Ultrasonographic characteristics of both adrenal glands in 15 dogs with functional adrenocortical tumors.

Ultrasonographic examination of both adrenal glands was performed in 15 dogs with functional adrenocortical tumors (FAT). Bilateral adrenal tumors were diagnosed in three of 15 dogs, and unilateral tumors were diagnosed in 12 of 15 dogs. Adrenal tumors were characterized by adrenal gland enlargement with loss of the normal shape and parenchymal structure. The contralateral adrenal gland could be imaged in all dogs with unilateral tumors. Based on size, shape, and parenchymal structure, the contralateral adrenal gland was similar to adrenal glands of normal dogs. The results of this study show that: 1) both adrenal glands should be imaged routinely in dogs with hyperadrenocorticism; 2) bilateral adrenocortical tumors seem to be more frequent than previously assumed; 3) one normal adrenal gland does not exclude the existence of a contralateral FAT; and 4) the functional atrophy of the contralateral adrenal gland in dogs with FAT may not be apparent ultrasonographically.     

Concurrent pituitary and adrenal tumors in dogs with hyperadrenocorticism: 17 cases (1978-1995).

OBJECTIVE: To describe the clinicopathologic characteristics of dogs with hyperadrenocorticism and concurrent pituitary and adrenal tumors. DESIGN: Retrospective study. ANIMALS: 17 client-owned dogs. PROCEDURE: Signalment, response to treatment, and results of CBC, serum biochemical analysis, urinalysis, endocrine testing, and histologic examinations were obtained from medical records of dogs with hyperadrenocorticism and concurrent adrenal and chromophobe pituitary tumors. RESULTS: On the basis of results of adrenal function tests and histologic examination of tissue specimens collected during surgery and necropsy, concurrent pituitary and adrenal tumors were identified in 17 of approximately 1,500 dogs with hyperadrenocorticism. Twelve were neutered females, 5 were males (3 sexually intact, 2 neutered); and median age was 12 years (range, 7 to 16 years). Hyperadrenocorticism had been diagnosed by use of low-dose dexamethasone suppression tests and ACTH stimulation tests. During high-dose dexamethasone suppression testing of 16 dogs, serum cortisol concentrations remained high in 11 dogs but decreased in 5 dogs. Plasma concentrations of endogenous ACTH were either high or within the higher limits of the reference range (12/16 dogs), within the lower limits of the reference range (2/16), or low (2/16). Adrenal lesions identified by histologic examination included unilateral cortical adenoma with contralateral hyperplasia (10/17), bilateral cortical adenomas (4/17), and unilateral carcinoma with contralateral hyperplasia (3/17). Pituitary lesions included a chromophobe microadenoma (12/17), macroadenoma (4/17), and carcinoma (1/17). CLINICAL IMPLICATIONS: Pituitary and adrenal tumors can coexist in dogs with hyperadrenocorticism, resulting in a confusing mixture of test results that may complicate diagnosis and treatment of hyperadrenocorticism.     

ADRENAL NEOPLASIA IN SEVEN FERRETS

Medical records from 7 ferrets presented to the VMTH with histologically confirmed adrenal neoplasia were reviewed. Three neutered female ferrets had adrenal cortical adenoma; four ferrets (2 neutered females, 2 neutered males) had adrenal cortical carcinoma. Ultrasound identified unilateral enlargement or abnormal shape of the adrenal gland in all ferrets. Only 1 ferret had adrenomegaly on abdominal radiographs. Adrenomegaly was identified in 1 ferret by magnetic resonance imaging (MRI). All ferrets were treated by adrenalectomy followed by a tapered dose of prednisone. Surgical complications were limited to fatal hemorrhage from the caudal vena cava in 1 ferret. Remission of clinical signs occurred in all 6 ferrets which survived surgery. The time of follow up varied from 3 to 16 months. The 3 ferrets with adrenal adenomas were still alive 3 to 7 months after surgery. AH 3 ferrets with adrenal carcinoma developed metastasis and were euthanized from 2 to 16 months after surgery.     

