Adrenalectomy for the treatment of hypotension in a cat with phaeochromocytoma associated with caudal vena cava syndrome

An 11-year-old spayed female, Persian cat was referred to the Jeonbuk Animal Medical Center for evaluation of a 2-month history of lethargy and anorexia. Physical examination revealed tachycardia and hypotension. Abdominal imaging via sonography and CT identified a right adrenal gland mass causing severe deviation and compression of the caudal vena cava. After stabilising the blood pressure and heart rate through positive inotropes and fluid therapy, right adrenalectomy was performed. Surgery confirmed the adrenal gland mass was severely compressing the caudal vena cava. Histopathological examination revealed that the mass was a pheochromocytoma. After adrenalectomy, blood pressure and heart rate stabilised and remained unaffected 8 months postsurgery. This report describes a rare case of an adrenal pheochromocytoma leading to caudal vena cava compression in a cat presenting with hypotension.

MicroRNA-194-5p/Heparin-binding EGF-like growth factor signaling mediates dexamethasone-induced activation of pseudorabies virus in rat pheochromocytoma cells

Pseudorabies virus (PRV) is a neurotropic virus, which infects a wide range of mammals. The activity of PRV is gradually suppressed in hosts that have tolerated the primary infection. Increased glucocorticoid levels resulting from stressful stimuli overcome repression of PRV activity. However, the host cell mechanism involved in the activation processes under stressful conditions remains unclear. In this study, infection of rat PC-12 pheochromocytoma cells with neuronal properties using PRV at a multiplicity of infection (MOI) = 1 for 24 h made the activity of PRV be the relatively repressed state, and then incubation with 0.5 μM of the corticosteroid dexamethasone (DEX) for 4 h overcomes the relative repression of PRV activity. RNA-seq deep sequencing and bioinformatics analyses revealed different microRNA and mRNA profiles of PC-12 cells with/without PRV and/or DEX treatment. qRT-PCR and western blot analyses confirmed the negative regulatory relationship of miRNA-194-5p and its target heparin-binding EGF-like growth factor (Hbegf); a dual-luciferase reporter assay revealed that Hbegf is directly targeted by miRNA-194-5p. Further, miRNA-194-5p mock transfection contributed to PRV activation, Hbegf was downregulated in DEX-treated PRV infection cells, and Hbegf overexpression contributed to returning activated PRV to the repression state. Moreover, miRNA-194-5p overexpression resulted in reduced levels of HBEGF, c-JUN, and p-EGFR, whereas Hbegf overexpression suppressed the reduction caused by miRNA-194-5p overexpression. Overall, this study is the first to report that changes in the miR-194-5p-HBEGF/EGFR pathway in neurons are involved in DEX-induced activation of PRV, laying a foundation for the clinical prevention of stress-induced PRV activation.

Ectopic adrenal tissue in a cat that underwent an ovariohysterectomy

OBJECTIVE

To describe the use of ultrasound and adrenal function testing to confirm that excised periovarian tissue is normal ectopic adrenal tissue (EAT).

ANIMAL

A 6-month-old female domestic shorthair cat.

CLINICAL PRESENTATION, PROGRESSION, AND PROCEDURES

The cat underwent an ovariohysterectomy procedure, during which abnormal tissue was discovered adjacent to both ovaries. The tissue was removed during the ovariohysterectomy and submitted for histopathology, which was consistent with adrenal gland tissue, initially raising concern for an inadvertent adrenalectomy. Abdominal ultrasound and an adrenal function test were performed that confirmed normal adrenal structure and function; thus, the removed structure was diagnosed as EAT.

TREATMENT AND OUTCOME

The patient continued to recover from the procedure uneventfully at home.

CLINICAL RELEVANCE

Parovarian nodules are an uncommon finding but when observed and biopsied, may be mistaken for physiologic adrenal tissue on the basis of histopathologic features alone without awareness of their existence and clinical context. The use of abdominal ultrasound and ACTH stimulation test offers an affirmative method of differentiating adrenal gland tissue from EAT.

