[Pseudo-Cushing states]

Stress as cause of signs and symptoms of pseudo-Cushing's syndrome in buffy-tufted marmosets (Callithrix aurita)

Hyperadrenocorticism is a medical condition caused by the increase in cortisol production by the cortex of the adrenal gland. Although infrequently described in most animal species, its naturally occurring form, called Cushing's syndrome, is the most prevalent endocrinopathy in dogs. Cushing's syndrome is also present in humans and might be confused with the pseudo-Cushing's syndrome (PCS), rarely described in animals. PCS shares many of the clinical and biochemical features of Cushing's syndrome. However, the hypercortisolemia seen is usually idiopathic and, in some circumstances, associated with psychological disruptions. This report describes PCS-like disorder in two marmosets Callithrix aurita that were exposed to environmental changes, suggesting stress as the main cause of the process and reviewing the mechanisms involved in the pathogeny of the two syndromes.

Current status on histological classification in Cushing's disease

INTRODUCTION

Managing Cushing's disease remains a challenge. Surgery is the first option of treatment and it offers a high success rate. Even in cases where biochemical remission is not achieved, it is crucial to obtain surgical tissue for morphological diagnosis because the therapeutic approach can be modified according to the findings.

MATERIALS AND METHODS

A literature search was performed using PubMed for information regarding pathology and Cushing's disease.

RESULTS

The histopathological features found in the pituitary gland of patients with Cushing's disease are presented.

CONCLUSION

Different subtypes of ACTH-producing pituitary tumors are recognized and characterized. The significance of finding a normal pituitary gland with or without Crooke's changes is also discussed.

[Diagnosis and differential diagnosis of Cushing's syndrome]

Because of the variability in the clinical expression of Cushing's syndrome, different biochemical tests and imaging techniques must be used for effective diagnosis and treatment. The clinical history is important to assess the general impact of hypercortisolism on organs and systems, as well as to guide suspicion toward more aggressive entities such as overt ectopic ACTH syndrome or to detect an iatrogenic etiology of Cushing's syndrome. The screening phase relies on tests that are sensitive but not specific, such as urinary free cortisol, nocturnal salivary cortisol and 1 mg dexamethasone suppression, which still require established assessment criteria. Confirmation can be obtained by repeating urinary cortisol, 2 mg/day dexamethasone suppression, both alone and combined with corticotropin releasing hormone (CRH), to exclude pseudoCushing states. ACTH dependency can be easily explored by ACTH measurements, but the differential diagnosis between pituitary and ectopic Cushing's disease is difficult and may require invasive procedures such as inferior petrosal sinus sampling. Sophisticated imaging and isotopic techniques play a significant role in locating the source of ACTH in ectopic syndromes but are not always effective. In general, biochemical and imaging tests should be combined in order to assess different mechanisms and perspectives of the syndrome. Rigorous methodology is essential to obtain accurate results, allowing a correct diagnosis and improving therapeutic performance in this devastating disease.