Hypofractionated radiation therapy for treatment of an adrenal mass in a ferret

Background: Ferret hyperadrenocorticism is the most common endocrine disease among domesticated ferrets. Current therapies include adrenalectomy and gonadotropin-releasing hormone analogs. Radiation therapy was used as an alternative noninvasive local therapy option. Case presentation: A 5-year-old male castrated ferret originally presented for pollakiuria. An abdominal ultrasound evaluation revealed an enlarged right adrenal gland with heterogenous parenchyma. Hypofractionated radiation therapy for treatment of the right adrenal mass was planned and performed using a small animal irradiator system. The prescribed radiation protocol was 30 Gray administered in 5 weekly fractions. The volume of the irradiated adrenal mass was serially quantified via the weekly cone beam CT. The adrenal mass volume decreased by 88% over the 10-month period. The ferret was euthanized 10 months postradiation therapy due to progressive co-morbidities, and the body was submitted for necropsy examination. No evidence of adrenal tissue or neoplastic tissue was found on histopathology of the irradiated right adrenal mass at the time of death. Evidence of systemic mycobacteriosis was discovered on necropsy. Conclusion and case relevance: Based on histopathologic evaluation, a complete response was achieved with hypofractionated radiation therapy of the right adrenal mass. Additional studies are needed to evaluate the safety and efficacy of this novel therapeutic approach.     

Hyperadrenocorticism associated with excessive sex hormone production by an adrenocortical tumor in two dogs.

An 11-year-old spayed female Labrador Retriever and a 9-year-old castrated male miniature Poodle were evaluated because of clinical signs of hyperadrenocorticism. Cortisol testing did not support a diagnosis of hypercortisolemia in either dog; however, imaging studies revealed unilateral adrenal tumors in both dogs. Serum concentrations of 17-hydroxyprogesterone, progesterone, and estradiol were high in both dogs, and androstenedione concentrations were also high in 1 dog. It is suspected that sex hormone secretion by the adrenal tumors in these dogs resulted in clinical signs of hyperadrenocorticism. Clinical signs and hormonal abnormalities resolved in the male dog after surgical resection of the tumor. There was no improvement in clinical signs after treatment with mitotane in the female dog, which died 2 months after diagnosis. Histologic evaluation confirmed the presence of adrenocortical carcinoma in both dogs.     

Long-term outcome of domestic ferrets treated surgically for hyperadrenocorticism: 130 cases (1995-2004)

OBJECTIVE: To determine the long-term survival rate and factors that affect survival time of domestic ferrets treated surgically for hyperadrenocorticism. STUDY DESIGN: Retrospective case series. ANIMALS: 130 ferrets with hyperadrenocorticism that were treated surgically. PROCEDURES: Medical records of ferrets surgically treated for hyperadrenocorticism were reviewed. Data recorded included signalment, duration of clinical signs prior to hospital admission, CBC values, serum biochemical analysis results, anesthetic time, surgical time, concurrent diseases, adrenal gland affected (right, left, or both [bilateral]), histopathologic diagnosis, surgical procedure, caudal vena caval involvement (yes or no), postoperative melena (yes or no), days in hospital after surgery, and whether clinical signs of hyperadrenocorticism developed after surgery. RESULTS: 130 ferrets were entered in the study (11 of 130 ferrets were admitted and underwent surgery twice). The 1- and 2-year survival rates were 98% and 88%, respectively. A 50% survival rate was never reached. Combined partial adrenal gland resection with cryosurgery had a significantly negative effect on survival time. No other risk factors were identified. Survival time was not significantly affected by either histopathologic diagnosis or specific affected adrenal gland (right, left, or bilateral). CONCLUSIONS AND CLINICAL RELEVANCE: Ferrets with adrenal gland masses that were treated surgically had a good prognosis. Survival time of ferrets with hyperadrenocorticism undergoing surgery was not affected by the histologic characteristic of the tumor, the adrenal glands affected (right, left, or bilateral), or complete versus partial adrenal gland resection. Debulking was a sufficient surgical technique to allow a favorable long-term outcome when complete excision was not possible.     

