Variations in appearance of endometriomas

Objective. Because of the range of patient ages with endometriosis, the persistence of endometriomas, and the degradation of internal blood products over time, the appearance of endometriomas is variable. The purpose of this study was to identify the prospective diagnoses in cases of surgically proven endometriomas and to illustrate the variety of appearances of endometriomas. Methods. Sonographic images from 325 women with histologic confirmation of an adnexal mass during a 16-month period were reviewed. Eighty-seven endometriomas in 71 women were found. Prospective diagnoses were scored as follows: 1, the diagnosis was endometrioma only; 2, the differential diagnosis listed endometrioma first; 3, the differential diagnosis listed endometrioma but not first; 4, the diagnosis did not include endometrioma but included a complex or hemorrhagic cyst; and 5, the diagnosis did not include endometrioma. Lesions with the classic appearance of an endometrioma (hypoechoic mass with diffuse low-level internal echoes) or an atypical appearance were chosen for illustration. Results. Thirty-five (60.3%) of 58 endometriomas measuring at least 2 cm in greatest dimension included endometrioma in the differential diagnosis at sonography. In 6 (10.3%) of 58, the lesions were described as complex or hemorrhagic cysts. Atypical endometriomas included cases with retracted clots that appeared solid but without blood flow, endometriomas in pregnant patients, and endometriomas in postmenopausal women with heterogeneous internal echoes and central calcification. A ruptured endometrioma was interpreted as pelvic inflammatory disease. Five endometriomas were suspected to be malignancies because of a solid appearance, blood flow, surrounding adhesions, and, in 1 pregnant patient, extensive decidualization. Conclusions. Recognition of the varied appearance of endometriomas should aid the interpreting physician in giving an appropriate prospective diagnosis of endometriomas.