Feline abdominal ultrasonography: what's normal? what's abnormal? The adrenal glands.

PRACTICAL RELEVANCE: Abdominal ultrasound plays a vital role in the diagnostic work-up of many cats presenting to general and specialist practitioners. Ultrasound examination of the adrenal glands can provide important information pertaining to several conditions including hyperaldosteronism and hyperadrenocorticism. CLINICAL CHALLENGES: Despite ultrasonography being a commonly used modality, many practitioners are not comfortable performing an ultrasound examination or interpreting the resulting images. Even for the experienced ultrasonographer, differentiating between incidental findings, such as adrenal mineralisation, and clinically significant pathological changes can be challenging. AIM: This review, part of an occasional series on feline abdominal ultrasonography, discusses the ultrasonographic examination of the normal and diseased adrenal glands. Aimed at general practitioners who wish to improve their knowledge of and confidence in feline abdominal ultrasound, this review is accompanied by high-resolution images and videos available online as supplementary material. EQUIPMENT: Ultrasound facilities are readily available to most practitioners, although the use of ultrasonography as a diagnostic tool is highly dependent on operator experience. EVIDENCE BASE: Information provided in this article is drawn from the published literature and the author's own clinical experience.

Successful percutaneous CT-guided microwave ablation of adrenal gland for ectopic Cushing syndrome.

Adrenocorticotropic hormone production by pancreatic neuroendocrine tumor (PNET) is rare and results in hyperstimulation of the adrenal gland to produce ectopic Cushing syndrome. Our case showcases the safety and effectiveness of percutaneous CT-guided microwave ablation of the adrenal gland in a 49-year-old female with PNET and hepatic metastases who presented with ectopic Cushing syndrome despite surgical resection of the primary pancreatic tumor and left adrenal gland. Prior to ablation, the right adrenal gland measured 4.3×1.6×2.0cm and the patient had malignant hypertension with elevated morning serum cortisol level (1976nmol/L). After microwave ablation of the right adrenal gland, the hypertension resolved and the cortisol level decreased dramatically (74nmol/L). As expected after successful treatment, the patient developed adrenal insufficiency and was placed on glucocorticoid and mineralocorticoid supplementation.

Hypokalaemia in a hyperthyroid domestic shorthair cat with adrenal hyperplasia.

A 13-year-old female domestic shorthair cat presented with polyphagia and weight loss. Marked systolic hypertension was found on examination. Elevated total thyroxine levels confirmed hyperthyroidism, and hypokalaemia was also documented. A euthyroid state and normotension were achieved following 4 weeks of treatment with carbimazole and amlodipine. Despite potassium supplementation, the hypokalaemia worsened. Abdominal ultrasonography revealed left adrenomegaly. Plasma aldosterone concentrations were initially in the lower half of the reference interval and, when repeated 2 months later, were undetectable. Urea and creatinine remained in the lower half of the reference interval throughout treatment, and urine specific gravity suggested good urine concentrating ability. The fractional excretion of potassium confirmed a renal source of potassium loss. Blood gas analysis was unremarkable. It was theorised that an aldosterone precursor was causing signs of mineralocorticoid excess and undetectable plasma aldosterone levels. Treatment with an aldosterone receptor antagonist successfully increased the serum potassium concentration. Owing to difficulties administering medication and associated effects on life quality the cat was euthanased. Adrenal hyperplasia was apparent on post-mortem histopathology.

A novel mutation in the MC2R gene causing familial glucocorticoid deficiency type 1.

Familial glucocorticoid deficiency (FGD) or hereditary unresponsiveness to adrenocorticotropin (ACTH) is an autosomal recessive disorder characterized by isolated glucocorticoid deficiency associated with normal mineralocorticoid secretion. Mutations in genes encoding either ACTH receptor or melanocortin 2 receptor accessory protein are responsible for the disease in about 50% of cases, named FGD type 1 and type 2, respectively. Patients may present with hyperpigmentation, recurrent infections, failure to thrive, hypoglycemic seizures, and coma in infancy or early childhood. Here we report the case of a 17-day-old newborn diagnosed with FGD type 1 who presented with hyperbilirubinemia and hyperpigmentation, a sign which was erroneously assumed to be due to prolonged phototherapy by the referring physician. Hormone analysis showed low cortisol and high ACTH levels with normal serum electrolytes and renin-aldosterone axis. Genetic analysis revealed a novel homozygous melanocortin 2 receptor mutation p.Leu225Arg in the patient. The healthy parents were heterozygous for the mutation.

Investigation of the hypothalamo-pituitary-adrenal axis and changes in the size of adrenal glands in acute brucellosis.