Leuprolide acetate treatment of adrenocortical disease in ferrets

OBJECTIVE: To determine the effects of leuprolide acetate, a long-acting gonadotropin-releasing hormone analog, in ferrets with adrenocortical diseases. DESIGN: Case series. ANIMALS: 20 ferrets with adrenocortical disease diagnosed on the basis of clinical signs and plasma sex hormone concentrations. PROCEDURE: Ferrets were treated with leuprolide (100 microg, IM, once), and plasma hormone concentrations were measured before and 3 to 6 weeks after treatment. RESULTS: Leuprolide treatment resulted in significant reductions in plasma estradiol, 17 alpha-hydroxyprogesterone, androstenedione, and dehydroepiandrosterone concentrations and eliminated or reduced clinical signs associated with adrenocortical disease. Decreases in vulvar swelling, pruritus, and undesirable sexual behaviors and aggression were evident 14 days after treatment; hair regrowth was evident by 4 weeks after treatment. The response to treatment was transitory, and clinical signs recurred in all ferrets. Mean +/- SEM time to recurrence was 3.7 +/- 0.4 months (range, 1.5 to 8 months). CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that leuprolide can be safely used to temporarily eliminate clinical signs and reduce sex hormone concentrations in ferrets with adrenocortical diseases. However, the safety of long-term leuprolide use in ferrets has not been investigated, and the long-term effects of leuprolide in ferrets with nodular adrenal gland hyperplasia or adrenal gland tumors are unknown.     

Ultrasonographic identification of vascular invasion by adrenal tumors in dogs

Adrenalectomy is the treatment of choice for adrenal tumors that are producing adverse clinical signs. Surgical planning prior to adrenalectomy is aided by identifying tumors with invasion into adjacent vessels or the presence of a tumor thrombus extending into the caudal vena cava. In this paper, we evaluated the sensitivity and specificity of ultrasound in determining if vascular invasion or tumor thrombus is present. Thirty-four dogs with 36 adrenal tumors were reviewed retrospectively. Overall, 36% of tumors had vascular invasion. Abdominal ultrasound was 100% sensitive and 96% specific in identifying the presence of a tumor thrombus in the caudal vena cava. The sensitivity and specificity was 76% and 96%, respectively, when all forms of vascular invasion were evaluated and included patients with vascular wall invasion without concurrent thrombus. Abdominal ultrasound is a good screening tool for identifying vascular invasion or tumor thrombus associated with adrenal tumors in dogs.     

Temporary tube cystostomy as a treatment for urinary obstruction secondary to adrenal disease in four ferrets

Adrenal neoplasia is a common problem in middle-aged to older ferrets. Male ferrets may present for stranguria and dysuria due to prostatic/paraurethral tissue enlargement secondary to elevation in androgens produced by the neoplastic tissue. Progressive urethral compression followed by complete urinary obstruction can result. Urinary obstruction can persist for days following surgery requiring urinary diversion. Four ferrets presenting with signs consistent with urinary obstruction secondary to adrenal disease were immediately treated with urethral catheterization or cystocentesis followed by adrenalectomy and temporary tube cystostomy. The tube cystostomy placement and use were associated with minimal complications and allowed recovery from surgery.     

