Tubal ectopic pregnancy. A 24-year-old female with abdominal pain. Gray scale transabdominal US shows a complex-appearing, mostly solid left adnexal mass with mild internal vascularization on color Doppler US examination (arrows). Serum beta-hCG level was found to be mildly elevated (1120 mIU/mL). Imaging findings suggestive of ectopic pregnancy and she was placed on methotrexate treatment. Serial follow-up US exams did not demonstrate any decrease in size and her serum beta-hCG level remained persistently elevated between 1000 and 2000 mIU/mL. The lack of response to medical treatment prompted surgical removal of the mass which finally confirmed ectopic pregnancy with no histopathological evidence of neoplastic or inflammatory disease