The aim of the study was to investigate the hypothalamo-pituitary-adrenal (HPA) axis by ACTH stimulation test and the changes in adrenal size in acute brucellosis before and after therapy in a prospective study. Sixteen patients with acute brucellosis and 15 healthy subjects were included in the study during the last two years. Cortisol levels were assessed before, 30 and 60 minutes after ACTH (250 microg i.v.) injection and the size of the adrenals was measured in both groups. Mean basal cortisol levels in the patients before the therapy and after the therapy were 22.1 +/- 6.9 microg/dL and 11.3 +/- 6.0 microg/dL, respectively. The difference was statistically significant (p<0.001). There was also statistically significant difference for basal cortisol levels between the healthy subjects (12.2 +/- 4.6 microg/dL) and the patients before the therapy (p<0.001). Peak cortisol responses to ACTH were higher before the therapy in the patients with acute brucellosis (39.3 +/- 10.7 microg/dL) than in the healthy subjects (30.4 +/- 4.8 microg/dL, p = 0.014). However, there was no significant difference for peak cortisol levels in the patients before and after the therapy (32.7 +/- 8.0 microg/dL). Mean basal cortisol levels and peak cortisol responses to ACTH between the patients after the therapy and the healthy controls were similar. Both the maximum width of the adrenal glands and the width of the adrenal limbs were significantly greater before the therapy compared to healthy subjects and post-treatment period. We concluded that the HPA axis is activated and the adrenal glands are enlarged in acute brucellosis, which is reduced after appropriate therapy.

Hyperaldosteronism in a cat with metastasised adrenocortical tumour.

In a 12-year-old male shorthaired cat with attacks of hypokalaemic muscular weakness in spite of oral potassium supplementation, highly elevated plasma aldosterone concentrations in combination with low plasma renin activity pointed to primary hyperaldosteronism. Ultrasonography and computed tomography revealed a large left-sided adrenal tumour growing into the phrenicoabdominal vein and the caudal vena cava. The tumour and its intravascular extension were surgically removed, but the subsequent stenosis of the caudal vena cava caused congestion and renal failure. At autopsy pulmonary micrometastases of the aldosteronoma were found.

Establishment of assisted reproduction technologies in female and male African wild dogs (Lycaon pictus).

Transrectal ultrasonography, electroejaculation and cryopreservation of spermatozoa were applied to the African wild dog (Lycaon pictus) to establish non-invasive protocols for assessing the reproductive health of one of the most endangered African canids. Transrectal ultrasonography was performed on immobilized male (n = 2) and female (n = 5) captive wild dogs. The testes and epididymides of the male dogs were imaged transcutaneously, followed by electrostimulation and cryopreservation of spermatozoa. The sonomorphology of the female and male urogenital tracts was characterized. In females, the vagina, cervix, non-pregnant uterus and ovary were imaged and the reproductive health of each female was evaluated. The sonographic assessment helped to identify one pyometra and extensive abdominal fat deposits in two other individuals in which pyometra had been suspected. Images of the adrenal glands showed differences in size among individuals of the same breeding group. Whether these differences were related to the dominance hierarchy remains to be determined. In males, visualization of the prostate gland, testis and epididymis indicated sexual maturity. Three ejaculatory fractions (1.0, 1.5 and 0.5 ml, with 50, 95 and 95% motility, respectively; 1.125 x 10(8) spermatozoa per ejaculate) were collected from one male. The motility of each of these fractions after thawing was 0, 30 and 40%, respectively. Electrostimulation of the second male, in which a cystic structure in a testis had been identified by sonography, resulted in an aspermic ejaculate (0.5 and 1.0 ml). These technologies provided basic data on reproduction in female and male African wild dogs and were an efficient way to evaluate reproductive health.

Use of abdominal ultrasonography in the diagnosis of primary hyperaldosteronism in a cat.

A 13-year-old castrated male cat was examined because of a 2-week history of weakness, cervical ventroflexion, and dysphagia. Clinicopathologic abnormalities included hypokalemia and high serum creatine kinase activity. Abdominal ultrasonography revealed a 15-mm spherical mass in the area of the left adrenal gland. Plasma aldosterone concentration was high, and plasma renin activity was low. Findings were diagnostic of primary hyperaldosteronism. The cat responded well to intravenous and oral potassium supplementation while in the hospital. The owner declined surgery; therefore, repeated follow-up abdominal ultrasonography was recommended. The cat did well clinically with medical management alone until day 334, when it was lost to follow-up.

Primary hyperaldosteronism in pregnancy. A case report.