RETROSPECTIVE REVIEW OF THE ULTRASONOGRAPHIC FEATURES OF ADRENAL LESIONS IN 21 FERRETS

Clinical signs and follow-up information were recorded. Histopathologic diagnoses were obtained for 25 adrenal glands in 21 ferrets. Adrenal lesions included ten adenocarcinomas, nine adenomas, one hyperplasia and one cortical cyst. Four adrenal glands (all right-sided) were diagnosed as unspecified adrenal tumors but lacked a definite histopathologic diagnosis (adenoma vs. adenocarcinoma) due to incomplete surgical resection and consequent small sample sizes. Bilateral adrenal lesions were identified in 4 ferrets (19%). Adrenal shape, size, echogenicity, laterality, and the presence of vascular invasion were evaluated with ultrasound. Size and shape were variable and not specific to lesion type. Both benign and malignant adrenal tumors (adenomas, adenocarcinomas) appeared most often as masses with increased thickness and a normal length (11/23), less frequently as larger masses with increased thickness and length (4/23) or as nodules focally deforming the normal adrenal shape (6/23). The only cortical cyst appeared as a nodule. Three adrenal glands had a normal size and shape and were diagnosed as adenomas (2) or hyperplasia (1). Therefore treatment may be warranted based solely on clinical signs if adrenal glands are ultrasonographically normal. Vascular invasion was not identified ultrasonographically. However, focal absence of periglandular fat resulting in contact of 8 adrenal glands with either caudal vena cava (6), aorta (1) or liver (1) identified ultrasonographically, correlated with incomplete surgical resectability (6/8) and histopathologic diagnoses of carcinoma (4/8) or unspecified tumors (4/8). Therefore, a focal absence of periglandular fat between the adrenal gland and the large vessels or liver, deviation or compression of the large vessels by the adrenal lesion may indicate malignancy. Adrenal tumors (benign and malignant) were often associated with a prominent uterus, uterine stump or prostate with or without prostatic cysts.     

Some functional characteristics of adrenal medullary tumors in aged male Wistar rats

Neither analysis of the urinary catecholamine metabolites vanillymandelic acid and 4-hydroxy-3-methoxyphenylglycol nor blood pressure measurements allowed the detection of adrenal medullary tumors or hyperplasia in 115 aged male Wistar rats (70 rats, 24 months of age and 45 rats, 30 months of age). Histochemical examination of the adrenal glands demonstrated that the 55 hyperplastic and 25 neoplastic lesions of the medulla usually had little or no chromaffinity. Chromaffinity was found comparable to normal medulla in only three tumors examined histochemically. Of these tumors, two were partially and one completely chromaffin-positive, but all three were small and did not result in elevated blood pressure or catecholamine metabolite excretion values. These observations indicate that excessive catecholamine synthesis and release is not a feature of adrenomedullary tumors and hyperplasia occurring spontaneously in aged male Wistar rats.     

Perianal adenomas and hypertestosteronemia in a spayed bitch with pituitary-dependent hyperadrenocorticism

Hypertestosteronemia was diagnosed in a spayed bitch with pituitary-dependent hyperadrenocorticism and perianal adenomas. Serum concentrations of cortisol and testosterone decreased after treatment with mitotane was instituted. Excessive testosterone in this dog was thought to have been produced by the adrenal cortex, possibly in response to excessive ACTH concentrations. Development of androgen- or estrogen-responsive tumors in castrated dogs may be an early indication of adrenocortical hyperfunction.     

Elective and emergency surgical management of adrenal gland tumors: 60 cases (1999-2006)

Sixty-one adrenal gland tumors were surgically removed from 60 dogs. Fifty-two dogs underwent elective adrenalectomy and 8 dogs underwent emergency adrenalectomy for acute adrenal hemorrhage. Size of adrenal tumors ranged from 10 mm to 80 mm. Histopathology confirmed a diagnosis of adrenocortical tumor in 47 dogs, 26 of which were malignant. Pheochromocytoma was diagnosed in 11 dogs. Six dogs had tumor invasion of the caudal vena cava. Of the seven dogs that did not survive the perioperative period, four underwent emergency adrenalectomy. No dogs with tumor invasion of the caudal vena cava died perioperatively. Perioperative morality rates were 5.7% for dogs that underwent elective adrenalectomy and 50% for dogs that underwent emergency adrenalectomy for acute adrenal hemorrhage. Median survival time was 492 days for the 53 dogs that survived the perioperative period. Of the factors analyzed, only adrenal tumor size and the presence of acute adrenal hemorrhage had predictive values for perioperative mortality. Those dogs that survived the perioperative period had extended survival times of up to 1,590 days. The mortality rate associated with elective adrenalectomy in dogs may be lower than previously reported. Dogs with very large tumors or acute adrenal hemorrhage may have a more guarded prognosis.     

