Cyclic estrous-like behavior in a spayed cat associated with excessive sex-hormone production by an adrenocortical carcinoma

Behavior Changes Associated with Metabolic Disease of Dogs and Cats

Like many physical disorders, the clinical signs associated with metabolic diseases affecting thyroid, adrenal, and pancreatic function are reflective of nonspecific changes in behavior. Additionally, patients who have underlying disorders associated with fear, anxiety, stress, conflict, and/or panic may be under treatment with medications that alter basal thyroid, glucose, and cortisol levels. Through reinforcement and punishment of behaviors associated with clinical signs caused by organic or iatrogenic endocrine disease, behaviors can be perpetuated and become persistent patterns. Screening all patients presenting with a primary behavior complaint or those with behavioral clinical signs of endocrine diseases is essential. Alleviating stress immediately while working up or treating metabolic disease reduces suffering and may stave off the adoption of behavior patterns more permanently.

Case report: Androgen-secreting adrenocortical tumors in eight cats

Urine marking, aggression, and other behavioral concerns are common reasons for cat owners to seek veterinary care. Empiric treatment for lower urinary tract disease or primary behavior disorders are commonly pursued, especially in those cases with normal routine laboratory evaluations. Herein, we report the clinicopathologic findings in eight sexually altered cats that were diagnosed with androgen-secreting adrenocortical tumors. Nearly all cats (n = 7) initially were evaluated for inappropriate urination and pungent urine, with additional behavioral concerns including aggression (n = 3) and excess vocalization (n = 4) commonly reported. Penile barbs (n = 5) were identified in all five male cats, and an enlarged clitoris was observed in one female cat. Testing of serum androgen concentrations revealed abnormally high androstenedione (n = 1) or testosterone (n = 7) concentrations. In the five cases with available adrenal tissue, histopathologic evaluation identified either an adrenocortical adenoma (n = 3) or adrenocortical carcinoma (n = 2). Hormonal abnormalities resolved and clinical signs improved in the four cats that underwent surgical adrenalectomy, with each of these cats surviving >1 year. However, clinical signs were minimally impacted with medical treatments, including one cat in which trilostane treatment failed to improve clinical signs or testosterone concentrations. This collection of cases underscores the importance of a detailed physical examination as well as the consideration of endocrine disturbances in cats undergoing evaluation for inappropriate urination or aggression. Furthermore, this report adds to the growing body of evidence that sex-hormone secreting adrenal tumors in cats may be an under-recognized syndrome.

Serum antimüllerian hormone concentrations in female cats. Relation with ovarian remnant syndrome, ovarian cysts and gonadectomy status

The aim of this study was to reveal (1) the determination of the serum antimüllerian hormone concentrations in cats with ovarian remnant syndrome and ovarian cyst, (2) the effectiveness of the serum antimüllerian hormone concentrations in detecting gonadectomy status, and (3) ovarian expression of the antimüllerian hormone in the ovarian cysts and ovarian remnant tissue. For this purpose, a total of 31 domestic cats older than 1 year, including ORS (n = 9), OC (n = 3), spayed (n = 8), and intact (n = 11), were used in the study. Serum and intrafollicular AMH concentrations were determined by the electrochemiluminescence immunoassay, and expression of the AMH was determined by the immunohistochemical method. The serum AMH concentration in the ORS group was 1.49 ± 1.24 ng/ml (0.10-3.63 ng/ml) whereas it was 1.78 ± 0.92 ng/ml (0.8-2.63 ng/ml) in the OC group. AMH concentration in the intrafollicular fluid was determined as 0.023 ng/ml in a cat with an ovarian cyst. While the serum AMH concentration was below 0.01 ng/ml in spayed cats, it was 5.80 ± 3.30 ng/ml (1.88-11.86 ng/ml) in the intact cats. There was a significant difference between the spayed and intact groups in terms of serum AMH concentration (p < 0.05). Moreover, in cats with ovarian cyst and ovarian remnant syndrome, no difference was found between the groups in terms of serum AMH concentration (p > 0.05). No difference was found between the ovarian remnant syndrome and intact cats in terms of serum AMH concentration (p > 0.05). In immunohistochemical staining, ovarian cysts were found to be negative for AMH while a moderate (+2) AMH positivity was observed in other follicles. Furthermore, in cats with ovarian remnant syndrome, severe (+3) AMH positivity was observed. As a result, it was determined that gonadectomy status can be accurately diagnosed by the AMH measurement. Ovarian remnant syndrome cannot be diagnosed accurately by AMH measurement. In addition, it was found that AMH did not seem to play a role in the pathogenesis of ovarian cysts in cats.