BACKGROUND: Primary hyperaldosteronism is an uncommon disorder, and there are few reports of its occurrence and management in pregnancy. CASE: Primary hyperaldosteronism was suspected before pregnancy in a 31-year-old women with refractory hypertension and hypokalemia. Pregnancy evaluation revealed suppressed renin levels and high aldosterone levels; computed tomography revealed a 1-cm mass in the left adrenal gland. The patient became pregnant before completion of evaluation and treatment. On high doses of nifedipine and nadolol, the first-trimester blood pressure was 130/98 mm Hg and remained high in the early second trimester. In view of the risks of poorly controlled hypertension, adrenalectomy was performed at 15 weeks' gestation, with rapid improvement in blood pressure and elimination of the patient's requirement for large doses of potassium daily. Antihypertensive medication was withdrawn, with maintenance of normal blood pressure until 36 weeks' gestation. At that time the blood pressure rose slightly but responded to bed rest. A healthy female infant was delivered at term by cesarean section. CONCLUSION: Previous reports of emergency preterm delivery and a case of neonatal mortality in the setting of hyperaldosteronism in pregnancy confirm the significant risks associated with this condition. In our patient, adrenalectomy in the early second trimester resulted in a rapid and sustained improvement in hypertension, reversal of hypokalemia and a good pregnancy outcome.

Hypothalamo-pituitary-adrenal function in human immunodeficiency virus-infected men.

We prospectively studied adrenal function in 51 human immunodeficiency virus-positive male patients, including heterosexuals, homosexuals, and iv drug users, classified according to 1987 CDC criteria as belonging to stages II/III or IVC. Basal serum concentrations of cortisol (F), progesterone (P4) and 17 alpha-hydroxyprogesterone (17 alpha-OHP4) were determined during the two stages. In stage IVC patients, the circadian rhythms of ACTH and F were assessed, and ovine CRH (oCRH) and immediate cosyntropin-stimulating tests were evaluated. Serum concentrations of hormones were analyzed in relationship to the absolute CD4 cell count in all subjects. The mean serum F concentration in stage IVC patients, the mean P4 concentration in stage II/III and IVC patients, and the mean 17 alpha-OHP4 level in stage II/III patients were significantly increased compared to control values (P < 0.0001, P < 0.0001, and P < 0.002, respectively). The mean serum F concentration in stage IVC patients was significantly increased compared to that in stage II/III patients (P < 0.004), and the mean serum 17 alpha-OHP4 concentration in stage II/III patients was significantly increased compared to that in stage IVC patients (P < 0.02). In the 22 stage IVC patients, the circadian rhythms of ACTH and F were normal in all but 7 for ACTH and 5 for F, whereas oCRH test results indicated that 14 of them had reduced or blunted responses. By contrast, cosyntropin stimulation results were normal. CD4 cell counts were significantly negatively correlated with the serum F concentration (P < 0.02). In conclusion, during human immunodeficiency virus infection, the serum F concentration was negatively correlated with CD4 cell counts. Cosyntropin test results were normal, but 63% of the stage IVC men had abnormal responses to oCRH.

[The role of adrenal gland x-ray computed tomography and scintigraphy using radiolabelled norcholesterol in the etiological diagnosis of primary hyperaldosteronism]. / Place respective de la tomodensitométrie surrénalienne et de la scintigraphie au norcholestérol radiomarqué dans le diagnostic étiologique des hyperaldostéronismes primaires.

The major etiologies of primary aldosteronism are aldosterone-producing adrenal adenoma, requiring a surgical treatment, and bilateral hyperplasia, usually managed with medical therapy. We only report a retrospective study on 22 patients with primary aldosteronism diagnosed by clinical and usual biochemical tests. All the patients were explored by computed tomography scan (CT) and iodomethyl-norcholesterol scintigraphy. The purpose of this study was to compare the capacity of the two methods to differentiate adrenal adenoma and hyperplasia. The CT scan was more sensitive (sensitivity: 88%) compare to scintigraphy (sensitivity: 64%) for the diagnosis of adrenal adenoma. However, the scintigraphy was a useful tool to detect asymmetric macronodular adrenal hyperplasia. Therefore, the catheterisation of adrenal venous would be only necessary for a few cases. We conclude from this study and the literature review that CT scan and iodomethyl-norcholesterol scintigraphy are complementary and both useful to increase diagnostic reliability of primary aldosteronism.

[Forty-one cases of Cushing's syndrome: a comparison between Cushing's syndrome (adrenal adenoma) and Cushing's disease (adrenal hyperplasia)].

