erm cell tumors are most commonly located within the gonads.1 Rare extragonadal locations of these tumors include the retroperitoneum, mediastinum, sacrococcygeum, and central nervous system and are considered to result from aberrant migration of germ cells from the yolk sac during fetal development. [1][2][3][4] We present transvaginal sonographic and magnetic resonance imaging (MRI) findings of a massive epidermoid cyst extending from the pelvis to the buttock.
Case ReportA 28-year-old woman, para 1, presented with gluteal pain exacerbated during sitting and walking. Other than endometriosis confirmed by laparoscopy after secondary dysmenorrhea 7 years before her current presentation, her history was unremarkable. On physical examination, the patient was in no acute distress. Vital signs were normal, and her abdomen was soft and nontender. Pelvic examination disclosed a normal-sized uterus and adnexa. A symmetric soft pelvic mass approximately 6 cm in diameter was noted posterior to the uterus. A large cystic mass measuring approximately 10 cm in diameter bulging into the medial aspect of the right buttock was noted.Transvaginal sonography depicted a retroverted uterus with normal ovaries (the right containing a hemorrhagic cyst). A large heterogeneous mass located posterior to the uterus was noted (Figures 1 and 2). The patient was offered yet declined sonography of the right buttock. Magnetic resonance imaging delineated a pelvic mass with a large extrapelvic extension protruding to the medial aspect of the right buttock (Figure 3).