Risk factors influencing death prior to discharge in 302 dogs undergoing unilateral adrenalectomy for treatment of primary adrenal gland tumours

Adrenalectomies for canine adrenal tumours are associated with peri-operative morbidity and mortality. Objectives of this study included assessing the prognostic value of tumour- or surgery-related variables in predicting peri-operative mortality and overall survival in dogs undergoing adrenalectomies for primary adrenal tumours as well as pre-treatment with phenoxybenzamine on survival to discharge with pheochromocytomas specifically. A multi-institutional retrospective cohort study was performed across nine institutions. Electronic medical record searches identified 302 dogs which met the inclusion criteria. Data collected included dog-related, tumour-related, treatment-related, surgery-related, and outcome variables. Univariate and multivariable logistic regression and cox proportional hazards models were used to identify variables associated with death prior to discharge and tumour-related survival. Overall, 87% of dogs survived to discharge with a tumour-related survival time of 3.96 years. Post-operative complications were reported in 25%. Increased surgical time (p = 0.002) and pre-surgical medical treatment other than phenoxybenzamine (p = 0.024) were significantly associated with increased peri-operative mortality while ureteronephrectomy (p = 0.021), post-operative pancreatitis (p = 0.025), and post-operative aspiration pneumonia (p < 0.001) were significantly associated with decreased overall survival. Phenoxybenzamine pretreatment had no effect on peri-operative mortality. Thirty-seven of 45 (82%) dogs with pheochromocytomas not pretreated survived to discharge, and 50 of 59 (85%) dogs with pheochromocytomas pretreated with phenoxybenzamine survived to discharge (p = 0.730). This study provides information on risk factors for death prior to discharge and tumour-related survival that may help guide clinical management and owner expectations. In addition, the study findings challenge the previously reported benefit of phenoxybenzamine for pretreatment of dogs undergoing adrenalectomies for pheochromocytomas.

Adrenal tumors treated by adrenalectomy following spontaneous rupture carry an overall favorable prognosis: retrospective evaluation of outcomes in 59 dogs and 3 cats (2000-2021)

OBJECTIVE

To conduct a retrospective multi-institutional study reporting short- and long-term outcomes of adrenalectomy in patients presenting with acute hemorrhage secondary to spontaneous adrenal rupture.

ANIMALS

59 dogs and 3 cats.

METHODS

Medical records of dogs and cats undergoing adrenalectomy between 2000 and 2021 for ruptured adrenal masses were reviewed. Data collected included clinical presentation, preoperative diagnostics, surgical report, anesthesia and hospitalization findings, histopathology, adjuvant treatments, and long-term outcome (recurrence, metastasis, and survival).

RESULTS

Median time from hospital admission to surgery was 3 days, with 34% of surgeries being performed emergently (within 1 day of presentation). Need for intraoperative blood transfusion was significantly associated with emergent surgery and presence of active intraoperative hemorrhage. The short-term (≤ 14 days) complication and mortality rates were 42% and 21%, respectively. Negative prognostic factors for short-term survival included emergent surgery, intraoperative hypotension, and performing additional surgical procedures. Diagnoses included adrenocortical neoplasia (malignant [41%], benign [12%], and undetermined [5%]), pheochromocytoma (38%), a single case of adrenal fibrosis and hemorrhage (2%), and a single case of hemangiosarcoma (2%). Local recurrence and metastasis of adrenocortical carcinoma were confirmed in 1 and 3 cases, respectively. Overall median survival time was 574 days and 900 days when short-term mortality was censored. No significant relationship was found between histopathological diagnosis and survival.

CLINICAL RELEVANCE

Adrenalectomy for ruptured adrenal gland masses was associated with similar short- and long-term outcomes as compared with previously reported nonruptured cases. If hemodynamic stability can be achieved, delaying surgery and limiting additional procedures appear indicated to optimize short-term survival.

Laparoscopic adrenalectomy for resection of unilateral noninvasive adrenal masses in dogs is associated with excellent outcomes in experienced centers

OBJECTIVE

To report the short- and long-term outcomes of laparoscopic adrenalectomy (LA) for resection of unilateral adrenal masses and to document risk factors for conversion and peri- and postoperative morbidity.

ANIMALS

255 client-owned dogs.

METHODS

Dogs were included if LA was attempted for resection of a unilateral adrenal mass. Medical records were evaluated and relevant data were reported, including complications, conversion, perioperative death, and long-term outcomes. Signalment, clinicopathological data, and surgical experience were factors statistically evaluated for possible associations with capsular penetration during surgery, conversion, surgical time, duration of hospital stay, death prior to discharge, mass recurrence, and survival time.

RESULTS

155 dogs had left-sided tumors, and 100 had right-sided tumors. Conversion to an open approach was performed in 9.4% of cases. Capsular penetration (19.2%) and major hemorrhage (5.4%) were the most prevalent intraoperative complications. Of the dogs operated on, 94.9% were discharged from the hospital. Lesion side, portion of the gland affected, and surgeon experience influenced surgical time. Conversion rate increased with increasing body condition score and lesion size. Risk of death prior to discharge increased with increasing lesion size. Risk of conversion and death prior to discharge were lower when performed by more experienced surgeons. Capsular penetration during LA increased the risk of tumor recurrence.

CLINICAL RELEVANCE

LA for resection of unilateral adrenal masses is associated with excellent outcomes in experienced centers. Surgeons with greater experience with LA have lower surgical times, conversion rates, and risk of death prior to discharge.

