Kidney sparing during surgical treatment of an adrenocortical carcinoma with renal vein invasion in a cat.

A 15-year-old domestic shorthair cat was presented with gastrointestinal signs, polyuria, polydipsia, and weakness. Abdominal bruit ("whooshing" sound from turbulent blood flow) and hypertension (systolic blood pressure: 200 mmHg) were present. A left adrenal gland mass was detected with abdominal ultrasonography; a subsequent CT examination identified a mass and a thrombus in the ipsilateral renal vein. Adrenalectomy and venotomy were completed but nephrectomy was not necessary. Histological diagnosis was an adrenocortical carcinoma. There were no clinical signs at a follow-up examination 30 mo after surgery. Key clinical message: This report describes successful surgical management of feline adrenocortical carcinoma with renal vein invasion without kidney damage. This case suggests that, after correct diagnosis and in well-selected cases, surgery to remove adrenal tumors and thrombi in cats, despite renal vein invasion, can be done with excellent short- and long-term outcomes.

Sauvegarde des reins lors du traitement chirurgical d'un carcinome corticosurrénalien avec invasion des veines rénales chez un chatUn chat domestique à poil court de 15 ans a été présenté avec des signes gastro-intestinaux, une polyurie, une polydipsie et une faiblesse. Des bruits abdominaux (« sifflement ¼ provenant d'un flux sanguin turbulent) et une hypertension (pression artérielle systolique: 200 mmHg) étaient présents. Une masse de la glande surrénale gauche a été détectée à l'échographie abdominale; un examen tomodensitométrique ultérieur a identifié une masse et un thrombus dans la veine rénale ipsilatérale. La surrénalectomie et la veinotomie ont été réalisées mais la néphrectomie n'a pas été nécessaire. Le diagnostic histologique était un carcinome corticosurrénalien. Il n'y avait aucun signe clinique lors d'un examen de suivi 30 mois après l'intervention chirurgicale.Message clinique clé:Ce rapport décrit la prise en charge chirurgicale réussie du carcinome corticosurrénalien félin avec invasion des veines rénales sans lésion rénale. Ce cas suggère qu'après un diagnostic correct et dans des cas bien sélectionnés, une intervention chirurgicale visant à éliminer les tumeurs surrénales et les thrombi chez les chats, malgré l'invasion des veines rénales, peut être réalisée avec d'excellents résultats à court et à long terme.(Traduit par Dr Serge Messier).

Multiple endocrine neoplasia in a sheep: insulinoma, adrenocortical carcinoma with myxoid differentiation, and thyroid C-cell carcinoma.

An ~10-y-old male sheep had anorexia and progressive weight loss for ~1 mo. The sheep was emaciated, and 20 d later, became recumbent and lethargic, and was hypoglycemic (0.33 mmol/L; RI: 2.6-4.4 mmol/L). The sheep was euthanized because of poor prognosis, and submitted for autopsy. We found no gross lesions in the pancreas; however, histologically, focal proliferations of round-to-polygonal cells were separated by connective tissue into small nests. These proliferating cells, which had abundant eosinophilic-to-amphophilic cytoplasm and hyperchromatic nuclei, were immunopositive for insulin and negative for glucagon and somatostatin; the lesion was diagnosed as an insulinoma. Insulinoma has not been reported previously in sheep, to our knowledge. In addition, autopsy and histologic examination revealed the presence of an adrenocortical carcinoma with myxoid differentiation and a thyroid C-cell carcinoma. Our case indicates that multiple endocrine neoplasms can occur in sheep, as in other animal species.

18F-FDG PET/CT image findings of a dog with adrenocortical carcinoma.

