title: [Pelvic retroperitoneal teratoma. A case report].
abstract: Teratomas are congenital tumors comprising of tissues arising from pluripotent embryonic cells. Their common sites of occurrences are ovary, testis, mediastinum and retroperitoneum. Retroperitoneal teratomas are extremely rare in adults but occur in 3% of children. The presence of a cystic or complex adnexal mass during pregnancy is common with mature teratoma reported in approximately 30-50% of pregnancies. The ultrasound is the number one method of detection. The use of tumor markers is limited because it alters its value during pregnancy. We report a case of a 18 year old female patient who came to the General Hospital Dr. Miguel Silva in Morelia, Michoacán with a gestation age of 10.2 weeks and a recent diagnosis of an asymptomatic adnexal mass. Using the transvaginal approach, the ultrasound reported an irregular gestational sac with the absence of cardiac activity in the embryo. A diffusely echogenic adnexal mass with oval appearance, wall regularity and homogeneous internal echos of 12.96 x 8.99 cm. Exploratory laparotomy was performed finding normal uterus and ovaries, with the posterior retroperitoneal resection of the 15 cm multi-lobed tumor. The surgical specimen measured 13 x 12 x 8 cm, had a brownish color, wall irregularity, soft consistency, multi-lobed, and a yellowish interior greasy material. Microscopically the tumor is delimited with a firm capsule composed of a hyaline-fibrous tissue, lined by squamous keratinized epithelium, with multiple layers of keratin. This anato-pathologic finding is diagnostic of retroperitoneum mature teratoma.
authors.forename: Ana Norma Gricelda
authors.initials: AN
authors.lastname: Becerril-González
authors.forename: Andrés
authors.initials: A
authors.lastname: Pérez-Martínez
authors.forename: José Antonio
authors.initials: JA
authors.lastname: Sereno-Coló
mesh_terms: D000293:Adolescent; D005260:Female; D006801:Humans; D007813:Laparotomy; D011247:Pregnancy; D011252:Pregnancy Complications, Neoplastic / Q000175:diagnosis / Q000473:pathology*; D012186:Retroperitoneal Neoplasms / Q000175:diagnosis / Q000473:pathology*; D013724:Teratoma / Q000175:diagnosis / Q000473:pathology*