Successful treatment of acute respiratory failure following hypertensive crisis in a dog with presumed pheochromocytoma or paraganglioma

Background

Acute respiratory failure has been reported as one of the manifestations of hypertensive crisis in pheochromocytoma in human medicine. In dogs, no reports have been described as acute respiratory failure following hypertensive crisis. Here, we report the clinical presentation, course, and treatment of acute respiratory failure following the hypertensive crisis in a dog with presumed pheochromocytoma or paraganglioma.

Case Description

A 12-year-old neutered male toy poodle was referred for the diagnostic evaluation of a right adrenal gland mass. The dog suddenly exhibited severe dyspnea with abnormal hypertension (systolic blood pressure >200 mmHg) 15 minutes after recovery from the anesthesia for the computed tomography (CT) examination. Pulmonary CT and ultrasonography findings suggested acute onset of severe pulmonary edema. Pulmonary edema was treated with mechanical ventilation (pressure-support ventilation with continuous positive airway pressure) and negative fluid balance after the administration of furosemide. Weaning from mechanical ventilation was successful 24 hours after the onset of respiratory failure. Finally, the dog was discharged 3 days after weaning from ventilation without complications.

Conclusion

This report outlines a case of acute respiratory failure following a hypertensive crisis requiring mechanical ventilatory management in a dog. The onset and progression of pulmonary edema were extremely rapid. However, improvement in pulmonary edema was also rapid. Hemodynamic stability, in addition to prompt diagnosis and aggressive therapeutic intervention, including mechanical ventilation, may have contributed to the good prognosis of pulmonary edema following hypertensive crisis in a dog, which we attribute to a catecholamine storm.

Bilateral, single-session, laparoscopic adrenalectomy was associated with favorable outcomes in a cohort of dogs

OBJECTIVE

To report perioperative characteristics and outcome following bilateral, single-session, laparoscopic adrenalectomy (BSSLA) in dogs.

ANIMALS

Client-owned dogs (n = 6).

CLINICAL PRESENTATION AND PROCEDURES

Medical records were reviewed and perioperative data collected, including preoperative diagnostic imaging, operative details, complications, and need for conversion to open laparotomy. Bilateral, single-session, laparoscopic adrenalectomy was performed on the right or left side with a standard 3- or 4-portal transperitoneal technique. The dog was repositioned to contralateral recumbency, and laparoscopic adrenalectomy was repeated. Follow-up information was collected by telephone interviews with the owners and/or referring veterinarian.

RESULTS

Median age and weight of dogs were 126 months and 14.75 kg, respectively. Contrast-enhanced CT (CECT) was performed in all dogs. Median maximal tumor diameter was 2.6 and 2.3 cm for the right and left-sided tumors, respectively. Median surgical and anesthesia times were 158 and 240 minutes, respectively. Conversion to open laparotomy was performed in 1 dog following renal vein laceration during initial adrenalectomy. Left adrenalectomy and ureteronephrectomy were performed, and the right adrenal tumor was left in situ. Cardiac arrest occurred in 1 dog following initial adrenalectomy (left); however, the dog was resuscitated successfully, and contralateral laparoscopic adrenalectomy was performed without complication. All dogs survived to hospital discharge. Follow-up ranged from 60 to 730 days (median, 264 days) for dogs that successfully underwent BSSLA.

CLINICAL RELEVANCE

BSSLA was associated with favorable outcomes in this cohort of dogs. Laparoscopy may be considered in dogs with bilateral, modestly sized, noninvasive adrenal tumors.

Diagnosis, treatment and outcome of pheochromocytoma in a cat

Pheochromocytoma in cats is a rare clinical condition characterised by the development of a secretory endocrine tumour that arises from the adrenal medulla. An 8-year-old castrated male, domestic shorthair cat was referred for further investigation of a 4-month history of progressive weight loss with normal appetite, polyuria/polydipsia, generalised weakness, and severe hypertension. Sonography and computed tomography of the abdomen disclosed a mass arising from the left adrenal gland. The contralateral adrenal gland was normal in size and shape. Results from a low dose dexamethasone suppression test and measurements of plasma aldosterone concentration and plasma renin activity ruled out a cortisol-secreting tumour and aldosteronoma. The clinical presentation made a sex-steroid secreting tumour unlikely. Increased plasma metanephrine and normetanephrine concentrations prioritised the differential diagnosis of pheochromocytoma. The cat underwent adrenalectomy of the left gland and histopathological diagnosis with immunohistochemical markers confirmed the diagnosis.

