Mature cystic teratoma of the uterus presenting as an endometrial polyp

Mature cystic teratomas (MCTs) (commonly called ‘dermoid cysts’) are cystic tumors composed of well-differentiated tissue derived from at least two of the three germ cell layers (ectoderm, mesoderm and endoderm). They usually arise in the ovaries but can be extragonadal, with uterine location exceedingly rare.

We describe the sonographic features of an MCT presenting as an endometrial polyp in a 58-year-old asymptomatic woman, referred to our division after a 15-mm polyp was found following routine transvaginal ultrasound examination. Imaging was performed using a Siemens Aldara machine (Germany) with a 7.5-MHz convex transducer (Figure 1). The polyp was excised hysteroscopically and had a fibrous consistency, appearing as a 3 × 1-cm benign mucosal polyp with a smooth surface. Final pathology confirmed the diagnosis of MCT