BACKGROUND: In human medicine, 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET) has been used to differentiate between benign and malignant adrenal tumors and to identify metastases. However, canine adrenocortical carcinomas identified by 18F-FDG PET/computed tomography (CT) have not been reported. CASE PRESENTATION: A 13-year-old, castrated male, Cocker Spaniel dog with severe systolic hypertension exhibited an adrenal mass approximately 3.6 cm in diameter on ultrasonography. There was no evidence of pulmonary metastasis or vascular invasion on thoracic radiography and abdominal ultrasonography, respectively. 18F-FDG PET/CT was performed to identify the characteristics of the adrenal mass and the state of metastasis. One hour after injection of 5.46 MBq/kg 18F-FDG intravenously, the peripheral region of the adrenal mass visually revealed an increased 18F-FDG uptake, which was higher than that of the liver, and the central region of the mass exhibited necrosis. The maximal standardized uptake value (SUV) of the adrenal mass was 3.24; and relative SUV, calculated by dividing the maximal SUV of the adrenal tumor by the mean SUV of the normal liver, was 5.23. Adrenocortical carcinoma was tentatively diagnosed and surgical adrenalectomy was performed. Histopathologic examination of the resected adrenal mass revealed the characteristics of an adrenocortical carcinoma. After adrenalectomy, systolic blood pressure reduced to below 150 mmHg without any medication. CONCLUSION: This is the first case report of 18F-FDG PET/CT findings in a dog with suspected adrenocortical carcinoma and may provide valuable diagnostic information for adrenocortical carcinoma in dogs.

Perioperative morbidity and mortality in dogs with invasive adrenal neoplasms treated by adrenalectomy and cavotomy.

OBJECTIVE: To report the morbidity and mortality associated with adrenalectomy with cavotomy for resection of invasive adrenal neoplasms in dogs and evaluate risk factors for perioperative outcomes. STUDY DESIGN: Retrospective study. ANIMALS: Forty-five client-owned dogs. METHODS: Dogs that underwent open adrenalectomy with cavotomy for resection of adrenal masses with tumor thrombus extending into the vena cava were included. Clinicopathologic data were harvested from medical records. Selected clinical, imaging, and operative variables were statistically evaluated as risk factors for packed red blood cell transfusion, nephrectomy, perioperative death, and overall survival. RESULTS: Thirty-six of 45 masses were pheochromocytomas, 7 were adrenocortical carcinomas, and 2 were unknown type. Caval thrombus terminated prehepatically in 21 of 45 dogs and extended beyond the porta hepatis but terminated prediaphragmatically (intrahepatic prediaphragmatic location) in 15 dogs and thrombi extended postdiaphragmatically in 5 dogs. Thirty-four (76%) dogs were discharged from the hospital, and 11 (24%) dogs died or were euthanized prior to discharge. Median overall survival time for all 45 dogs was 547 days (95%CI 146-710). Bodyweight, tumor type, and size and extent of caval thrombus did not affect survival to discharge, but postdiaphragmatic (rather than prediaphragmatic) thrombus termination was associated with a greater risk of death. CONCLUSION: Long-term survival was common in dogs that survived the perioperative period. Postdiaphragmatic thrombus extension affected the prognosis for overall survival. CLINICAL SIGNIFICANCE: Findings of this study help to stratify operative risk in dogs with adrenal neoplasia and caval invasion.

Aldosterone-producing adrenocortical carcinoma with myxoid differentiation in a cat.

A 10-year-old male neutered Persian cat was presented with an abdominal mass and history of weakness. Blood smear examination found marked elliptocytosis, and serum biochemical analysis revealed hypokalemia, hypochloremia, increased creatine kinase activity, and a high aldosterone concentration. Cytologic examination of the mass revealed neoplastic endocrine cells with moderate criteria of malignancy, favoring adrenocortical neoplasia. The adrenal mass was surgically excised and histologically characterized by lobules of mildly pleomorphic, polygonal neoplastic cells with moderate to abundant, occasionally granular, eosinophilic cytoplasm. Lobules were separated by fine fibrovascular trabeculae, and numerous cystic cavities containing amorphous eosinophilic material that stained positive with Alcian blue and periodic acid-Schiff were seen. Neoplastic cells were multifocally positive for cytochrome P450 aldosterone synthase. Based on clinicopathologic and immunohistochemical findings the present case was diagnosed as an aldosterone-producing adrenocortical carcinoma with myxoid differentiation. While this entity has not been reported in cats, myxoid differentiation of adrenocortical carcinomas has been found in other species and can pose a major diagnostic challenge on microscopic examination.