Algorithmic estimation of adrenal volume based on body weight and CT landmarks in dogs

Computed tomographic (CT) methods for quantifying adrenal size are helpful for identifying and directing management of adrenal disease in dogs. This retrospective, observational study aimed to use CT to determine anatomic landmarks associated with adrenal gland volume in dogs, and subsequently develop an algorithm to estimate adrenal volume for individual subjects. Abdominal CT images from 150 dogs without adrenal disease were assessed. The volume of the left and right adrenals, as well as dimensions from anatomic structures, were measured. Predictive models for adrenal volume were examined with cross validation. A further 29 dogs were used for external validation and model fit. Dogs in the test cohort weighed from 3.1 to 67.5 kg (mean 24.4 kg) with left (VLA ) and right (VRA ) adrenal volume ranging from 0.23 to 2.84 cm3 (mean 1.22 cm3 ) and 0.14 to 2.97 cm3 (mean 1.11 cm3 ), respectively. A predictive model for each adrenal based on weight (W) and L1 height (HL1 ) best explained the adrenal volume, with external validation confirming model fit. The final models, adjusted for bias, were: VLA  = 0.154 + (0.02 × W) + (0.07 × HL1 ) (adjR2  = 0.62); and VRA  = -0.116 + (0.02 × W) + (0.06 × HL1 ) (adjR2  = 0.64). In dogs undergoing CT, these algorithms can be used to estimate expected adrenal volume and allow comparison with the actual volume measured on CT, facilitating interpretation of CT findings, and clinical decision-making.

Surgical management of an adrenal gland tumor that had extended into the thoracic portion of the caudal vena cava in a dog

CASE DESCRIPTION

A 14-year-old neutered female Border Collie with a 3-week history of collapse during exercise was evaluated because of recumbency, tachycardia, and hypotension.

CLINICAL FINDINGS

Results of biochemical testing indicated the presence of a pheochromocytoma, and CT revealed an enlarged right adrenal gland mass that extended down the right phrenicoabdominal vein into the posthepatic thoracic portion of the caudal vena cava.

TREATMENT AND OUTCOME

A midline celiotomy and median sternotomy were performed to allow en bloc removal of the right adrenal gland tumor and its tumor thrombus extension within the caudal vena cava. Temporary occlusion of the thoracic and abdominal portions of the caudal vena cava and both renal veins and the dual inflow to the liver (Pringle maneuver) were required. The venotomy and tumor and thrombus extractions required a 25-minute period of vascular occlusion. The dog had no major postsurgical complications. Histologic findings indicated that direct adrenal tumor invasion into the caudal vena cava wall had occurred along the established route of tumor extension down the phrenicoabdominal vein.

CLINICAL RELEVANCE

For the dog of this report, an adrenal tumor thrombus that extended into the thoracic portion of the caudal vena cava was surgically managed with a combined median sternotomy and midline celiotomy approach and temporary occlusion of the hepatic artery, portal vein, and abdominal and thoracic portions of the caudal vena cava. This facilitated successful manual manipulation of the tumor and enabled venotomy of sufficient size for tumor thrombus extraction.

Cholangiocarcinoma in a Free-Ranging Eurasian Brown Bear (Ursus arctos arctos) from Northern Spain

A hepatic cholangiocarcinoma with metastases in the gallbladder, left elbow joint, adrenal glands, and lungs was observed in a female 21-yr-old free-ranging Eurasian brown bear (Ursus arctos arctos) found in the Principality of Asturias (northern Spain). Gross and histopathologic findings are described.

Sex-hormone producing adrenal tumors causing behavioral changes as the sole clinical sign in 3 cats

Three neutered cats with adrenocortical tumors that were presented with behavioral changes but no evidence of hyperaldosteronism or hypercortisolism are described. All 3 cats had resolution of their clinical signs following adrenalectomy. For neutered cats presenting with behavior changes, a sex-hormone secreting adrenal tumor should be considered as a differential diagnosis.

Retrospective evaluation of toceranib phosphate (Palladia®) use in the treatment of inoperable, metastatic, or recurrent canine pheochromocytomas: 5 dogs (2014-2017)

BACKGROUND

Effective treatment options for inoperable, metastatic, or recurrent canine pheochromocytomas are lacking. In humans, specific germline mutations exist that drive the development of pheochromocytomas. Pharmaceutical blockade of these abnormalities with small molecule inhibitors are an effective treatment strategy. Similar mutations may exist in the dog, and thus, treatment with similar small molecule inhibitors may provide a survival advantage. The purpose of this study was to assess the role of toceranib phosphate in the treatment of inoperable, metastatic, or recurrent canine pheochromocytomas.

