SAT337 Maternal Cell free DNA Testing Reveals Incidental Finding Of Adrenocortical Carcinoma

Disclosure: F. Akanbi: None. S. Raja: None. T. Else: None. Maternal Cell-free DNA Testing Reveals Incidental Adrenocortical Carcinoma IntroductionAdrenocortical carcinoma (ACC) is rare; with 1 to 2 cases per million. It is unclear if ACC in pregnancy represents a specific association though 150 cases have been reported. We report a case of ACC detected during fetal sex determination using cell free DNA (cfDNA). Case Report: A 30 year old G1P0 woman presented at GA of 25 weeks with results of non-invasive prenatal screening (NIPS) done for fetal sex determination, which noted atypical findings concerning for possible maternal neoplasm. Pregnancy had been uncomplicated; she had no significant past medical history or features of hypercortisolism. Family history was positive for lung and prostate cancer. Physical examination revealed healthy looking female with no Cushingoid facies, abdomen matched stated GA. Full body MRI revealed 5.5 cm right adrenal mass with lymph nodes metastases. CT-guided retroperitoneal lymph node biopsy showed ACC.She was asymptomatic with significantly elevated urine free cortisol 3648 (3.5-45 mcg/24 hour), serum cortisol 67.5 (5-25 ug/dl), 11-deoxycortisol 3910 (10-79 ng/dl), and suppressed ACTH <5 (5-52 pg/ml). Electrolytes were normal, DHEAS 342 (35-430 ug/dl), aldosterone < 3 (4-31 ng/dl), renin mass 5 (4-44pg/ml), urinary free normetanephrine 0.23 (< 0.9 nmol/l), urinary free metanephrine < 0.2 (< 0.5 nmol/l). MRI of the chest and brain did not show metastases. She developed at GA 29 weeks, hypertension, proteinuria, and transaminitis. Cesarean section was done at GA 30 weeks followed the next day by right adrenalectomy, IVC repair and retroperitoneal lymph node resection. Pathology showed high-grade adrenal cortical carcinoma (12 cm size) with negative margins, vascular invasion and lymph node involvement (T3, N1, M0), no caval involvement, stage III ACC. During chemotherapy planning, metastases were noted, mitotane and pembrolizumab were initiated, but discontinued after 2 cycles on account of generalized rash and elevated liver enzymes. The tumor progressed on etoposide, doxorubicin and cisplatin (EDP), and second line therapy (gemcitabine and capecitabine) was initiated. Conclusion: Physiologic changes of pregnancy mimic clinical features of ACC and pregnancy associated changes in the HPA axis also make ACC diagnosis challenging. Short fragments of DNA (cfDNA) released into the maternal bloodstream can be detected after 7 weeks of gestation. Approximately 2-20% of total cfDNA is placental, it is used for sex determination and detection of congenital genetic abnormalities, cfDNA can also originate from maternal neoplasms and has been shown to detect lung, breast and colon while case series in patients with ACC showed detection of only 1 out of 3 cases. Surgery remains first line therapy for ACC, but adjuvant therapy, surveillance and hormone replacement are also vital in ACC management. Presentation: Saturday, June 17, 2023