A case report of feline pituitary carcinoma with hypercortisolism

Feline Pituitary Adenomas: Correlation of Histologic and Immunohistochemical Characteristics With Clinical Findings and Case Outcome

Pituitary glands from 141 feline autopsy cases were reviewed histologically. Adenoma and hyperplasia were the most common lesions at 13 cases each. Pituitary adenoma was more likely than hyperplasia to be associated with clinical evidence of endocrinopathy or an intracranial mass (P < .001). A histochemical and immunohistochemical panel was applied to 44 autopsy- or hypophysectomy-derived pituitary adenomas in 43 cats from 2 diagnostic laboratories. Adenomas were differentiated from hyperplasia by the presence of disrupted reticulin fibers. One cat had a double (somatotroph and melanotroph) adenoma. Twenty somatotroph adenomas consisted of periodic acid-Schiff (PAS)-negative acidophils that expressed growth hormone; 16/20 had hypersomatotropism; 17/20 had diabetes mellitus. Eleven melanotroph adenomas consisted of PAS-positive basophils or chromophobes that expressed melanocyte-stimulating and adrenocorticotrophic hormones; 5/11 had hypercortisolism; 6/11 had diabetes mellitus. Eleven gonadotroph adenomas consisted of PAS-negative chromophobes that expressed follicle-stimulating and/or luteinizing hormones. Two thyrotroph adenomas consisted of PAS-negative basophils or chromophobes that expressed thyroid-stimulating hormone. Pituitary-dependent disease was not recognized in cats with gonadotroph or thyrotroph adenomas. The Ki-67 proliferation index in hypophysectomy specimens was lower in somatotroph than in melanotroph adenomas. Fourteen cats with hypophysectomy-treated somatotroph or melanotroph adenoma had an 899-day median survival time versus 173 days in 17 nonsurgical cases. After adjusting for age, adenoma size and type, hypophysectomized cats had an overall better survival time than nonsurgical cases (P = .029). The study results underscore the value of hypophysectomy and trophic hormone immunohistochemistry in the treatment and classification of feline pituitary adenomas.

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

PRACTICAL RELEVANCE

Abdominal ultrasound plays a vital role in the diagnostic work-up of many cats presenting to general and specialist practitioners. Ultrasound examination of the adrenal glands can provide important information pertaining to several conditions including hyperaldosteronism and hyperadrenocorticism.

CLINICAL CHALLENGES

Despite ultrasonography being a commonly used modality, many practitioners are not comfortable performing an ultrasound examination or interpreting the resulting images. Even for the experienced ultrasonographer, differentiating between incidental findings, such as adrenal mineralisation, and clinically significant pathological changes can be challenging.

AIM

This review, part of an occasional series on feline abdominal ultrasonography, discusses the ultrasonographic examination of the normal and diseased adrenal glands. Aimed at general practitioners who wish to improve their knowledge of and confidence in feline abdominal ultrasound, this review is accompanied by high-resolution images and videos available online as supplementary material.

EQUIPMENT

Ultrasound facilities are readily available to most practitioners, although the use of ultrasonography as a diagnostic tool is highly dependent on operator experience.

EVIDENCE BASE

Information provided in this article is drawn from the published literature and the author's own clinical experience.

Persistent Bilateral Mydriasis Associated With a Pituitary Adenoma in a Horse

Severe bilateral mydriasis and bilaterally decreased vision were observed in a 23-year-old crossbred warmblood gelding with a history of pituitary pars intermedia dysfunction. Ten years after the onset of clinical signs, it was killed humanely because of worsening of clinical signs and loss of therapeutic responsiveness. Postmortem examination of the head was performed to confirm the suspected pituitary neoplasm and to investigate secondary oculomotor lesions. Pathomorphologic examination revealed an expansile space-occupying pituitary adenoma and degenerative changes in the preganglionic oculomotor nerve, ciliary ganglion, and optic chiasm. The ocular clinical findings share features of a cavernous sinus syndrome.

Pathological Findings in the Pituitary Glands of Dogs and Cats

With the exception of classic functional adenomas in dogs and horses, pituitary lesions are infrequently described in the veterinary literature. Approximately 10% of pituitary glands from asymptomatic humans contain abnormalities, but the equivalent proportion in small animals is unknown. Pituitary glands from 136 dogs and 65 cats collected during routine necropsies were examined to determine the prevalence of pituitary lesions and their histopathological diagnosis. Lesions were characterized in sections stained with hematoxylin and eosin, periodic acid-Schiff (PAS), Gordon and Sweet’s and reticulin stains, and immunohistochemistry for adrenocorticotropic hormone (ACTH), growth hormone, melanocyte stimulating hormone–α, and prolactin. Pituitary abnormalities were identified in 36 of 136 (26.4%) dogs and 10 of 65 (15.3%) cats. Cystic changes were the most common lesion, occurring in 18 (13.2%) dogs and 8 (12.3%) cats. Pituitary neoplasia was detected in 14.1% (12/85) of middle-aged and old dogs; 1 (1.5%) cat had pituitary nodular hyperplasia. PAS and reticulin stains helped differentiate ACTH-immunoreactive adenomas from hyperplastic nodules: adenomas contained PAS-positive intracytoplasmic granules and loss of the normal reticulin network. One dog had a pituitary carcinoma with infiltration into the thalamus. Other pituitary abnormalities included secondary metastases (2 dogs) and hypophysitis (4 dogs, 1 cat). In most cases, the lesion appeared to be subclinical and could be considered incidental, whereas clinical manifestations were apparent in only 4 dogs (2.9%) and none of the cats with pituitary lesions. Pituitary abnormalities are common in dogs and cats, and their clinical relevance requires further investigation.

