Endocrine Abstracts

Introduction: The diagnosis of Cushing’s syndrome (CS) can be challenging for endocrinologists due to its multifaceted presentation. Accurate differentiation between Pseudo-Cushing syndrome (PCS) and true CS is crucial as their treatment approaches and outcomes vary significantly.

Case Report: A 43-year-old male patient with grade III obesity (BMI: 49.9 kg/m²) presented to our Endocrinology outpatient clinic with a complex medical history including hypertension, impaired fasting glycemia, Basedow disease and recent hypogonadism. The patient reported a rapid and substantial weight gain of approximately 60 kg within 5 months during the Covid-19 pandemic. Physical examination revealed a ‘cushingoid’ appearance with facial plethora, central obesity, striae rubrae, and retronucal adipose tissue deposition. The patient underwent initial investigations for endogenous hypercortisolism, including overnight 1 mg dexamethasone suppression test (DST), urinary-free cortisol test, ACTH test. However, the results did not fully meet the diagnostic criteria for endogenous hypercortisolism. Therefore, an oral 2-mg 48-h low-dose dexamethasone suppression test (LDDST) was performed, revealing a lack of suppression of serum cortisol level and thus confirming the diagnosis of endogenous hypercortisolism. To investigate the possibility of Cushing Disease (CD), a 3 Tesla dynamic contrast-enhanced magnetic resonance imaging (MRI) was performed, revealing an area of delayed enhancement in the left half of the gland, measuring approximately 4 mm, and suggestive of microadenoma. Despite this finding, the possibility of PCS could not be ruled out, as the patient reported emotional distress and depressed mood despite denying alcohol consumption. The patient underwent a combined LDDST-CRH test. The basal cortisol level before CRH infusion was 30.5 nmol/l, and the cortisol level 15 minutes after CRH infusion was 35.7 nmol/l (<39 nmol/l). Although the result was not definitive, it indicated the possible presence of PCS and, therefore a ’wait and see’ approach was adopted. The patient was started on a low-calorie diet and received medical treatment to manage comorbidities. A follow-up biochemical assessment was conducted after 3 months, which confirmed the diagnosis of PCS with concomitant non-functioning pituitary microadenoma. The patient exhibited remarkable compliance with the recommended diet, leading to a substantial weight loss of 25 kg. Additionally, diabetes and hypertension appeared well-controlled.

Conclusion: Differential diagnosis between CD and PCS is complex and may require multiple tests over time. The possibility of pituitary incidentalomas on MRI should always be considered. In cases where there is uncertainty regarding the diagnosis, a follow-up evaluation of the patient at 3-6 months, both clinically and biochemically, can be useful.