Ovarian teratomas in children are the most common germ cell tumors. Can be mature, immature and malignant. The vast majority of ovarian teratoma are mature. Ovarian immature teratomas (OIT) represent 1% of ovarian tumors graded according to the proportion of tissue containing immature neural elements. More than 80% of immature teratoma has elevated levels of alpha-fetoprotein. Tumors with higher AFP levels exhibit additional foci of malignant germ cell components. Peak incidence occurs between 15 and 19 years of age presenting as pelvic mass, abnormal uterine bleeding, abdominal pain or abdominal distension. US shows a complex ovarian lesion (solid and cystic components) or a heterogenous lesion in CT-Scan. Fat and scattered calcifications can also be present. Staging represents findings at surgery whether the tumor is confined to the ovary, peritoneum, pelvis, lymph node, adjacent organs, bilateral or has malignant ascites. Grade refers to pathologic presence of immature tissue in lower power field. Immature teratomas behave in a malignant fashion only if foci of malignant germ cell elements (yolk sac tumor) are present or if they are resected incompletely giving rise to the growing teratoma syndrome. Grade at diagnosis is the most important risk factor for relapse across all age groups. In children with grade 1 and 2 tumors there are no relapse regardless of stage. The majority of relapses (20%) occur in children with grade 3 tumors. Grade 3 with stage I/II disease have excellent free survival in comparison with stage III/IV. Completeness of resection influences free survival. Most children with OIT will not need chemotherapy. Grade, stage and completeness of resection are important risk factors for relapse. Recurrent disease occurs within the pelvis at the site of the original tumor. Tumor size does not correlate with tumor grade. The management of ovarian immature teratoma is unilateral salpingo-oophorectomy plus comprehensive staging. Complete resection is a key factor in avoiding tumor relapse. Routine biopsy of the unaffected ovary is unnecessary because immature teratoma is almost always unilateral. Lymphadenectomy does not provide any significant benefit to the survival of patients affected by immature teratoma. The reason to remove the tube with the tumor is to reduce an ectopic pregnancy risk. Initial adjuvant chemotherapy does not reduce future relapse or progression in OIT. Ovarian-sparing surgery during tumorectomy is an option being studied and depends on the anatomic feasibility of each case. Adjuvant chemotherapy is use for residual or recurrent disease though it may cause growing teratoma syndrome. Children with OIT should be follow-up with serial US and AFP levels.
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