RESULTS

Retrospectively, medical records of dogs that had a diagnosis or suspect diagnosis of a pheochromocytoma were reviewed for information regarding response to toceranib phosphate and overall outcome. Five dogs were identified that fit the inclusion criteria. All five experienced clinical benefit (1 partial response, 4 stable disease). Progression-free interval (PFI) for the dog with the partial response was 61 weeks. PFI for the two dogs with stable measurable disease were 36 weeks and 28 weeks. PFI in the two dogs with stable metastatic disease were at least 11 weeks and 18 weeks.

CONCLUSIONS

Based on this limited series of dogs, the results suggest that toceranib may have biological activity in dogs with primary and metastatic pheochromocytomas. Larger studies are needed to define the use and response to toceranib in dogs with gross, microscopic, and metastatic pheochromocytoma.

Prevalence of adrenal gland masses as incidental findings during abdominal computed tomography in dogs: 270 cases (2013-2014)

OBJECTIVE To determine the prevalence and clinical characteristics of incidental adrenal gland masses identified in dogs undergoing abdominal CT. DESIGN Retrospective case series. ANIMALS 270 client-owned dogs. PROCEDURES Medical records of dogs that underwent abdominal CT from June 2013 through June 2014 were reviewed. Patients were excluded if they had undergone CT because of a history or clinical signs of an adrenal gland mass or disease. Information collected included history, signalment, initial complaint, serum alkaline phosphatase activity, urine specific gravity, and whether abdominal ultrasonography was performed. Imaging reports generated by the board-certified radiologist who evaluated the CT images were reviewed. RESULTS Incidental adrenal gland masses were detected in 25 of the 270 (9.3%) dogs. Dogs with incidental adrenal gland masses were significantly older (median, 12.0 years; range, 8.0 to 15.0 years) than dogs without (8.2 years; range, 0.1 to 13.1 years). Dogs examined for neoplasia were significantly more likely to have an incidental adrenal gland mass (22/138 [15.9%]) than were dogs examined for any other reason (3/132 [2.3%]), but these dogs were also significantly older. No other risk factors were identified. Histologic examination was performed in only 3 of the 25 dogs with incidental adrenal gland masses; 2 had cortical adenomas and 1 had a pheochromocytoma and cortical adenoma. CONCLUSIONS AND CLINICAL RELEVANCE Results suggested that a clinically important percentage of dogs undergoing abdominal CT will have incidental adrenal gland masses, with incidental masses more likely in older than in younger dogs.

Malignant Seminoma with Metastasis, Sertoli Cell Tumor, and Pheochromocytoma in a Spotted Dolphin (Stenella frontalis) and Malignant Seminoma with Metastasis in a Bottlenose Dolphin (Tursiops truncatus)

Seminoma with metastasis was diagnosed in a spotted dolphin ( Stenella frontalis) and an Atlantic bottlenose dolphin ( Tursiops truncatus). Sertoli cell tumor and pheochromocytoma were also diagnosed in the spotted dolphin. The spotted and bottlenose dolphins were adult males that stranded and died on the coasts of northwest Florida and southeast North carolina, respectively. Neoplasia is infrequently reported in cetaceans. This is the first report of seminoma, Sertoli cell tumor, and pheochromocytoma in a dolphin, the first report of three distinct neoplasms in a dolphin, and one of the few reports of malignant neoplasia in dolphins.

Adrenal Myelolipoma in a Dog

Abdominal ultrasound examination in an 11-year-old, intact, female Labrador dog with hepatic disease revealed a nodular swelling of the left adrenal gland. Hyperadrenocorticism was suspected, but endocrine tests were negative. At the owner's request, an adrenalectomy was performed. Grossly, a nodular mass protruded from the external surface of the left adrenal gland and in cut section was hemorrhagic and effaced the cortical and medullary regions. Histologic examination revealed a cortical neoplasm with medullary involvement. The mass was composed of well-differentiated adipose cells, megakaryocytes, hematopoietic cells, and macrophages containing hemosiderin deposits. A diagnosis of cortical adrenal myelolipoma was made.

Functional ectopic adrenal carcinoma in a dog

An 11-year-old spayed female pit bull terrier was presented with a 2-month history of polyuria, polydipsia, polyphagia, and panting. Serum chemistry, blood and urine analysis, and tests for hyperadrenocorticism suggested an adrenal tumor. Abdominal ultrasound identified a mass caudal to the right kidney. The mass was completely excised and histopathology was consistent with endocrine carcinoma. Three years later there was no evidence of recurrence or metastasis.

