| خلاصه مقاله | Ovarian malignancy, in children and adolescents is reported in 10%–20% of all ovarian masses or neoplasms and comprises approximately 1%–2% of all childhood malignancies. These tumors are rare compared with in adults but are the most common genital tumor, accounting for 60%–70% of all gynecologic malignancies in this age group. ovarian tumors constitute an important part of pediatric oncology and often create diagnostic dilemmas. germ cell tumors(GCTs), are the most common type(60%–80%) of pediatric ovarian tumor, followed by surface epithelial stromal tumors and sex cord–stromal tumors(SCSTs) and dysgerminoma is the most common malignant GCT in childhood and adolescence. Ovarian teratoma is composed of mature or immature tissues derived from more than one of the three primitive embryonic layers (ectoderm, mesoderm, and endoderm) and some are incidental findings and can become apparent as a large painless mass. they can also twist, especially when the diameter is > 5 cm and cause an acute abdomen. Sacrococcygeal teratoma is arising in the sacrococcygeal region and composed of all three germ cells.it is most common congenital tumor in the fetus and neonate and thought to arise from totipotent cells from the node of Hensen at the anterior aspect of the coccyx and thus coccyx is almost always involved. Rhabdomyosarcoma is the most common soft tissue tumors, in children and can develop almost anywhere but mostly in the head and neck region and in the genitourinary tract and the age of the patient, generally below 15 years. Ewing sarcoma, is second most common malignant primary bone tumors of childhood (after osteosarcoma) and usually present as moth-eaten, destructive, and permeative lucent lesions in the shaft of long bones, with a large soft tissue component and typical onion skin periostitis. These tumors may also involve flat bones and can appear sclerotic in up to 30% of cases. |