Primary malignant tumor of the fallopian tube: appearance at CT and MR imaging

Primary malignancy of the fallopian tube is a rare entity. To determine the radiologic characteristics of the tumor, 10 patients with pathologically confirmed fallopian tube malignancy (nine with adenocarcinoma and one with mixed müllerian tumor) underwent magnetic resonance (MR) imaging and computed tomography (CT). With both CT and MR imaging, the lesion appeared relatively small, solid, and lobulated when not associated with hydrosalpinx. At CT, the lesion had an attenuation equal to that of other nonspecific soft-tissue masses and enhanced less than myometrium. On T1-weighted MR images the tumor was usually hypointense, and on T2-weighted images the tumor was most often homogeneously hyperintense. Associated CT and MR imaging findings were peritumoral ascites (four cases), intrauterine fluid collection (two cases), and hydrosalpinx (one case). MR findings allowed the lesion to be distinguished from uterine leiomyoma in three cases in which pelvic examination, ultrasound, and CT findings were equivocal.