We experienced 41 cases of Cushing's syndrome (12 males and 29 females, 15 years old - 65 years old) during the last 20 years. These included 20 patients with unilateral adrenal adenoma (Cushing's syndrome), 19 patients with bilateral adrenal hyperplasia (Cushing's disease), one patient with adrenal carcinoma and one patient with primary adrenocortical nodular dysplasia (PAND). Moreover, these cases included some special ones, i.e. 5 cases with destructive thyroiditis after treatment, 2 cases with aggravation of arthritis after treatment, a case of Carney's complex with PAND, one case with paradoxical response to dexamethasone, and one case combined with empty sella syndrome. The most specific clinical signs were moon face (95% occurrence), hypertension (95%) and subcutaneous bruising (80%). Other significant signs were eye edema (66%), buffalo hump (68%), subcutaneous purpura (63%) and osteoporosis (49%). Skin striae was not a common sign in our cases (41%). Renal stone was observed in only 20% of our patients but was a significant sign in this syndrome. There was no difference in the occurrence of each clinical sign between Cushing's syndrome and Cushing's disease. The elevation of white blood cell count (WBC) and serum sodium, a decrease of serum potassium, and a decrease of reabsorption of phosphate (%TRP) were observed. Thyroid-stimulating hormone (TSH) and human growth hormone (HGH) were suppressed in patients with Cushing's syndrome and patients with Cushing's disease. These results were consistent with those of previous reports. However, luteinizing hormone (LH), follicle-stimulating hormone (FSH) and prolactin (PRL) were high in those patients with Cushing's syndrome and those with Cushing's disease. Oral glucose tolerance test was carried out in 34 patients before and after treatment. Thirty-one percent of those had diabetes mellitus and 26% had impaired glucose tolerance (IGT). The response of IRI in this test was high in patients with Cushing's syndrome and patients with Cushing's disease, and decreased 4 weeks after treatment in those with Cushing's syndrome but remained high in those with Cushing's disease. Plasma ACTH level and urinary 17-OHCS excretion were significantly higher in Cushing's disease than in Cushing's syndrome. During an 8mg-high-dose dexamethasone suppression test, urinary 17-OHCS excretion in 13 of 14 patients with Cushing's disease (93%) was suppressed by more than 50% of baseline on the second day of testing. However, all of 18 patients with Cushing's syndrome, who had an 8mg-dexamethasone suppression test, failed to suppress urinary 17-OHCS by 50% of baseline.(ABSTRACT TRUNCATED AT 400 WORDS)

[131I-meta-iodobenzylguanidine scintigraphy in patients with a suspected pheochromocytoma. A comparison with CT and biohumoral parameters]. / La scintigrafia con 131I metaiodobenzilguanidina in pazienti con sospetto feocromocitoma. Confronto con TC e parametri bioumorali.

The results of 131I metaiodobenzylguanidine (MIBG) and Computed Tomography (CT) scans in a group of patients with clinically suspected pheochromocytoma were evaluated and compared with biohumoral parameters. We studied 24 consecutive patients (7 M and 17 F; age range 20-66 years). 131I-MIBG scintigraphy and CT were in agreement in 19 patients (79%): of them 7 cases were true positive, and 12 were true negative. Disagreement between the two imaging techniques was observed in 5 patients (21%). In this group, one patient, with positive CT scan, had false negative MIBG study, while 4 patients with negative MIBG scan, had false positive CT. MIBG showed significantly higher (p less than 0.05) specificity (100%), positive predictive value (100%), and accuracy (96%) than CT (75%, 67%, and 83%, respectively). 131I-MIBG scintigraphy is an accurate, noninvasive technique for localizing pheochromocytoma and providing direct tissue characterization, while CT provides more accurate spatial information. In conclusion, CT and MIBG studies are complementary in the evaluation of patients with suspected pheochromocytoma.

[A case report of Cushing syndrome due to three distinct adenomas of the right adrenal].

A case is presented of a 40 y.o. female with Cushing's syndrome. Her plasma glucocorticoid values were elevated (11-deoxy-cortisol: 3.46 ng/ml, cortisol: 25.6 micrograms/dl and cortisone: 35.7 ng/ml) with loss of diurnal variation. Urine 17-OHCS value failed to b suppressed by high dose dexamethasone and was unchanged after metyrapone administration. Her plasma mineral corticoids and androgens were within normal limits. There were 3 separate tumors in the right adrenal on CT and the left adrenal had no uptake on 131I-adosterol scintigram. We, therefore, diagnosed her illness as Cushing's syndrome due to unilateral multiple adenomas. Gross and histological examination of the right adrenal revealed one compact cell dominant adenoma and two clear cell dominant adenomas. This is the 4th case of Cushing syndrome due to unilateral multiple adrenal adenomas in Japan.

