6702 Management And Complications Of Metastatic Adrenocortical Carcinoma Presenting With Severe Cushing Syndrome

Abstract Disclosure: S. Rodrigues: None. A.K. Sumal: None. Background: Metastatic adrenocortical carcinoma (ACC) presenting with Cushing syndrome (CS) is a complicated, aggressive disease that commonly requires multiple adrenal steroidogenesis inhibitors and chemotherapy to achieve hormonal and tumor control. Clinical Case: A 66-year-old man with a history of prostate cancer and hypertension presented with right flank and back pain, worsening type 2 diabetes, profound proximal muscle weakness, and 3+ lower extremity edema to his thighs. CT and PET-CT revealed a 10.9 cm right adrenal mass with pericaval lymphadenopathy and metastatic disease at the L2 vertebral body. Laboratory testing demonstrated evidence of hypercortisolism with elevated 24-hour urinary cortisol excretion (449 mcg/24h; n<45 mcg/24h), and abnormal 1 mg dexamethasone suppression test (cortisol 15 mcg/dL; n< 1.8 mcg/dL) with suppressed ACTH (<6 pg/mL; n=7-63 pg/mL). Surgical resection of the primary tumor was aborted intraoperatively given the discovery of new peritoneal metastases, which were confirmed by biopsy to be metastatic ACC. He was started on mitotane and osilodrostat to manage his severe CS. He was also started on dexamethasone, both to prevent adrenal insufficiency and to avoid influencing serum cortisol measurements used to assess disease control. However, given his significant peripheral edema and weakness, he was functionally unable to receive chemotherapy. Despite rapid uptitration of mitotane and osilodrostat over three weeks, his CS remained uncontrolled, and he was ultimately hospitalized for lower extremity paralysis and septic shock due to pyelonephritis. Repeat imaging revealed severe spinal canal stenosis from an L2 pathologic fracture, as well as worsening hepatic, osseous, peritoneal, and retroperitoneal metastases. After recovery from his septic shock, he was started on chemotherapy with carboplatin and etoposide while hospitalized, but his mitotane was intermittently held due to elevated transaminases. His hospital course was complicated by hypotension requiring pressor support, atrial fibrillation, hemoperitoneum, worsening anasarca, and acute kidney injury requiring continuous renal replacement therapy. Given his worsening condition that precluded him from further chemotherapy or palliative radiation, he elected to pursue comfort care measures and expired shortly thereafter. Conclusion: This case highlights the therapeutic challenges of metastatic ACC presenting with life-threatening CS. Simultaneous use of multiple adrenal steroidogenesis inhibitors is often required for control of hypercortisolism, and chemotherapy is equally necessary to manage tumor burden. However, as in this case, disease-related complications can limit treatment management and result in rapid deterioration. Thus, early diagnosis and prompt treatment of metastatic ACC presenting with CS is critical to prevent morbidity and mortality. Presentation: 6/3/2024