Ultrasonographic Detected Adrenomegaly in Clinically Ill Cats: A Retrospective Study

This retrospective study aimed to assess the prevalence of ultrasonographic detected adrenomegaly in clinically ill cats, evaluating the final established diagnosis, describe adrenal ultrasound findings and if the adrenomegaly was suspected or incidental. Abdominal ultrasonography reports of cats presenting to a veterinary teaching hospital between October 2018 and February 2021 were retrospectively reviewed. Cats showing adrenomegaly (one or both glands having a dorsoventral axis >4.8 mm) were selected and medical records respectively evaluated. Nine-hundred and eighty-three ultrasonographical reports were selected, of which, 68 (7%) disclosed adrenomegaly. European/Domestic Short-Hair (62/68; 91%) male (44/68; 65%) castrated (35/44; 80%) cats were overrepresented. Adrenomegaly was an incidental finding in 62/68 (91%) cats while in 6/68 (9%) it was identified in the context of investigating a potential adrenal disease. Concerning established diagnosis, chronic kidney disease was overrepresented (25/68; 37%), followed by endocrinopathies (20/68; 29%). Adrenomegaly was bilateral in 53% (36/68) of cases. In unilateral cases (32/68; 47%), it was more prevalent on the left side (23/32; 72%), with a normal-sized contralateral adrenal gland. Left adrenal demonstrated a larger size and a tendency to oval shape. This study assesses the prevalence of adrenomegaly in clinically ill cats, reinforcing it can be an incidental ultrasound finding.

Anti-Müllerian hormone as a diagnostic tool to identify queens with ovarian remnant syndrome

OBJECTIVES

Ovarian remnant syndrome (ORS) is suspected when heat signs occur in spayed individuals, but further diagnostic procedures are necessary to exclude other possible oestrogen sources, such as the adrenal gland or exogenous supplementation. Anti-Müllerian hormone (AMH), secreted by granulosa cells or Sertoli cells, serves to differentiate sexually intact from gonadectomised animals and has been described in dogs as a tool for diagnosing ORS. The aim of this study was to evaluate if AMH determination can be used to diagnose ORS in cats.

METHODS

AMH was measured with a chemiluminescence immunoassay in serum samples of 15 sexually intact, 9 spayed and 16 cats with a history of heat signs after spaying. Abdominal ultrasound (n = 13), vaginal smears (n = 7), progesterone measurement (n = 5) and laparotomy (n = 14) were used to determine the presence of ovarian tissue. After surgery, a histological examination of the obtained tissue was performed in the cats with suspected ORS.

RESULTS

In 15 cats with ORS the AMH serum concentrations were significantly higher than in spayed cats (n = 10; P = 0.025) and significantly lower than in sexually intact cats (n = 15; P = 0.001). Among the cats with ORS, the highest AMH serum concentrations were measured in the queens with cystic ovarian alterations and in one cat from which a whole ovary was obtained. The cat with the lowest AMH serum concentration had a simultaneous high progesterone serum concentration. Cats with ORS did not show any heat signs after surgical removal of the ovarian tissue.

CONCLUSIONS AND RELEVANCE

A single determination of AMH in blood serum is a useful diagnostic tool for the diagnosis of ORS in cats, regardless of the hormonal activity of the remnant ovarian tissue.