Phrenicoabdominal venotomy for tumor thrombectomy in dogs with adrenal neoplasia and suspected vena caval invasion.

OBJECTIVE: To describe a technique for tumor thrombectomy by phrenicoabdominal venotomy in dogs with adrenal neoplasia and suspected caval invasion and to report complications and outcomes associated with the procedure. STUDY DESIGN: Retrospective case series. ANIMALS: Eight client-owned dogs with invasive adrenal tumors. METHODS: Medical records of dogs diagnosed with adrenal tumors with extension of thrombus into the phrenicoabdominal vein (PAV) and vena cava were reviewed. Cases where phrenicoabdominal venotomy without cavotomy for thrombus resection was performed were included. Data collected from the medical records included signalment, clinical signs, physical examination findings, diagnostic imaging results, preoperative laboratory testing, surgical technique, surgical and postoperative complications and outcome. RESULTS: Phrenicoabdominal venotomy was successful in removal of vena caval thrombosis in 7 of 8 dogs. In one case, an attempt was made to remove a large vena caval thrombus through a distended PAV resulting in fragmentation of the thrombus and the need to extend the incision into the vena cava. In all dogs, complete removal of tumor thrombus was achieved. Two dogs died in the perioperative period, one from cardiopulmonary arrest and a second from bronchopneumonia and pancreatitis. The remaining 6 dogs were discharged from the hospital. CONCLUSION: Thrombectomy through a phrenicoabdominal venotomy may obviate the need for a cavotomy in a subset of dogs with invasive adrenal neoplasia.

Clinical and pathological features and outcome of bilateral incidental adrenocortical carcinomas in a dog.

A 9-year-old, spayed female Chihuahua was presented with a 1-week history of lethargy and anorexia. Abdominal ultrasonography and computed tomography found bilateral adrenal masses without metastasis. Serum cortisol levels that were sampled before and after an adrenocorticotropic hormone stimulation test were within reference ranges. Lethargy and anorexia completely resolved after short-term fluid therapy; the clinical signs did not occur for approximately 8 months until her sudden death. A postmortem examination revealed bilateral adrenocortical carcinomas and liver metastasis. Primary adrenocortical carcinomas developed in the dog met the definition of bilateral incidental adrenal gland masses (IAGMs). This is the first case report to demonstrate based on histological identification that adrenocortical carcinomas cause bilateral IAGMs in dogs.

Perioperative Management and Outcome of Bilateral Adrenalectomy in 9 Dogs.

OBJECTIVE: To report perioperative care, postoperative management, and long-term outcomes in dogs undergoing bilateral adrenalectomy. STUDY DESIGN: Retrospective case series. ANIMALS: Dogs undergoing bilateral adrenalectomy from 2008 to 2013 (n=9). METHODS: Data retrieved from the record, when available, included signalment, preoperative clinical signs, laboratory data, diagnostic imaging, blood pressure measurement, preoperative treatment for adrenal gland disease, intraoperative procedures, treatments and complications, postoperative treatment and diagnostics during hospitalization, diagnostics and management following discharge, histopathologic diagnosis, and survival. RESULTS: Seven dogs underwent concurrent bilateral adrenalectomy and 2 dogs had staged adrenalectomy. Surgery was uncomplicated in most cases. All dogs received IV dexamethasone SP intraoperatively. Eight dogs received intramuscular desoxycorticosterone pivalate intraoperatively. Histopathology revealed adrenocortical adenoma (7 dogs), adrenocortical carcinoma (4), pheochromocytoma (6), and adrenocortical atrophy (1). One dog died perioperatively and the remainder died due to unrelated causes. Postoperative management of hypoadrenocorticism included oral prednisone and intramuscular desoxycorticosterone pivalate (6 dogs), oral prednisone and fludrocortisone (1), and oral fludrocortisone alone (1). The median survival time in dogs surviving to hospital discharge was 525 days (range 67-966 days). No dogs developed metastatic disease or died due to signs of hypoadrenocorticism. CONCLUSION: Based on the cases reported here, the perioperative mortality in dogs undergoing bilateral adrenalectomy may be lower than previously reported. Management of postoperative hypoadrenocorticism is both achievable and straightforward.

