Concomitant multiple myeloma and probable phaeochromocytoma in a cat

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.

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.

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.