P0774 - HCC Screening in Patient With NASH Leading to Rare Incidental Finding: Metastatic Mixed Germ Cell Tumor Diagnosed in an Older Male

Teea Bunker, DO, Zachary Johnston, MD, Dawn Torres, MD
Walter Reed National Military Medical Center, Bethesda, MD

Introduction: The increasing prevalence of nonalcoholic steatohepatitis (NASH) has led many to consider hepatocellular cancer (HCC) screening in this population. This case report details a 60-year-old man undergoing HCC screening who was ultimately diagnosed with mixed metastatic germ cell tumor (GCT). Testicular cancer accounts for only one percent of all cancers in men and most commonly occurs before the age of 35. Over the age of 50, the frequency of GCT drastically decreases.

Case Description/Methods: A 60-year-old man was undergoing screening liver magnetic resonance imaging as part of a clinical treatment trial for his recently diagnosed Stage 3 NASH. He was found to have a 3.8 cm retroperitoneal mass in the lower abdomen abutting the inferior vena cava. A Dotatate positron emission tomography scan redemonstrated the mass as well as a slightly enlarged and prominent left testicle with hypermetabolism. Findings from this PET/CT were originally concerning for a neuroendocrine origin of the tumor. However, upon resection of the mass, pathology revealed metastatic mixed germ cell tumor comprised of 70% mature teratoma and 30% yolk sac tumor. A testicular ultrasound revealed a 4 mm mass on the right teste likely representing a ‘burned out’ GCT. He is currently undergoing evaluation for treatment including radical orchiectomy of the right teste and systemic chemotherapy.

Discussion: Incidental findings on surveillance imaging studies are relatively common, occurring in up to 13% of the population. Potentially serious incidental findings are more rare at 1.9%.₁ Testicular GCT are very unusual to be diagnosed over the age of 50 with an incidence of 0.34 per 100,000.₂ These tend to be a higher stage at diagnosis with a lower response to initial chemotherapy, and higher rate of disease progression, resulting in an increased mortality rate in this older population. We aim to highlight a rare clinical entity encountered in this older male as well as highlight the importance of incidental findings in HCC screening.

1. Gibson LM et al. Potentially serious incidental findings on brain and body magnetic resonance imaging of apparently asymptomatic adults: systematic review and meta-analysis. BMJ. 2018;363:k4577. Published 2018 Nov 22. doi:10.1136/bmj.k4577
2. Ghazarian AA et al. Testicular cancer among US men aged 50 years and older. Cancer Epidemiol. 2018;55:68-72. doi:10.1016/j.canep.2018.05.007


Disclosures:
Teea Bunker indicated no relevant financial relationships.
Zachary Johnston indicated no relevant financial relationships.
Dawn Torres indicated no relevant financial relationships.


Teea Bunker, DO, Zachary Johnston, MD, Dawn Torres, MD. P0774 - HCC Screening in Patient With NASH Leading to Rare Incidental Finding: Metastatic Mixed Germ Cell Tumor Diagnosed in an Older Male, ACG 2021 Annual Scientific Meeting Abstracts. Las Vegas, Nevada: American College of Gastroenterology.