that circulating growth factors may be involved in the pathogenesis of the disease.     

A case of aldosterone-producing adrenocortical adenoma associated with preclinical Cushing's syndrome and hypersecretion of parathyroid hormone

A rare case of aldosterone-producing adrenocortical adenoma with preclinical Cushing's syndrome and hypersecretion of parathyroid hormone (PTH) is described. A 64-year-old male patient had a history of hypertension for two decades and hypokalemia for 4 years. He suffered from left hemiparesis and aphasia due to cerebral hemorrhage, but his appearance was not Cushingoid. His plasma renin activity was below the normal range, while plasma aldosterone concentration was high. They did not respond to furosemide-upright test. His plasma cortisol level in the morning was at the upper limit of the normal range, but it did not show a diurnal rhythm nor was it suppressed by 1 mg and 8 mg of dexamethasone. Computed tomography showed a low density tumor in the right adrenal gland. An adrenal scintigram under dexamethasone treatment revealed an uptake of the tracer on the right side, and plasma aldosterone and cortisol concentrations in the adrenal vein were higher on the right side than on the opposite. The diagnosis of right aldosterone-producing adrenal adenoma with an autonomous production of cortisol was confirmed by right adrenalectomy. Histological findings showed an adenoma consisting mostly of clear cells, but that the nests of compact cells were scattered. Analysis of an extract from the adenoma revealed that the adenoma contained an excess amount of aldosterone and that the cortisol/corticosterone ratio was higher than that of aldosterone-producing adenoma. Both serum calcium and PTH levels remained high one year after adrenalectomy. Ultrasonography revealed the swelling of a parathyroid gland on the left side, indicating the coexistence of an autonomous hyperparathyroidism.     

GIP-dependent adrenal Cushing's syndrome with incomplete suppression of ACTH

ACTH-independent Cushing's syndrome may be due to the development of ectopic hormone receptors in adrenal tissue. Thus, in food-dependent Cushing's syndrome the adrenals aberrantly express receptors for gastric inhibitory polypeptide (GIP). We present the case of a 60-year-old woman with food-dependent Cushing's syndrome whose cortisol levels increased after stimulation with CRH. In this patient with Cushing's syndrome the finding of low basal plasma cortisol levels in the late night and early morning as well as a paradoxical rise of plasma cortisol during a 7-h infusion with dexamethasone (carried out without any restriction in food intake), suggested that cortisol production was stimulated at times of food intake. Hourly measurements of plasma cortisol for 48 h revealed prominent meal-related peaks. A plasma cortisol response, elicited by oral glucose administration, could be prevented by octreotide. Plasma ACTH was low or undetectable. CRH administration was followed by a ACTH response from 3 to 16 ng/l and a plasma cortisol response from 230 to 680 nmol/l. Octreotide treatment for nearly five months induced a partial clinical and biochemical remission. Total bilateral adrenalectomy was performed. The left adrenal was grossly enlarged (7 x 5.5 x 4 cm) and the right adrenal was slightly enlarged (6 x 4 x 1.8 cm). Microscopy revealed bilateral nodular hyperplasia. Cell suspensions of adrenal tissue from the patient did respond in a dose-dependent fashion to stimulation with GIP and were very sensitive to stimulation with synthetic ACTH1-24. However, CRH had no significant effect on cortisol production in vitro. Using RT-PCR amplification and cDNA hybridization, GIP receptor was found to be overexpressed in the left and right adrenal tissues from this patient as compared to adrenal tissues from a normal individual or from non GIP-dependent adrenal Cushing's syndrome. There was no evidence of presence of adrenal CRH receptors. Thus, in this patient with food-dependent Cushing's syndrome, the CRH-induced plasma ACTH and cortisol response is probably mediated by an incomplete suppression of the HPA axis as a result of the intermittent food-dependent nature of Cushing's syndrome.     

