Ectopic ACTH Syndrome (EAS) – an Unusual Suspect for Profound Immunosuppression

Presentation Number: SUN-0776
Date of Presentation: June 22nd, 2014

Oren Steen*, Karan Bami, Winnie Chan, Nishma Singhal and Ally P.H. Prebtani
McMaster University, Hamilton, ON, Canada

Abstract

Introduction: Severe hypercortisolism may cause immunosuppression leading to opportunistic infections.

Clinical Case: A 74 year-old female presented to hospital with progressive fatigue, weight loss and generalized weakness. She was newly diagnosed with hypertension, diabetes mellitus and severe hypokalemia. Examination revealed cachexia and profound muscle weakness; she lacked classic Cushingoid features. Investigations revealed a 24 hour urinary free cortisol of 11328 nmol (n<300 nmol) and plasma ACTH of 112 pmol/L (n<10.3 pmol/L). Cortisol levels did not suppress after 8 mg overnight dexamethasone suppression (2279 nmol/L pre-dex; 2549 nmol/L post-dex). She was diagnosed with ectopic ACTH syndrome (EAS).

CT of the chest, abdomen and pelvis was unremarkable aside from bulky adrenal glands, while octreotide scan showed increased uptake in the left adrenal. No lesion was seen on MRI sella with gadolinium. She was started on insulin for diabetes, and spironolactone and potassium replacement for hypertension and hypokalemia. She was discharged home with endocrine follow-up.

Within days, the patient was readmitted with confusion and functional decline. She deteriorated despite management with ketoconazole and octreotide for hypercortisolemia, and was intubated for decreased level of consciousness. She developed an upper GI bleed. Upper endoscopy revealed CMV duodenitis and she was treated with gancyclovir. HIV serology was negative. Trimethoprim-sulfamethoxazole (TMP-SMX) was initiated for PJP prophylaxis.

Adrenal vein sampling (performed in light of the previous octreotide scan result) did not demonstrate an ACTH gradient. Given her clinical deterioration without an identifiable source of ACTH, she underwent urgent bilateral adrenalectomy. Postoperatively, her hypokalemia resolved, and she was weaned off antihypertensives and insulin. Meanwhile, her respiratory status worsened, and bronchoalveolar lavage detected PJP (despite TMP-SMX prophylaxis) and subsequently also grew Mycobacterium tuberculosis. She was treated for both of these. She also developed hemorrhagic cystitis, possibly secondary to BK virus.

The patient was eventually extubated and required extensive rehabilitation prior to being discharged home with endocrine follow-up and continual surveillance for an ACTH source.

Conclusion: Prompt identification and treatment of hypercortisolemia are vital for the successful management of EAS complications. When a source cannot be found, bilateral adrenalectomy may be necessary to control symptoms and reduce the risk of immunosupression in severely ill patients. This case uniquely demonstrates a case of EAS resulting in infections with CMV, PJP, TB and possibly BK virus. It highlights the profound degree of immunosuppression these patients can experience and the need to maintain a high index of suspicion for multiple opportunistic co-pathogens.

 

Nothing to Disclose: OS, KB, WC, NS, APHP