Clinicopathological Evaluation of Extragonadal Germ Cell Tumors - A Retrospective Study from a Regional Cancer Center in India

Introduction: Extragonadal germ cell tumors (EGGCTs) are tumors arising at extragonadal ana-tomical locations. The biological behavior and prognosis of these tumors differ from their gonadal counterparts. Our study aims to analyze their histological subtypes, the outcome, and the prognosis of these lesions at various age groups. Material and Methods: We carried out a retrospective analysis of all patients with EGGCTs diag-nosed from January 2017 to December 2019. Results: Our study included 61 cases of EGGCTs. These cases were divided into neonatal (birth to six months), prepubertal (more than six months to 12 years), and post-pubertal group (>12 years). The most frequently affected group was prepubertal (44.2%). The age ranged from birth to 45 years with a male-to-female ratio of 1:1.03. The frequently involved site was sacrococcyx (36%) followed by mediastinum (31.1%). The common histologic subtype was mature teratoma (39.3%), followed by yolk sac tumor (YST) (18%), mixed germ cell tumor (18%), immature teratoma (14.7%), and germinoma (9.8%). Four cases of teratoma had somatic malignancies. There were 48 stage I, 8 stage II, and 2 stage III tumors. Statistical analysis revealed a significant association of age group concerning primary site (p=0.004), histological type (p=0.002), and clinical stage (p=0.034). In a median follow-up of 30 months, an Overall Survival (OS) of 93.2% and Event Free Survival (EFS) of 90.4% were noted across all age groups. OS of 100% (neon tal), 96% (prepubertal) and 88.0% (post-pubertal) revealing a declining trend (p=0.324) with increasing age was noted. The important prognostic factors include histological subtype (mixed germ cell tumors and teratomas with somatic malignancies had reduced overall survival) and stage (I vs II and III) for OS and stage alone for EFS (P