Gonadectomy-related adrenocortical tumors in ferrets demonstrate increased expression of androgen and estrogen synthesizing enzymes together with high inhibin expression

The 2 objectives of this study were to (1) measure by quantitative polymerase chain reaction the expression of genes involved in steroid and inhibin synthesis in adrenocortical tumors of gonadectomized ferrets and (2) localize by immunohistochemistry several proteins that are key to adrenal steroidogenesis. Relative to the control adrenals, expression of the messenger RNAs encoding StAR (steroidogenic acute regulatory protein; P = 0.039), CYP11A (P = 0.019), CYP21 (P = 0.01), and 3β-HSD (P = 0.004), all involved in the synthesis of mineralocorticoids and glucocorticoids, were decreased in the adrenocortical tumors. In contrast, expression of cytochrome B5 (CytB5; P = 0.0001) and aromatase (P = 0.003), involved in androgen and estrogen synthesis, and both inhibin α-subunit (P = 0.002) and βB-subunit (P = 0.001) were upregulated. In tumors, immunostaining of CYP21 was low, whereas staining of Cyp17 and CytB5, necessary for androgen synthesis, was present. It is concluded that ferret adrenocortical tumors express genes for androgen production. In addition, the expression of aromatase and inhibin suggests an even more gonadal differentiation, which is reminiscent to the fact that both gonads and adrenals are derived from a common urogenital primordial cell.

Metabolic complications of endocrine surgery in companion animals

Metabolic complications of endocrine surgery occur commonly and precautions should be taken to avoid potentially life-threatening situations and to lessen expense associated with a more extended hospital stay. Common complications of endocrine surgery as well as prevention strategies will be reviewed for pancreatic, parathyroid, and adrenal surgery.

The desmopressin stimulation test in dogs with Cushing's syndrome

Desmopressin is a synthetic analogue of the hypothalamic peptide vasopressin and binds to specific pituitary vasopressin (V3) receptors. The V3-receptor is overexpressed in pituitary corticotrope tumors and the injection of desmopressin induces a marked ACTH and cortisol release in human patients with pituitary- (PDH), but not adrenal tumor (AT) dependent hyperadrenocorticism. In this prospective study, we investigated the effects of desmopressin on serum cortisol levels in 80 dogs suspected of Cushing's syndrome. The aim was to find a sensitive and specific test to exclude AT. According to standard tests the dogs were divided into 3 groups (group 1=other disease, n=27; group 2=PDH, n=46; group 3=AT, n=7). Desmopressin was injected as an i.v. bolus of 4microg and serial blood samples were collected before and after 30, 60 and 90min. Desmopressin significantly stimulated cortisol release in dogs with PDH (median 51%, range -24 to 563%; p<0.0001), whereas no increase was seen in dogs with AT (median -12%, range -44 to 5%; p=0.063) and in controls (median +7%, range -36 to 196%; p=0.131). Using a cut off value of 10% increase over baseline, it was possible to exclude AT in 75% of patients. The results of this study suggest that the desmopressin test could be a useful tool in differentiating pituitary from adrenal dependent Cushing's syndromes. Additional dogs with adrenocortical tumor must be tested in order to recommend its use in clinical practice.

Adrenalectomy and Caval Thrombectomy in a Cat With Primary Hyperaldosteronism

A 13-year-old, castrated male, domestic longhaired cat was diagnosed with primary hyperaldosteronism from an adrenal gland tumor and a thrombus in the caudal vena cava. Clinical signs included cervical ventriflexion, lethargy, weakness, inappetence, and diarrhea. Laboratory tests revealed hypokalemia, normonatremia, hyperglycemia, hypophosphatemia, and elevated creatine kinase activity. Hypokalemia worsened despite oral potassium supplementation. An adrenalectomy and caval thrombectomy were successfully performed utilizing deliberate hypothermia followed by progressive rewarming.

[A phaeochromocytoma in a Lhasa Apso dog]

This report describes a case of phaeochromocytoma in an intact male Lhasa Apso dog of nearly 10 years old. The dog was suffering from acute lethargy and vomiting. After a successfully performed surgery and concurrent medication, to restore a temporary Addison s disease, the dog is doing clinically well six months later without any remaining symptoms.

IMAGING DIAGNOSIS-BILATERAL ADRENAL ADENOMAS AND MYELOLIPOMAS IN A DOG

A 10-year-old neutered female Pug was evaluated for a left adrenal mass detected previously by ultrasonography. Using computed tomography, a fat-attenuating, rim-enhancing left adrenal mass and a homogeneous, soft-tissue attenuating, intensely enhancing right adrenal mass were found. A left adrenalectomy and right adrenal biopsy were performed and the final diagnosis was bilateral adrenal adenomas and myelolipomas. Myelolipomas are rare, benign, endocrinologically inactive tumors composed of well-differentiated adipose tissue and a variable amount of hematopoietic cells of both lymphatic and myeloid lineages, which may account for the different appearance on tomographic images.