Preoperative Differential Diagnosis of Canine Adrenal Tumors Using Triple-Phase Helical Computed Tomography.

OBJECTIVE: To characterize the computed tomography (CT) findings for canine adrenal tumors, including cortical adenoma, cortical adenocarcinoma, and pheochromocytoma, and to evaluate the feasibility and usefulness of preoperative triple-phase helical CT for differentiation of tumor types and surgical planning. STUDY DESIGN: Retrospective study. ANIMALS: Dogs with adrenal tumors (n=36). METHODS: All dogs underwent triple-phase helical CT, followed by adrenalectomy and histopathological diagnosis of the resected mass. Precontrast images, arterial, venous, and delayed phase images were obtained. In all cases, morphological characteristics and CT values and calculations, including the percentage enhancement washout ratio, relative percentage washout, enhancement washin, and enhancement washout, were analyzed and compared among the tumor types. RESULTS: Of the 36 dogs with adrenal masses, cortical adenocarcinoma was most commonly diagnosed (16 dogs), followed by pheochromocytoma (13 dogs), and cortical adenoma (7 dogs). The precontrast minimum CT value and enhancement washout between venous and delayed phases in the cortical adenoma were significantly higher than those in the cortical adenocarcinoma. The maximum CT values of the precontrast image and arterial and venous phases, the enhancement washin and washouts, percentage enhancement washout ratio, and relative percentage washout in the pheochromocytomas were significantly higher than those in cortical adenocarcinoma. CONCLUSION: The differential diagnosis of canine adrenal tumors was feasible based on triple-phase CT findings, including morphological features, CT values, and intratumoral contrast attenuation. Preoperative diagnosis using triple-phase helical CT may be useful for surgical planning in dogs with adrenal tumors.

Intercostal approach for right adrenalectomy in dogs.

OBJECTIVE: To describe an intercostal (IC) approach to the right adrenal (RA) gland in dogs. STUDY DESIGN: Cadaveric study and case series. ANIMALS: Dogs with right adrenal (RA) tumors (n = 11) and normal canine cadavers (6). METHODS: Cadavers had an IC (n = 3) or paracostal (3) approach to the RA. The relative spatial position of the RA to the incision was evaluated. Medical records (June 2007-December 2012) of dogs that had an IC approach to the RA were reviewed. Perioperative data were recorded and described. RESULTS: In cadavers, the RA was closer to the cranial aspect of the surgical incision after an IC approach compared with a paracostal approach. The IC approach for right adrenalectomy was successfully performed in 11 dogs (6 adrenocortical carcinomas, 4 pheochromocytomas, and 1 osteosarcoma) with a mean anesthesia duration of 242 minutes and mean surgical of 144 minutes. Dogs had vascular invasion into the phrenicoabdominal vein (n = 11) and caudal vena cava (6). There were no significant intra- or postoperative complications. One dog was euthanatized intraoperatively. Median survival time for all dogs was 786 days. CONCLUSIONS: The IC approach for right adrenalectomy offers superior exposure of the RA compared with a paracostal approach.

Expression of angiogenesis-related genes in canine cortisol-secreting adrenocortical tumors.