Gynaecomastia in a male neutered cat with an adrenal tumour and associated hyperprogesteronism, hypercortisolism and hyperaldosteronism

Case summary

A 7-year-old male neutered domestic longhair cat was presented with chronic progressive gynaecomastia, polydipsia, polyphagia, weight loss and poor fur regrowth. Sexualised behavioural changes were not reported and virilisation was not present on physical examination. Pertinent haematology, biochemistry and urinalysis findings at the time of referral included mild hypokalaemia. Left adrenomegaly and mild prostatomegaly were identified on a CT scan. Evaluation of adrenal hormones with a low-dose dexamethasone suppression test, serum progesterone, testosterone, oestradiol, plasma aldosterone, renin, plasma metanephrine and normetanephrine measurement supported a diagnosis of hyperprogesteronism, hyperaldosteronism and hypercortisolism. Adrenalectomy was performed and histopathology was consistent with an adrenocortical tumour. Clinical signs and hormone elevations resolved postoperatively.

Relevance and novel information

To our knowledge, this is the second report of gynaecomastia secondary to an adrenal tumour in a male neutered cat and the first associated with hyperprogesteronism.

A case of behavioral changes in a castrated male cat due to a functional adrenocortical adenoma producing testosterone and androstenedione

Case summary

This case report describes a 9-year-old neutered male cat with a functional adrenal tumor showing aggression toward other cats in the household, excessive meowing and urine spraying. The diagnosis was made based on the clinical signs, an enlarged right adrenal gland on ultrasound, penile spines and elevated sex hormones on an adrenocorticotropic hormone stimulation test. The cat was submitted to celiotomy and adrenalectomy. Histopathological examination confirmed the adrenocortical adenoma. Three months after surgery the penile spines disappeared and urine spraying, as well as excessive meowing, had greatly decreased; however, aggressive behavior took much longer to stop and required behavior therapy.

Relevance and novel information

Functional adrenal tumors producing only sex hormones and behavioral changes are uncommon. The cat reported herein started showing behavioral changes before spines appeared on the penis, and structural alterations in the adrenal gland at the abdominal ultrasonography were detected. Considering all the possible implications resulting from severe behavior problems such as cat-cat aggression, from a permanent separation of the cats to relinquishment, a detailed investigation of underlying medical mechanisms in these animals is crucial from the start. Examinations may need to be repeated later in the course.

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.

Hyperandrogenism associated with an ovarian remnant in a spayed female cat

Case summary

An 11-year-old female, reportedly spayed, domestic shorthair cat was examined for a 4-month history of weight loss, aggression, urine spraying, malodorous urine and estrus-like behavior. Physical examination revealed thickened skin, a mildly prominent vulva and confirmed malodorous urine. On abdominal ultrasonography, a 6 mm hypoechoic nodule was found in the left cranial abdomen. An adrenocorticotropic hormone (ACTH) stimulation test with adrenal panel revealed elevated serum concentrations of androstenedione and testosterone pre- and post-cosyntropin stimulation, mildly decreased cortisol pre- and post-cosyntropin stimulation, and decreased resting aldosterone. Exploratory laparotomy was performed and a cystic, nodular mass was found in the region of the left ovary. The mass was surgically removed and submitted for histopathology; results were conclusive for an ovarian remnant with an intact corpus luteum and non-neoplastic parovarian cysts. Previously observed clinical signs resolved within two weeks of ovariectomy. A follow-up ACTH stimulation test with adrenal panel 6 weeks postoperatively revealed normalization of serum androstenedione, testosterone and cortisol concentrations. Four years postoperatively, at the time of writing, the cat remains free of clinical signs.

Relevance and novel information

We are unaware of any previously reported cases of non-neoplastic ovarian remnants associated with clinically relevant hyperandrogenism. A non-neoplastic ovarian-dependent hyperandrogenism should be included as a differential diagnosis of spayed female cats showing aggression and urine spraying behavior.

Mammary fibroadenomatous hyperplasia in a male cat

Case summary

Mammary fibroadenomatous hyperplasia (MFH) is a benign pathology characterised by extensive proliferation of the ductal epithelium and mammary stroma. It typically occurs in young female cats, and seems to result from hypersensitivity to progesterone. A 2-year-old entire male European Shorthair cat presented to the veterinary clinic with enlargement of several mammary glands, which had developed within the previous 10 days. There was no prior administration of progestin in the cat’s medical history. Diagnostic tests were performed to assess the basal progesterone concentration and the concentration after stimulation with gonadotropin-releasing hormone, which ruled out the presence of functional ovarian tissue. Histological examination of the testes excluded hormone-secreting testicular tumours. Histological examination of the mammary gland confirmed the diagnosis of MFH. Treatment was started with aglepristone, a selective competitor for progesterone receptors, administered subcutaneously at 15 mg/kg at days 1, 2, 8 and 15. A reduction in the size of the mammary glands was evident 6 days after the first administration, with complete remission observed after 4 weeks.