Steroidogenic response of adrenal tissues after administration of ACTH to dogs with hypercortisolemia

OBJECTIVE: To evaluate adrenal sex hormone concentrations in neutered dogs with hypercortisolemia. DESIGN: Case series. ANIMALS: 11 neutered dogs with hypercortisolemia. PROCEDURE: Serum samples obtained before and 1 hour after administration of ACTH were evaluated for concentrations of cortisol, progesterone, testosterone, dehydroepiandrosterone sulfate or androstenedione or both, and 17-hydroxyprogesterone. RESULTS: For all dogs, concentrations of 1 or more adrenal sex hormones were substantially greater than reference range values before or after administration of ACTH. Testosterone concentration was not greater than reference range values in any of the dogs. CONCLUSIONS AND CLINICAL RELEVANCE: Results emphasize the importance of ruling out hypercortisolemia before measuring adrenal sex hormone concentrations as a means of diagnosing adrenal hyperplasia syndrome (alopecia X) in dogs.     

Surgical Management of Adrenal Tumors and Insulinomas in Ferrets

Domestic ferrets are popular pets and comprise a significant percentage of the caseload in many veterinary practices. This article describes the diagnosis and surgical techniques for treatment of 2 common endocrine disorders affecting ferrets, adrenal gland disease and pancreatic beta cell neoplasms. Although medical treatment options are used to reduce the severity of clinical signs associated with adrenal hyperplasia or neoplasia, surgical removal of the adrenal gland(s) is the treatment of choice. Clinical disease associated with pancreatic beta cell tumors includes hypoglycemia, and in many cases the tumor will metastasize early in the course of the disease. Although achieving a complete resolution of pancreatic beta cell neoplasia is unlikely, surgical removal of insulin-secreting tumors is recommended to temporarily alleviate the clinical syndrome and confirm the diagnosis.     

Computed tomography in the diagnosis of canine hyperadrenocorticism not suppressible by dexamethasone

Computed tomography (CT) was performed in 10 dogs with hyperadrenocorticism not suppressible by dexamethasone. In 6 of these dogs, a unilateral adrenal mass was found on CT images. Specimens of the masses were obtained via retroperitoneal laparotomy; histologic examination revealed 4 carcinomas, 1 adenoma, and 1 nodular hyperplasia. In the 4 other dogs, CT revealed symmetric bilateral adrenal gland enlargement. In 2 of these dogs, contrast-enhanced CT revealed a mass in the pituitary fossa, which could be identified at necropsy as a pituitary tumor. The other 2 dogs were successfully treated with mitotane.     

Clinical and endocrine responses to treatment with deslorelin acetate implants in ferrets with adrenocortical disease

OBJECTIVE: To evaluate the clinical and endocrine responses of ferrets with adrenocortical disease (ACD) to treatment with a slow-release implant of deslorelin acetate. ANIMALS: 15 ferrets with ACD. PROCEDURE: Ferrets were treated SC with a single slow-release, 3-mg implant of deslorelin acetate. Plasma estradiol, androstenedione, and 17-hydroxyprogesterone concentrations were measured before and after treatment and at relapse of clinical signs; at that time, the adrenal glands were grossly or ultrasonographically measured and affected glands that were surgically removed were examined histologically. RESULTS: Compared with findings before deslorelin treatment, vulvar swelling, pruritus, sexual behaviors, and aggression were significantly decreased or eliminated within 14 days of implantation; hair regrowth was evident 4 to 6 weeks after treatment. Within 1 month of treatment, plasma hormone concentrations significantly decreased and remained decreased until clinical relapse. Mean time to recurrence of clinical signs was 13.7 +/- 3.5 months (range, 8.5 to 20.5 months). In 5 ferrets, large palpable tumors developed within 2 months of clinical relapse; 3 of these ferrets were euthanatized because of adrenal gland tumor metastasis to the liver or tumor necrosis. CONCLUSIONS AND CLINICAL RELEVANCE: In ferrets with ACD, a slow-release deslorelin implant appears promising as a treatment to temporarily eliminate clinical signs and decrease plasma steroid hormone concentrations. Deslorelin may not decrease adrenal tumor growth in some treated ferrets. Deslorelin implants may be useful in the long-term management of hormone-induced sequelae in ferrets with ACD and in treatment of animals that are considered at surgical or anesthetic risk.     