The aim of this study was to evaluate the expression of angiogenesis-related genes in canine cortisol-secreting adrenocortical tumors (ATs). Quantitative RT-PCR analysis revealed mRNA encoding for vascular endothelial growth factor, vascular endothelial growth factor receptors 1 and 2, angiopoietin 1 and 2 (ANGPT1 and ANGPT2), the splice variant ANGPT2443, the ANGPT-receptor Tie2, and basic fibroblast growth factor in 38 canine cortisol-secreting ATs (26 carcinomas and 12 adenomas) and 15 normal adrenals. The relative expression of both ANGPT2 and ANGPT2443 was higher in adenomas (P = 0.020 for ANGPT2 and P = 0.002 for ANGPT2443) and carcinomas (P = 0.003 for ANGPT2 and P < 0.001 for ANGPT2443) compared with normal adrenals, and this enhanced expression was also detected with Western blot analysis. Immunohistochemistry indicated expression of ANGPT2 protein in AT cells and in vascular endothelial cells of carcinomas, whereas Tie2 was mainly present in the tumor vascular endothelial cells. The ANGPT2-to-ANGTPT1 ratio, a marker for a proangiogenic state, was higher in both adenomas (P = 0.020) and carcinomas (P = 0.043). With the use of the human H295R cortisol-producing adrenocortical carcinoma cell line, we were able to demonstrate that the ANGPT2 expression was stimulated by cyclic adenosine monophosphate and progesterone but not by cortisol. In conclusion, canine cortisol-secreting ATs have enhanced ANGPT2 expression with a concomitant shift toward a proangiogenic state. On the basis of this information, treatment modalities may be developed that interfere with ANGPT2 expression, including inhibition of the cyclic adenosine monophosphate/protein kinase A pathway, or of the effect of ANGPT2, by using specific ANGPT2 inhibitors.

Treatment of aldosterone-secreting adrenocortical tumors in cats by unilateral adrenalectomy: 10 cases (2002-2012).

BACKGROUND: Primary hyperaldosteronism (PHA) in cats occurs as a consequence of excessive hormone production by an adrenocortical tumor. Median survival time, association between tumor type and prognosis, and the likelihood that cats require continued medical therapy after surgery have not been systematically evaluated. OBJECTIVES: To determine the median survival time of cats with PHA treated by unilateral adrenalectomy. To examine if tumor type, anesthesia time, or tumor location (left or right side) affect survival and if affected cats require continued postoperative treatment for persistent hypertension or hypokalemia. ANIMALS: Ten client-owned cats. METHODS: Retrospective study. Cats were diagnosed with PHA based on clinical signs, increased plasma aldosterone concentration, and advanced imaging. Cats underwent unilateral adrenalectomy. Survival time (days alive after surgery) was determined for each cat. Factors affecting median survival time were investigated, including histopathology, anesthesia time, and location (side) of the tumor. RESULTS: Eight of 10 cats survived to discharge from the hospital post adrenalectomy. Overall median survival was 1,297 days (range 2-1,582 days). The only significant factor affecting median survival time was anesthesia time >4 hours. Tumor type and location (side) did not significantly affect median survival time. No cats required continued medical treatment for PHA. CONCLUSIONS AND CLINICAL IMPORTANCE: Although PHA in cats is still considered an uncommon condition, it should be considered in middle to older aged cats with hypokalemic polymyopathy and systemic hypertension. Surgical correction by unilateral adrenalectomy is a viable approach to definitive treatment of PHA with no need for continued medical management.

Use of a GnRH vaccine, GonaCon, for prevention and treatment of adrenocortical disease (ACD) in domestic ferrets.

Adrenocortical disease (ACD) is a common problem in surgically sterilized, middle-aged to old ferrets (Mustela putorius furo). The adrenal tissues of these ferrets develop hyperplasia, adenomas, or adenocarcinomas, which produce steroid hormones including estradiol, 17-hydroxyprogesterone, and androstenedione. Major clinical signs attributable to overproduction of these hormones are alopecia (hair loss) in both sexes and a swollen vulva in females. Pruritus, muscle atrophy, hind limb weakness, and sexual activity or aggression are also observed in both sexes. Males can develop prostatic cysts, prostatitis, and urethral obstruction. ACD is thought to be linked to continuous and increased LH secretion, due to lack of gonadal hormone feedback in neutered ferrets. This continuous elevated LH acts on adrenal cortex LH receptors, resulting in adrenal hyperplasia or adrenal tumor. This study investigated whether the immunocontraceptive vaccine GonaCon, a GnRH vaccine developed to reduce the fertility of wildlife species and the spread of disease, could prevent or delay onset of ACD and treat alopecia in ferrets with existing ACD. Results showed that GonaCon provided relief from ACD by causing production of antibodies to GnRH, probably suppressing production and/or release of LH. Treatment caused many ACD symptoms to disappear, allowing the ferrets to return to a normal life. The study also found that the probability of developing ACD was significantly reduced in ferrets treated with GonaCon when young (1-3 years old) compared to untreated control animals. GonaCon caused injection site reaction in some animals when administered as an intramuscular injection but caused few side effects when administered subcutaneously. Both intramuscular and subcutaneous vaccination resulted in similar levels of GnRH antibody titers. Subcutaneous vaccination with GonaCon is thus recommended to prevent the onset of ACD and as a possible treatment for ACD-signs in domestic ferrets.