Relevance and novel information

To the best of our knowledge, this is the first full report of MFH in a male cat. Although the origin of the progestins responsible for MFH in this case could not be confirmed, in the light of the diagnostic tests performed and the results obtained, accidental contact with hormone-like substances seems to be the only plausible explanation for the cat’s clinical signs. Inhibitor therapy was successful.

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).

Clinical findings, diagnostics and outcome in 33 cats with adrenal neoplasia (2002-2013)

OBJECTIVES

The objective of this retrospective study was to describe the clinical signs and diagnostic findings in cats with histopathologically confirmed adrenal neoplasms, and to assess correlations with survival data.

METHODS

Study data were acquired by reviewing medical records for all cats diagnosed with adrenal neoplasms at seven referral institutions between 2002 and 2013. Inclusion criteria required a histopathologic diagnosis of an adrenal neoplasm (ante-mortem or on necropsy).

RESULTS

Thirty-three cats met the inclusion criteria for the study. The most common presenting complaints included weakness (n = 12), respiratory signs (n = 4), blindness (n = 4) or gastrointestinal signs (n = 3). Laboratory abnormalities included hypokalemia (n = 18), alkalemia (n = 12), elevated creatine kinase (>3000, n = 5) and azotemia (n = 4). In addition, hypertension was noted in 13 cats. Thirty cats were diagnosed with cortical tumors (17 carcinomas, 13 adenomas) and three cats were diagnosed with pheochromocytomas. Twenty-five cats underwent tests to evaluate the function of the adrenal tumors; 19/25 cats had functional tumors (hyperaldosteronism [n = 16], hypercortisolemia [n = 1], high estradiol [n = 1], and hypersecretion of aldosterone, estradiol and progesterone [n = 1]). Twenty-six cats underwent adrenalectomy, one cat was medically managed and six were euthanized without treatment. Long-term survival postoperatively ranged from 4-540 weeks, with 20 (77%) cats surviving the perioperative period of 2 weeks. The only variable that was found to be negatively associated with survival was female sex. The most common complications noted during the perioperative period were hemorrhage and progressive lethargy and anorexia.

CONCLUSIONS AND RELEVANCE

Surgical treatment for feline adrenal tumors (regardless of tumor type) resulted in good long-term survival. Given that pre- and postoperative hypocortisolemia was identified in this study, and, in addition, hypersecretion of more than one adrenal hormone occurred in one cat, adrenal panels prior to surgery may be beneficial as part of the preoperative work-up.

Clinical findings, diagnostic test results, and treatment outcome in cats with spontaneous hyperadrenocorticism: 30 cases

Background

Spontaneous hyperadrenocorticism (HAC) is rare in cats. Clinical findings, diagnostic test results, and response to various treatment options must be better characterized.

Objectives

To report the clinical presentation, clinicopathologic findings, diagnostic imaging results, and response to treatment of cats with HAC.

Animals

Cats with spontaneous HAC.

Methods

Retrospective descriptive case series.

Results

Thirty cats (15 neutered males, 15 spayed females; age, 4.0–17.6 years [median, 13.0 years]) were identified from 10 veterinary referral institutions. The most common reason for referral was unregulated diabetes mellitus; dermatologic abnormalities were the most frequent physical examination finding. Low‐dose dexamethasone suppression test results were consistent with HAC in 27 of 28 cats (96%), whereas ACTH stimulation testing was suggestive of HAC in only 9 of 16 cats (56%). Ultrasonographic appearance of the adrenal glands was consistent with the final clinical diagnosis of PDH or ADH in 28 of 30 cats (93%). Of the 17 cats available for follow‐up at least 1 month beyond initial diagnosis of HAC, improved quality of life was reported most commonly in cats with PDH treated with trilostane.