Epidural Spinal Myelolipoma in a Dog

Epidural spinal myelolipoma was diagnosed in a 13-year-old, male Siberian husky that was referred for evaluation of progressive pelvic limb paresis and urinary incontinence. An epidural mass was detected by magnetic resonance imaging and computed tomography. The mass was removed and identified histopathologically as an epidural myelolipoma. Pelvic limb paresis improved after surgery, but urinary retention associated with neurological bladder dysfunction persisted.

Unusual presentation of splenic myelolipoma in a dog

A 13-year-old dog was presented with clinical signs of anemia, vomiting, weight loss, and progressive abdominal distension. Abdominal ultrasonography and radiography revealed a large mass, which was removed surgically. Cytologic and histologic evaluation of the mass revealed a mixture of fat and hematopoietic tissue, consistent with a splenic myelolipoma.

Evaluation of a comparative pathogenesis between cancer-associated retinopathy in humans and sudden acquired retinal degeneration syndrome in dogs via diagnostic imaging and western blot analysis

OBJECTIVE

To evaluate dogs with sudden acquired retinal degeneration syndrome (SARDS) for evidence of pituitary gland, adrenal gland, and pulmonary neoplasia and antiretinal antibodies and to evaluate dogs with neoplasia for antiretinal antibodies.

ANIMALS

57 clinically normal dogs, 17 with SARDS, and 53 with neoplasia.

PROCEDURE

Thoracic radiography, ultrasonography of adrenal glands, and contrast-enhanced computed tomography of pituitary glands were performed in 15 dogs with SARDS. Western blot analysis was performed on sera of all dogs; recoverin (23 kd) and arrestin (48 kd) retinal antibodies were used as positive controls.

RESULTS

Neoplasia was not detected via diagnostic imaging in dogs with SARDS. Western blot analysis revealed bands in all dogs ranging from > 48 to < 23 kd. Prominent bands with equivalent or greater density than 1 or both positive controls at the 1:1,000 dilution, and present at the 1:3,000 dilution, were detected in 28% of clinically normal dogs, 40% of dogs with neoplasia, and 41% of dogs with SARDS. No bands in dogs with SARDS had a consistent location of immune activity, and none were detected at the 23-kd site. The area around the 48-kd site had increased immune activity in all 3 groups.

CONCLUSIONS AND CLINICAL RELEVANCE

The etiology of SARDS in dogs does not appear to be similar to cancer-associated retinopathy in humans on the basis of absence of differential antibody activity against retinal proteins. Although dogs with SARDS often have clinical signs compatible with hyperadrenocorticism, neoplasia of the adrenal glands, pituitary gland, or lungs was not detected.

Phaeochromocytoma treated by en bloc resection including the suprarenal caudal vena cava in a dog

A 10-year-old, neutered male Cairn terrier was examined after experiencing intermittent vomiting of several months' duration and sudden onset of acute depression. Abdominal ultrasound examination revealed an adrenal mass invading the suprarenal part of the caudal vena cava. The vascular invasion could not be corrected so en bloc ligation/excision of the adrenal neoplasm and the suprarenal part of the vena cava was performed. Microscopic examination identified an adrenal phaeochromocytoma. The dog recovered well and had no significant vascular or renal dysfunction at follow-up 20 months after surgery. To the authors' knowledge, this is the first report of a dog surviving long term after resection of the suprarenal caudal vena cava.

PHEOCHROMOCYTOMA IN AN AGED FEMALE AFRICAN ELEPHANT (LOXODONTA AFRICANA)

A 43 yr-old female African elephant (Loxodonta africana) collapsed acutely and died. Necropsy revealed an enlarged right adrenal medulla. Histologic appearance was typical of pheochromocytoma. Special stains and electron microscopy demonstrated chromaffin granules, suggesting that the tumor was derived from catecholamine secreting cells of the adrenal medulla, and may have been functionally secretory. Serum levels of both norepinephrine and epinephrine were elevated at time of death, supporting the functional nature of the tumor. Histologic findings of arteriolar sclerosis and smooth muscle hyperplasia suggested that the animal may have suffered from chronic systemic hypertension. Pheochromocytoma should be considered as a differential diagnosis in cases of suspected hypertension and acute death in elephants.

A case of adrenal gland dependent hyperadrenocorticism with mitotane therapy in a Yorkshire terrier dog

Hyperadrenocorticism, a disorder characterized by excessive production of cortisol by the adrenal cortex, is well-recognized in dogs. A 10-year-old, intact male, Yorkshire terrier dog was evaluated because of corneal ulceration and generalized alopecia. Diagnosis was made based on history taking, clinical signs, physical examination, and results of routine laboratory testing (complete blood count, serum biochemical analysis, and urinalysis). In addition, adrenocorticotropic hormone (ACTH) stimulation test and abdominal ultrasonography were also used to diagnose this case. The patient was diagnosed as adrenal gland neoplasia and medical therapy using the adrenocorticolytic agent, mitotane, was initiated. An ACTH stimulation test was performed after initial therapy. After successful induction was obtained, maintenance therapy with mitotane still continued.

