1. Extragonadal Yolk Sac Tumors Case presentation and review Jason Hurd

2. Outline Case: 17 month old male w/abdominal mass Background and review of the literature Presentation and management Follow-up

3. Case Presentation: Initial workup 17m previously healthy M with abd mass identified on day of presentation by OSH US HPI: Abd distention/pain, fevers for 6 days Increased pain on day of admission = PCP visit Outside US: 10 x 9.8 x 7.9 cm R abd mass Referred to SCH

4. Case Presentation: SCH Presented to SCH ED Increasing abdominal pain, anorexia PE: Tender, firm right-sided abd mass with moderate distension CT Thorax/Abdomen/Pelvis: ▫11.1 x 10.6 x 7.8 cm right abdominal mass ▫Inferior edge of liver to upper pelvis ▫No organ involvement ▫Ascites c/w necrotic debris/blood, LAD

5. CT Thorax/Abdomen/Pelvis CIS Image Differential diagnosis

6. Case Presentation: OR Course Taken to OR for ex lap and excisional bx next am Tumor adherent to anterior abdominal wall, posterior fascia, w/other adhesions to TI and transverse colon Frozen section: malignant, non-neuroblastoma Blood supply arising from mesentery Removed tumor Peritoneal implants biopsied

7. Case Presentation: Diagnosis Surgical Pathology: Metastatic yolk sac tumor Elevated AFP: 98,000 Normal testicular US Unique presentation – likely primary abdominal Arising from mesentery based on OR findings

8. Background: Germ Cell Embryology YST: Common Pediatric Germ Cell Tumor GCs are gamete precursors Develp in dorsal endoderm Migrate along midline to primitive gonad in 4 th – 5 th wk gestation Melmed: Williams Textbook of Endocrinology, 12 th Ed.

9. Background: Pathogenesis Extragonadal GCTs arise from defect in migration, malignant degeneration Two competing theories: ▫Mismigration of GCs, persistent survival outside gonads ▫Reverse migration ▫Usually develop along midline Wein: Cambell-Walsh Urology, 10 th Ed.

10. Extragonadal Yolk Sac Tumors Majority of YSTs occur in gonads Yolk sac tumors: most common pediatric GCT 10-15% of YSTs in extragonadal locations Usually in mediastinum, brain, vagina, retroperitoneum, sacrococcygeal Mckenney, et al. Extragonadal yolk sac tumors. Adv Anat Pathol 2007;14:69–92. Munghate, et al. Primary yolk sac tumor of the common bile duct. J. Ped Surg (2011) 46, 1271–1273.

11. Literature Review Multiple case reports Variety of locations reported: Pancreas, CBD, omentum, thyroid, oropharynx, intraocular One report of pediatric primary mesenteric YST in two patients, ages 2 and 17 Jones et al. Primary yolk sac tumors of the mesentery: A report of two cases. Am J Clin Pathol. 1994 Jan;101(1):42-7

12. Presentation Varies depending on location Abdominal distension Pain Elevated AFP Ultrasound/CT showing mass Xinghui et al. Endodermal sinus tumor of the omentum in a child. Pediatr Radiol (2004) 34: 985–987

13. Management: Medical vs Surgical Three decades ago: Uniformly fatal Advances in chemotherapy Current Ctx: Bleomycin, Etopside, Cisplatin Debate: When to operate? Biopsy? Need definitive pathological diagnosis Decision making in our case

14. Prognosis 299 pt RCT published in 2004 Pediatric pts with malignant GCTs Bleomycin, etopside, cisplatin compared to previous therapy of cisplatin alone 89.6% six-year survival rate Cushing, et al. Randomized comparison of combination chemotherapy with etoposide, bleomycin, and either high-dose or standard-dose cisplatin in children and adolescents with high-risk malignant germ cell tumors: a pediatric intergroup study--Pediatric Oncology Group 9049 and Children's Cancer Group 8882. J Clin Oncol. 2004 Jul 1;22(13):2691-700

15. Follow-up: Post-Operative Course Pain control issues on POD 1, 2 Central line placed POD 4 PO pain meds, adv diet by POD 5 Transferred to heme/onc POD 6 for ctx Discharged home off pain meds on POD 11 Follow-up appointment today w/heme-onc AFP down from 98,000 on 7/6 to 34,100 on 7/12

16. Conclusion Extremely rare presentation of common malignancy Worth reporting Questions?