Evaluation of risk factors for outcome associated with adrenal gland tumors with or without invasion of the caudal vena cava and treated via adrenalectomy in dogs: 86 cases (1993-2009).

OBJECTIVE: To evaluate risk factors for outcome for dogs with adrenal gland tumors with or without invasion of the caudal vena cava treated via adrenalectomy. DESIGN: Retrospective study. ANIMALS: 86 dogs that underwent adrenalectomy for treatment of adrenal gland tumors. PROCEDURES: Medical records of dogs that underwent adrenalectomy for treatment of an adrenal gland tumor from 1993 to 2009 were reviewed; data collected including signalment, clinical signs, diagnostic test findings, treatments prior to surgery, findings at surgery including additional procedures performed and extent of caudal vena caval invasion (local invasion [caudal to the hepatic portion of the vena cava] or extensive invasion [cranial to the hepatic portion of the vena cava]), procedures performed during surgery, histopathologic diagnosis, perioperative complications, follow-up data, and necropsy findings. RESULTS: Of the 86 dogs, 14 had adenomas, 45 had adrenocortical carcinomas, and 27 had pheochromocytomas. Fourteen dogs had invasion of the caudal vena cava; of these tumors, 7 were locally invasive and 7 were extensively invasive. Risk factors for poor short-term survival (death within 14 days following surgery) were vena caval invasion, extent of invasion, pheochromocytoma, intraoperative transfusion, and postoperative factors including disseminated intravascular coagulation, pancreatitis, hypotension, hypoxemia, and renal failure. Multivariate analysis of risk factors for poor short-term survival revealed that extensive invasion was the most important factor. Regardless of extent of invasion or tumor type, long-term survival was possible. CONCLUSIONS AND CLINICAL RELEVANCE: Invasion of the caudal vena cava, particularly tumor thrombus extension beyond the hepatic hilus, was associated with a higher postoperative mortality rate, but did not affect long-term prognosis in dogs undergoing adrenalectomy because of an adrenal gland tumor.

Oncocytic adrenocortical carcinoma in a putty-nosed monkey (Cercopithecus nictitans) with hyperadrenocorticism.

Oncocytic adrenocortical tumours are rare in man and have never been described in non-human primates. An oncocytic adrenocortical carcinoma was identified in an 18-year-old female putty-nosed monkey (Cercopithecus nictitans) with hyperadrenocorticism and invasive aspergillosis. Microscopically, the tumour consisted of large cells with abundant eosinophilic, granular cytoplasm containing numerous mitochondria as identified by electron microscopy. Tumour cells had large nuclei with occasional intranuclear cytoplasmic pseudoinclusions. Immunohistochemically, tumour cells expressed vimentin, synaptophysin and neuron-specific enolase, while they were negative for cytokeratin, chromogranin-A, melan-A and S100.

Adrenal cortex carcinomas with distant metastases in beef cattle at slaughter.

Ten cases of adrenal cortex carcinomas with distant metastases were collected as subclinical lesions at slaughter of approximately 14,000 adult cattle. The primary lesion in the adrenal gland and the distant metastases, to either the lung or liver, were characterized by light microscopy and immunohistochemistry. Carcinomas were usually detected by noting metastases in the lungs as polypoid, soft, red or red and yellow masses. All adrenal tumours were unilateral and none were seen in bulls. In six of 10 carcinomas there was gross evidence of invasion of the vena cava via the adrenal vein. Normal bovine adrenal cortex labelled positively with S100, calretinin, α inhibin and melan-A; however, adenomas and seven of 10 carcinomas were labelled best by melan-A and α inhibin. Three carcinomas, grossly identical to the other seven, had numerous calcific granules and a slightly different microscopical appearance. In addition to melan-A and α-inhibin, these variant carcinomas labelled with S100. This variant may be derived from a different layer of the adrenal cortex. Because of the similarity of the bovine and human adrenal cortices, cultures of spontaneously arising bovine adrenal tumours may be a useful resource for study of human neoplasia.