Multiple endocrine neoplasia type I in a cat

A 13-year-old 4.6-kg (10.2-lb) neutered male domestic long hair cat was evaluated because of a history of lethargy, exercise intolerance, and ventroflexion of the cervical portion of the vertebral column. After extensive assessment at the Veterinary Teaching Hospital at Michigan State University, the clinical signs were attributed to an aldosterone-secreting tumor of the adrenal gland. Subsequently, an insulin-secreting tumor of the pancreas as well as a functional parathyroid gland adenoma were diagnosed. All 3 masses were surgically removed, and the cat made a full recovery with complete resolution of clinical signs. The syndrome of multiple endocrine neoplasia is well described in humans, and the heritability of the condition has been confirmed. In cats and other species with 1 or more endocrine neoplasms, it is important to perform thorough clinical assessments of patients to identify other endocrine organs that may also be affected concurrently with neoplastic disease.

Metastatic tumors to the adrenal glands in domestic animals

Although metastases to the adrenals are common in humans, they have not been thoroughly studied in animals. The purpose of this retrospective study was to document the types of malignant tumors that metastasize to canine, feline, equine, and bovine adrenals, and the rate at which they do so. The average rate of adrenal involvement in metastatic cancer was 112/534 (21.0%) in dogs, 12/81 (14.8%) in cats, 18/67 (26.9%) in horses, and 5/16 (31.3%) in cattle. In dogs, 26 different tumor types metastasized to the adrenals. Pulmonary, mammary, prostatic, gastric, and pancreatic carcinomas, and melanoma had the highest rates of metastasis to the adrenal glands in dogs. Hemangiosarcoma and melanoma had high rates of adrenal involvement in horses. In cats and cattle, relevant data were only available for lymphoma. Adrenal metastases usually occurred in the late stages of the disease. One dog had developed Addison's disease (hypoadrenocorticism) secondary to lymphoma. Metastatic lesions represented 126/472 (26.7%) of canine, 12/20 (60.0%) of feline, 21/80 (26.3%) of equine, and 5/9 (55.5%) of bovine adrenal neoplasms. This study shows that adrenal glands should be thoroughly examined during both clinical work-up and postmortems when disseminated neoplasia is suspected.

The stability of historical control data for common neoplasms in laboratory rats: adrenal gland (medulla), mammary gland, liver, endocrine pancreas, and pituitary gland

Time-related changes in the incidences of spontaneous neoplasms in adrenals (medulla), mamma, liver, pituitary, and (endocrine) pancreas were assessed statistically in Wistar, Sprague-Dawley, and F344 rats employed by BASF, Germany and major European contract research organizations over the last 20 years. Negative trends (7 of 80 cases) were observed for pituitary pars distalis adenomas in Sprague-Dawley males and females, for pancreas islet cell adenomas in BASF Wistar males and females, for benign adrenal pheochromocytomas in Sprague-Dawley males, for malignant pheochromocytomas in F344 males, and for mammary gland fibroadenomas in BASF Wistar females. Positive trends (13 of 80 cases) were observed for benign pheochromocytomas, mammary gland adenocarcinomas, and pancreas islet cell carcinomas in HanWistar females, for malignant pheochromocytomas and islet cell carcinomas in BASF Wistar males, for benign pheochromocytomas and islet cell adenomas in F344 males, for mammary gland fibroadenomas in Sprague-Dawley females, and for benign hepatocellular tumors in HanWistar males and females, and in BASF Wistar and Sprague-Dawley females. In 60 of 80 cases there were no statistically significant trends. These results indicate that the majority of tumor types showed no time trends and that, in each rat strain, certain tumor types are susceptible to slight positive or negative time trends. Accordingly, the validity and use of historical control data should be based on an organ- and strain-specific statistical analysis of tumor incidence over time.

Two unusual tumours in a ferret (Mustela putorius furo)

This case report describes the clinical history, diagnosis and treatment of a ferret with a tumour of the right adrenal gland and insulinomas of the pancreas. Histopathology of both lesions confirmed the diagnoses. Clinical signs of the adrenal gland tumour were a swollen vulva, overgrooming, sexual activity and pruritus. The clinical signs suggesting insulinomas were collapse of the ferret, disorientation and ptyalism. A low blood glucose level assisted the diagnosis of insulinomas. This is believed to be the first reported case of concurrent insulinomas and adrenal gland tumour in a ferret in the United Kingdom.