Conclusions and Clinical Importance

Dermatologic abnormalities or unregulated diabetes mellitus are the most likely reasons for initial referral of cats with HAC. The dexamethasone suppression test is recommended over ACTH stimulation for initial screening of cats with suspected HAC. Diagnostic imaging of the adrenal glands may allow rapid and accurate differentiation of PDH from ADH in cats with confirmed disease, but additional prospective studies are needed.

Elevated Testosterone and Progestin Concentrations in a Spayed Female Rabbit with an Adrenal Cortical Adenoma

This case was described briefly in a recent book chapter (Lennox AM, Fecteau KA: 2014, Endocrine disease. In: BSAVA Manual of Rabbit Medicine, eds. Meredith A, Lord B, pp 274–276. British Small Animal Veterinary Association, Gloucester, UK). In the previous description, the tumor was described as a pheochromocytoma; however, further evaluation suggested that it more closely resembled an adrenal cortical adenoma. A 10-year-old, spayed female rabbit was presented for a behavior change of 8 months’ duration. The rabbit was inappropriately urinating and defecating, as well as demonstrating aggressive behaviors such as chasing, biting, and mounting various objects. The rabbit had elevated progesterone, 17-hydroxyprogesterone, and testosterone concentrations, and ultrasound examination of the abdomen showed a round, homogenous nodule measuring 1.1 × 0.8 × 0.9 cm in the region of the left adrenal gland. Necropsy revealed a unilateral adrenal cortical adenoma. To the authors’ knowledge, this is the first complete description of a female rabbit with an adrenal cortical adenoma documented in the literature.

GATA4 is a critical regulator of gonadectomy-induced adrenocortical tumorigenesis in mice

In response to gonadectomy certain inbred mouse strains develop sex steroidogenic adrenocortical neoplasms. One of the hallmarks of neoplastic transformation is expression of GATA4, a transcription factor normally present in gonadal but not adrenal steroidogenic cells of the adult mouse. To show that GATA4 directly modulates adrenocortical tumorigenesis and is not merely a marker of gonadal-like differentiation in the neoplasms, we studied mice with germline or conditional loss-of-function mutations in the Gata4 gene. Germline Gata4 haploinsufficiency was associated with attenuated tumor growth and reduced expression of sex steroidogenic genes in the adrenal glands of ovariectomized B6D2F1 and B6AF1 mice. At 12 months after ovariectomy, wild-type B6D2F1 mice had biochemical and histological evidence of adrenocortical estrogen production, whereas Gata4(+/-) B6D2F1 mice did not. Germline Gata4 haploinsufficiency exacerbated the secondary phenotype of postovariectomy obesity in B6D2F1 mice, presumably by limiting ectopic estrogen production in the adrenal glands. Amhr2-cre-mediated deletion of floxed Gata4 (Gata4(F)) in nascent adrenocortical neoplasms of ovariectomized B6.129 mice reduced tumor growth and the expression of gonadal-like markers in a Gata4(F) dose-dependent manner. We conclude that GATA4 is a key modifier of gonadectomy-induced adrenocortical neoplasia, postovariectomy obesity, and sex steroidogenic cell differentiation.

Animal models of adrenocortical tumorigenesis

Over the past decade, research on human adrenocortical neoplasia has been dominated by gene expression profiling of tumor specimens and by analysis of genetic disorders associated with a predisposition to these tumors. Although these studies have identified key genes and associated signaling pathways that are dysregulated in adrenocortical neoplasms, the molecular events accounting for the frequent occurrence of benign tumors and low rate of malignant transformation remain unknown. Moreover, the prognosis for patients with adrenocortical carcinoma remains poor, so new medical treatments are needed. Naturally occurring and genetically engineered animal models afford a means to investigate adrenocortical tumorigenesis and to develop novel therapeutics. This comparative review highlights adrenocortical tumor models useful for either mechanistic studies or preclinical testing. Three model species - mouse, ferret, and dog - are reviewed, and their relevance to adrenocortical tumors in humans is discussed.