8659 Aldosterone-Secreting Adrenocortical Carcinoma: A Rare Cause Of Primary Hyperaldosteronism Associated With Dismal Outcome

Abstract Disclosure: S. Beeby: None. C.H. Huzita: None. F.Q. Aratani: None. L.S. Motomia: None. F. Coelho: None. M. Polo: None. C.R. Victor: None. A.O. Hoff: None. J. Chambo: None. V. Srougi: None. F. Ledesma: None. A. Latronico: None. M.Q. Almeida: None. B.B. Mendonca: None. M.C. Fragoso: None. Background: Adrenocortical carcinoma (ACC) is a rare and one of the most aggressive solid tumors, with an incidence of 1-2 cases per million. In adults, hormonal excess is usually manifested by ACTH-independent Cushing's syndrome or mixed endocrine syndrome due to cortisol and androgen production. Isolated aldosterone secretion is an extremely rare condition, with an estimated 2.5% of patients with ACC. We aimed to describe two patients with aldosterone-secreting ACC with poor outcomes. Case 1 - A 34-year-old male who was diagnosed with hypertension at 29 years of age, associated with hypokalemia needing intravenous potassium replacement therapy. Diagnosis of primary hyperaldosteronism was established with aldosterone levels of 72 ng/dL (RR < 23.1 ng/dL) and renin activity of 1.1 ng/mL/h (RR 0.3 to 5.8 ng/mL/h. An abdominal CT scan identified a tumor mass of 9.5 x 8.0 x 4.5 cm. He underwent a left adrenalectomy and histological and immunohistochemistry data suggested an adrenocortical carcinoma (modified Weiss score 5/7, Ki67 40%). Initial staging was ENSAT III and a Helsinki score of 48. There was transient improvement, however recent laboratory studies showed an increase in aldosterone (66,9 ng/dL) accompanied by new episodes of hypokalemia. CT scans on follow-up showed recurrence of disease, with the presence of nodules on the surgical site and abdominal wall. He received 3 lines of systemic chemotherapy and mitotane and underwent 2 other surgical procedures to treat the metastatic lesions. Currently, overall survival is 3 years. Case 2 - A 44-year-old female incidentally found a right adrenal mass (6.6 x 6.4 cm) on MRI during the investigation of elevated liver enzymes and abdominal pain. Laboratory studies showed hypokalemia, with potassium levels of 2 mEq/L (RR 3.5-5 mEq/L), aldosterone levels of 243 ng/dL (RR < 23.1 ng/dL), and renin of 12.2 uUI/mL (RR 4.4 - 46.1 uUI/mL). She underwent right adrenalectomy and histology and immunohistochemistry data showed a modified Weiss 7/7 and Ki67 of 80%. The patient had a germline pathogenic variant of TP53 (p.R337H). Initial staging was ENSAT III and a Helsinki score of 88. She received adjuvant mitotane and systemic chemotherapy. Even so, follow-up imaging showed hepatic metastatic disease, with an elevated aldosterone production surpassing 1000 ng/dL. The patient's overall survival was 2 years and she passed away during surgical procedure for resection of liver metastases. Discussion: ACC is a rare and aggressive tumor, and isolated aldosterone production by such tumors is extremely rare. We presented two cases with poor prognostic features and in which despite adjuvant mitotane and systemic chemotherapy there was disease progression. Due to the rarity of this condition, data on patient outcomes is limited, and further understanding of the molecular signature of these tumors could bring new insights on the tumorigenesis process. Presentation: 6/3/2024