Clinicopathological Evaluation Of Yolk Sac Tumor Of Testis: A Case Report

Abstract

Background: Yolk sac tumor (endodermal sinus tumor) is a malignant germ cell neoplasm and represents the most common malignant
testicular germ cell tumor in infants and young children. It is characteristically associated with elevated serum alpha-fetoprotein (AFP)
levels and demonstrates distinctive histopathological features that aid in diagnosis.
Case Presentation: A 2-year-old male child presented with a painless right scrotal swelling of three months’ duration. Ultrasonography
revealed a 5.2 × 4.6 × 4.1 cm heterogeneous solid intratesticular mass with prominent internal vascularity. Serum alpha-fetoprotein was
markedly elevated at 18,650 ng/mL, while serum beta-human chorionic gonadotropin was <2 mIU/mL and lactate dehydrogenase was
286 U/L. The patient underwent right radical inguinal orchiectomy. Gross examination revealed a 5.0 cm yellowish, soft to mucoid
tumor with focal hemorrhage and necrosis. Microscopic examination demonstrated a predominantly reticular/microcystic pattern
with characteristic Schiller-Duval bodies. PAS staining demonstrated PAS-positive hyaline globules. Immunohistochemistry showed
strong AFP, SALL4, and glypican-3 positivity, with negative OCT3/4 and CD30 expression. The findings confirmed the diagnosis
of pure prepubertal-type yolk sac tumor.
Conclusion: Yolk sac tumor is an aggressive yet highly treatable malignancy in pediatric patients. Early diagnosis through correlation
of clinical findings, age-adjusted serum AFP, imaging, histopathological examination, and immunohistochemistry is essential for
appropriate management and favorable outcome. Recognition of Schiller-Duval bodies, reticular/microcystic architecture, and PASpositive
hyaline globules provides important diagnostic clues.