Comparative occurrence of diabetes in canine, feline, and few wild animals and their association with pancreatic diseases and ketoacidosis with therapeutic approach

Diabetes mellitus (DM) is a chronic metabolic disorder in which blood glucose level raises that can result in severe complications. However, the incidence increased mostly by obesity, pregnancy, persistent corpus luteum, and diestrus phase in humans and animals. This review has focused on addressing the possible understanding and pathogenesis of spontaneous DM in canine, feline, and few wild animals. Furthermore, pancreatic associated disorders, diabetic ketoacidosis, hormonal and drug interaction with diabetes, and herbal remedies associated with DM are elucidated. Bibliographic search for the present review was done using PubMed, Scopus, and Google Scholar for articles on concurrent DM in small and wild animals. Persistent corpus luteal and pseudopregnancy in female dogs generate gestational DM (GDM). GDM can also be caused by extensive use of drugs/hormones such as glucocorticosteroids. Although many similarities are present between diabetic cats and diabetic humans which present islet amyloidosis, there was a progressive loss of β- and α-cells and the normal number of δ-cells. The most prominent similarity is the occurrence of islet amyloidosis in all cases of diabetic cat and over 90% of human non-insulin dependent DM Type-2. Acute pancreatic necrosis (APN) occurs due to predisposing factors such as insulin antagonism, insulin resistance, alteration in glucose tolerance, obesity, hyperadrenocorticism, and persistent usage of glucocorticoids, as these play a vital role in the progression of APN. To manage such conditions, it is important to deal with the etiological agent, risk factors, diagnosis of diabetes, and hormonal and drug interaction along with its termination with suitable therapy (herbal) protocols. It should be noted that the protocols used for the diagnosis and treatment of human DM are not appropriate for animals. Further investigations regarding diabetic conditions of pets and wild animals are required, which will benefit the health status of all animals health worldwide.

Fluorescein sodium-guided resection of intracranial lesions in 22 dogs

OBJECTIVE

To evaluate the safety of an intraoperative fluorescein sodium (FS) injection and elucidate the relationships between the MRI findings, pathological diagnoses, and intraoperative staining characteristics of intracranial lesions in 22 dogs.

STUDY DESIGN

Prospective case series.

ANIMALS

Twenty-two dogs with intracranial lesions.

METHODS

FS was intravenously administered to 22 dogs undergoing craniotomy for suspected intracranial tumors to evaluate perioperative and postoperative adverse effects. The intensities and patterns of gadolinium (Gd) enhancement on preoperative magnetic resonance imaging and intraoperative FS staining were graded, and their relationship was evaluated. Intraoperative FS staining characteristics and pathological diagnoses were compared.

RESULTS

The only adverse effect noted was repetitive vomiting in 2 dogs. The intensities and patterns between preoperative Gd enhancement and intraoperative FS staining appeared to agree. High-grade glioma and histiocytic sarcoma had more intense FS staining. Lesions with strong Gd enhancement, including meningiomas and choroid plexus tumors, also had intense FS staining.

CONCLUSION

The intraoperative use of FS is a simple and safe technique to guide the resection of intracranial lesions in dogs. The findings on Gd enhancement, FS staining, and histopathology appeared to agree but require validation in a larger set of cases.

CLINICAL SIGNIFICANCE

The intraoperative use of FS may improve the prognosis of dogs with brain tumors by guiding the resection of lesions.

Peculiarities of feline hyperadrenocorticism: Update on diagnosis and treatment

Practical relevance: Hyperadrenocorticism (HAC) is a relatively uncommon endocrinopathy of older cats, with a mean age at diagnosis of 10 years. In addition to pituitary-dependent and adrenal-dependent hypercortisolism, clinical signs of HAC can result from adrenal sex steroid-producing tumours. Clinical challenges: While HAC in cats has many similarities to canine HAC, there are key differences in presentation, diagnosis and response to therapy. Most, but not all, cats with HAC have concurrent diabetes mellitus, which is often insulin resistant. Up to a third of cats with HAC have extreme skin fragility and are at high risk of debilitating iatrogenic skin tears during diagnostic or therapeutic interventions. Infections of the skin and nail beds, and urinary, respiratory and gastrointestinal tract, secondary to cortisol-induced immune suppression, are also common. Cats respond differently to dogs to adrenal function tests including adrenocorticotropic hormone (ACTH) stimulation and dexamethasone suppression tests; a 10-fold higher dose of dexamethasone is recommended in cats to screen for HAC. Curative treatment options include adrenalectomy or transsphenoidal hypophysectomy. Radiation or medical treatment may improve clinical signs. The response to mitotane therapy is poor. While trilostane is the medical treatment of choice based on retrospective studies, investigations into the pharmacokinetics of this drug in cats are lacking. Global importance: Feline HAC occurs worldwide and is not associated with any purebreed predisposition. Although uncommon, adrenal sex steroid-producing tumours have a higher prevalence in cats than in dogs. Evidence base: The information in this review is drawn from over 180 reported cases of feline HAC. Reports investigating clinical presentation, clinicopathological findings and treatment outcomes are observational, retrospective multiple case series (EBM grade III) or single case reports (EBM grade IV). While most endocrine testing studies for diagnosis are cohort controlled analytical studies (EBM grade III), prospective, randomised, placebo-controlled studies have been performed (EBM grade I).

Hydrocortisone therapy in a cat with vasopressor-refractory septic shock and suspected critical illness-related corticosteroid insufficiency

A 27‐month‐old female cat was presented with septic peritonitis secondary to a ruptured pyometra and subsequent pyothorax. Vasopressor‐refractory septic shock led to a suspicion of critical illness‐related corticosteroid insufficiency, successfully treated with intravenous hydrocortisone. Previous megestrol acetate administration may have played a role in the development of adrenocortical dysfunction.