Canine hyperadrenocorticism

Hyperadrenocorticism is a common endocrinopathy which results from the excessive production of cortisol by the adrenal cortex. In the majority of cases, this increased secretion of cortisol results from stimulation of the adrenal cortex by adrenocorticotrophic hormone secreted from the pituitary gland. In a smaller number of cases adrenal tumours are present. Clinical signs are variable but commonly include polydipsia and polyuria, polyphagia, obesity, a pendulous abdomen, hepatomegaly, alopecia, lethargy, weakness and anoestrus. Haematology, serum chemistry analysis and urinalysis should be performed on a dog with suspected hyperadrenocorticism. Finding a significant number of changes that are consistent with hyperadrenocorticism often allows a presumptive diagnosis to be made. Other tests can then be used to confirm the diagnosis and to help localise the cause, including liver biopsy, radiology, ultrasonography, gamma camera imaging, computed tomography, and measurement of blood and urine hormone levels. The ACTH stimulation test, low dose dexamethasone suppression test and measurement of the urine cortisol:creatinine ratio are used to assess whether hyperadrenocorticism is present. The high dose dexamethasone suppression test, measurement of plasma ACTH, corticotropin-releasing hormone stimulation test, and a modification of the urinary cortisol:creatinine ratio test are then implemented to determine the aetiology. The treatment of choice for adrenal neoplasia is surgical removal of the affected adrenal. On the other hand, pituitary hyperplasia or neoplasia may be treated either surgically, by bilateral adrenalectomy or hypophysectomy, or medically. The drug which is chosen most commonly for medical management is 1,1-dichloro-2(O-chlorophenyl)-2-(P-chlorophenyl) ethane (op'-DDD), which can be used to suppress adrenal function or to completely destroy the adrenal cortex. The antifungal agent ketoconazole also suppresses adrenal steroid synthesis and provides an alternative form of medical treatment for hyperadrenocorticoid dogs.     

Male pseudohermaphroditism, cryptorchism, and Sertoli cell neoplasia in three miniature Schnauzers.

A syndrome of male pseudohermaphroditism, cryptorchidism, and testicular neoplasia was diagnosed in 3 Miniature Schnauzers. The dogs had clinical signs of hyperestrogenism and were either unilateral or bilateral cryptorchids. At surgery, it was discovered that the dogs were male pseudohermaphrodites, having intra-abdominal testes containing Sertoli cell tumors and uteri that had undergone endometrial cystic hyperplasia.     

Ultrasonographic visualization of the adrenal glands of healthy ferrets and ferrets with hyperadrenocorticism

A protocol was developed to compare the ultrasonographic characteristics of the adrenal glands of 21 healthy ferrets and 37 ferrets with hyperadrenocorticism. By using specific landmarks, the adrenal glands were imaged in 97% of the cases. The adrenal glands of ferrets with hyperadrenocorticism had a significantly increased thickness, with changes in shape, structure, and echogenicity compared to the adrenal glands of healthy ferrets. Based on the findings of the study, adrenal glands may be classified as abnormal when they have a rounded appearance, increased size of the cranial/caudal pole (thickness >3.9 mm), a heterogeneous structure, increased echogenicity, and/or signs of mineralization.