Cardiomyopathy associated with Graves'' disease

A case of an adrenal incidentaloma in a 57-year-old man with silent 21-hydroxylase deficiency is reported. Abdominal computed tomography revealed a right adrenal tumour of 6cm in diameter. There was no evidence of adrenal hormone excess. However, after surgical removal of the adrenal tumour, the patient developed acute adrenal insufficiency. Adrenocortical function has remained low ever since surgery. Pathological examination of the tumour revealed a cortical adenoma. On the basis of increased plasma renin activity and serum 17α-hydroxyprogesterone concentration and decreased 21-hydroxylase activity of the adenoma tissue, the patient was diagnosed as having systemic 21-hydroxylase deficiency. There are two possible mechanisms for the persistent adrenal insufficiency; first the residual left adrenal gland may have been originally hypo-functioning for some reason and, second, the left gland may have lost the ability to regenerate following prolonged suppression by the adenoma. In cases of adrenal incidentalomas with 21-hydroxylase deficiency, the indications for surgical removal should be carefully considered.     

Cushing's syndrome patient who exhibited congestive heart failure

Cushing's Syndrome (CS) may sometimes lead to dilated cardiomyopathy, even though this condition can be partially or completely reversed after treatment. In this article we report the case of a 28-yr-old woman with CS secondary to adrenal adenoma who exhibited congestive heart failure as an initial symptom. Two weeks before being admitted to our hospital, the patient started complaining of shortness of breath, orthopnea, paroxysmal nocturnal dyspnea and generalized edema. A physical examination did not reveal signs of hypercortisolism. Chest auscultation revealed bilateral diffused crepitation; blood pressure was 180/120 mmHg with heart rate of 90 beats/min. A chest X-ray showed a cardiac shade enlargement due to congestive heart failure. Transthoracic echocardiography demonstrated a dilated left ventricle and an impaired left ventricular systolic function. The patient's urinary cortisol excretion was elevated and circadian rhythm of cortisol was absent. ACTH level was low. In addition, plasma cortisol failed to decrease after administration of dexamethasone. An abdominal magnetic resonance imaging scan showed a 7-cm right adrenal mass. The patient was administered oxygen, spironolactone, ACE-inhibitor and the signs and symptoms of heart failure gradually improved. A laparoscopic right adrenalectomy was performed and pathological examination of the gland showed a benign adrenocortical adenoma. After the adrenalectomy the patient was started on hydrocortisone therapy and 5 months later the wall thickness of the left ventricle was within normal range and the patient's blood pressure was 130/80 mmHg. In conclusion we report the case of heart failure as the main clinical symptom in CS secondary to adrenal adenoma.     

Bilateral adrenocortical adenomas causing ACTH-independent Cushing's syndrome at different periods: a case report and discussion of corticosteroid replacement therapy following bilateral adrenalectomy

We report a rare case of bilateral adrenocortical adenomas causing ACTH-independent Cushing's syndrome at different periods 9 yr apart. The subject, a 24-yr-old woman, in June 1989 had a typical Cushingoid appearance. Her baseline plasma cortisol levels did not show a diurnal rhythm and she had a very low baseline plasma ACTH level. Plasma cortisol levels could not be suppressed by overnight low-dose or two-day high-dose dexamethasone suppression test. Marked uptake of 131I-6beta-iodomethyl-19-norcholesterol (NP-59) was observed in the right adrenal gland. Abdominal computed tomography (CT) showed a right adrenal tumor. The right adrenal gland with adenoma was removed. The non-tumorous part of the adrenal cortex was atrophic. By April 1998, she had experienced a weight gain of more than 20 kg over a two-yr period. The baseline plasma cortisol levels were at the lower limit of the normal range with loss of diurnal rhythmicity. The baseline plasma ACTH levels were very low. Neither a two-day low-dose nor a two-day high-dose dexamethasone suppression test could suppress serum cortisol or urinary free cortisol levels. NP-59 adrenal scan revealed increased uptake of the left adrenal gland at 72 h after intravenous injection of the tracer. Abdominal CT and magnetic resonance imaging (MRI) all demonstrated a left adrenal mass. Left adrenalectomy was performed in June 1998; histological features showed a cortical adenoma and atrophic change in the non-tumorous part of the adrenal cortex. Elevated plasma ACTH levels after bilateral adrenalectomy could be suppressed with conventional corticosteroid replacement therapy and overnight low-dose dexamethasone suppression test.