Histologic and immunohistochemical classification of 41 bovine adrenal gland neoplasms.

Tumors of the adrenal glands are among the most frequent tumors in cattle; however, few studies have been conducted to describe their characteristics. The aim of this study was to classify 41 bovine adrenal neoplasms from 40 animals based on macroscopic and histologic examination, including electron microscopy and immunohistochemistry for melan A, synaptophysin, chromogranin A, vimentin, pan-cytokeratin, 2',3'-cyclic nucleotide-3'-phosphohydrolase (CNPase), and Ki-67. The tumors were classified as 23 adrenocortical adenomas, 12 adrenocortical carcinomas, 2 schwannomas, 2 pheochromocytomas (1 malignant), and 1 ganglioneuroma. Five histologic features were characteristic of metastasizing adrenocortical tumors: invasion of the capsule, vascular invasion, diffuse growth pattern, spindle-cell morphology, and nuclear pleomorphism. Adrenocortical tumors with at least 3 of these features were classified as malignant. Immunohistochemically, adrenocortical tumors expressed melan A (16/19), vimentin (14/26), cytokeratin (11/26), and chromogranin A (9/27), whereas pheochromocytomas expressed chromogranin A (2/2), synaptophysin (2/2), and vimentin (1/2). Both schwannomas expressed CNPase. An immunohistochemistry panel consisting of antibodies against melan A, synaptophysin, and CNPase was considered most useful to classify bovine adrenal tumors. However, the distinction between benign and malignant adrenocortical tumors was based on histologic features as in human medicine.

Functioning unilateral adrenocortical carcinoma in a dog.

An 11-year-old, 24-kg, intact female Siberian husky dog in anestrus had a 2-month history of polyuria and polydipsia. The dog had signs of mineralocorticoid excess such as hypertension and hypokalemia refractory to potassium supplementation. Abdominal ultrasound revealed an irregular mass in the left adrenal gland. The ACTH stimulation test for aldosterone concentration did not reveal hyperaldosteronism. Unilateral adrenalectomy was performed and histopathology identified adrenal cortical carcinoma. All clinical signs of mineralocorticoid excess ceased after surgery.

Adrenocortical carcinoma in a dog with incomplete excision managed long-term with metastasectomy alone.

A 10 yr old bichon frise presented with a 3 mo history of polyuria, polydipsia, and hind limb weakness. Serum biochemistry revealed persistent hypokalemia. A left adrenal gland mass with right adrenal atrophy was detected ultrasonographically. Basal serum cortisol concentration was at the low end of normal (30 nmol/L; reference range, 30-140 nmol/L) and adrenocorticotropic hormone (ACTH)-stimulated cortisol concentration was low (199 nmol/L; reference range, 220-470 nmol/L). Basal serum 17-α-OH progesterone concentration was also low (0.03 ng/mL; reference range, 0.06-0.30 ng/mL), but the aldosterone concentration 2 hr after the ACTH stimulation was elevated (> 3,000 pmol/L; reference range, 197-2,103 pmol/L). A left adrenalectomy and nephrectomy were performed. Histopathology revealed an adrenocortical zona glomerulosa carcinoma. Surgical excision was considered incomplete; however, clinical signs resolved. Two years later, basal and ACTH-stimulated aldosterone concentrations were elevated. Computed tomography demonstrated a mass effect in the liver. The left lateral and left medial hepatic lobes were removed. Histopathology confirmed metastatic endocrine carcinoma. The patient was stable 1,353 days postsurgically (when this report was prepared). This is the first case report of a metastatic adrenal carcinoma that was successfully managed surgically for > 3 yr.