[A comparison of scintigraphy with radioiodinated MIBG and CT in localizing pheochromocytomas]. / Confronto tra scintigrafia con MIBG radioiodata e TC nella localizzazione dei feocromocitomi.

In order to define the diagnostic roles of MIBG imaging and CT in the detection of pheochromocytomas (pheos), the results obtained in 45 patients suspected of bearing pheo and studied with both modalities were analyzed and compared. Scintigraphy was correctly negative in 22/23 cases, correctly positive in 11/12 adrenal and 5/5 extra-adrenal pheos, and in 4/5 malignant pheos (metastases present in 2 cases were also identified). CT was correctly negative in 20/23 cases (a mass other than a pheo was detected in 3 patients); correctly positive in 12/12 adrenal and 4/5 extra-adrenal pheos and in 5/5 malignant pheos. Sensitivity, specificity and accuracy of scintigraphy and CT were 91% and 95.4%, 95.6% and 87%, 93.3% and 91.1% respectively (differences were not statistically significant). The overall data emphasize the complementary role of 123/131I-MIBG imaging and CT in the location of pheochromocytomas. A flow-chart essentially grounded on the combined use of both these diagnostic modalities is proposed which includes 123/131I-MIBG scintigraphy as a first choice examination.

131I-MIBG--a new agent in diagnosis and treatment of pheochromocytoma.

The newly developed radiopharmaceutical, 131I-metaiodobenzylguanidine (131I-MIBG), has been shown to be efficacious for the location of intra- and extra-adrenal, primary pheochromocytomas and metastatic, malignant pheochromocytomas (11.4% false-negative and 1.8% false-positive in patients with proven pheochromocytomas). Preliminary experience in selected patients with malignant pheochromocytoma suggest that therapy using large doses of 131I-MIBG results in partial tumor regression and improvement in catecholamine hypersecretion in some cases.

Selenium-75-cholesterol imaging and computed tomography of the adrenal glands in differentiating the cause of Cushing's syndrome.

Measurement of 75Se-cholesterol (Scintadren) uptake and computed tomography (CT) of the adrenal glands were compared as a means of differentiating the cause of Cushing's syndrome in 11 patients over a 2-year period. Quantitative Scintadren imaging differentiated adrenocorticotrophic hormone (ACTH)-dependent disease from local adrenocortical lesions as the cause of Cushing's syndrome in all the patients studied. CT of the adrenal glands rapidly and accurately detected the adrenal mass lesions in 2 cases and was effective in documenting bilateral hyperplasia due to ectopic ACTH-dependent disease. However, in entopic ACTH (pituitary)-dependent disease the adrenal glands were of normal thickness in all but 2 patients, who had bilateral hyperplasia. Scintadren imaging and CT are useful non-invasive procedures for differentiating local adrenal disease from ACTH-dependent disease as the cause of Cushing's syndrome and should be the initial investigations once a firm clinical and biochemical diagnosis of Cushing's syndrome has been made.

Quantitative selenium-75-cholesterol imaging and computed tomography of the adrenal glands in Conn's syndrome.

Six consecutive patients with biochemically proven primary aldosteronism (4 with unilateral aldosteronomas and 2 with bilateral hyperplasia) underwent imaging with 75Se-selenomethyl-nor-cholesterol (Scintadren; Radiochemical Centre, Amersham, UK) and computed tomography (CT) of the adrenal glands to aid in lateralizing unilateral aldosterone-producing adenomas (APA) and to differentiate APA from idiopathic adrenal hyperplasia (IAH). Scintadren quantitative imaging alone was successful in lateralizing the lesion in all 4 cases of unilateral APA; mean uptake by the affected adrenal gland was 0.47% of the administered dose as against 0.23% in the normal gland (P less than 0.01). The mean uptake ratio for the adenomatous as against the normal gland was 2.03 (range 1.75-2.21), which was significantly greater than the uptake ratio of 0.82 in 4 normal individuals (P less than 0.01). CT lateralized all the APAs. In the 2 cases of IAH, Scintadren uptake was bilaterally increased in one case in which CT was normal, whereas in the other case Scintadren uptakes were normal while CT showed two abnormal glands. The overall diagnostic yield for Scintadren was 83%; the figure for CT was also 83%. When the results of Scintadren imaging and CT are pooled, the accuracy in lateralizing APAs and differentiating APA from IAH as a cause of Conn's syndrome is 100%.