Patterns of Misinterpretation of Adnexal Masses on CT and MR in an Academic Radiology Department

A 45-year-old woman with colon cancer. Axial pelvic contrast-enhanced computed tomographic image, showing a simple-appearing right adnexal cyst with slightly thickened hyperattenuating wall (arrow). This was called a physiologic cyst, which was reasonable, because simple adnexal cysts are so common. However, the histologic diagnosis was metastatic colon cancer. This case was not ultimately categorized as a quality assurance case, because the primary reviewer flagged the case because of the missed diagnosis of malignancy, but all three reviewers felt that this could not be prospectively determined to be abnormal.

A 51-year-old woman with elevated liver function test results. (a) Coronal true fast imaging with steady-state precession (repetition time, 3.3 ms; echo time, 1.6 ms; matrix size, 256 × 256; slice thickness, 10 mm) magnetic resonance scout image and (b) coronal half-Fourier acquisition single-shot turbo spin-echo image (repetition time, 911 ms; echo time, 76 ms; matrix size, 256 × 205; slice thickness, 5 mm) show a 4.4-cm left adnexal cyst (arrow in a), which was not mentioned in the report. There is a single thin septation (arrowhead in b). The histologic diagnosis was serous cystadenoma.

A 77-year-old woman with a gastrointestinal stromal tumor. Axial contrast-enhanced computed tomographic image shows a 5-cm right adnexal mass (arrow) with calcifications, which was not mentioned in the computed tomographic report. The histologic diagnosis was metastatic gastrointestinal stromal tumor.

A 51-year-old woman with gluteal pain. Axial T1-weighted spin-echo (repetition time, 910 ms; echo time, 14 ms; matrix size, 512 × 512; slice thickness, 5 mm) magnetic resonance (a) and axial contrast-enhanced computed tomographic (b) images show a 4-cm fat-containing lesion (arrows), consistent with an ovarian dermoid, which was confirmed on histopathologic analysis. This lesion was not mentioned in either imaging report.

A 48-year-old woman with abdominal pain and fever. Axial contrast-enhanced computed tomographic image shows a lobulated mass or two adjacent heterogeneous pelvic masses, one of which was called an exophytic fibroid and the other of which was thought to be the uterus, as well as a third right adnexal mass (arrows). The ovaries were not visualized. Histologic diagnosis was papillary serous carcinoma (metastatic).

A 39-year-old woman with left flank pain and hydronephrosis. Axial computed tomographic images from two separate exams, 3 months apart, of an 8-cm, heterogeneous, eccentric pelvic mass (arrows), which was new since 5 years previously. On both exams, this was called a fibroid, but the histologic diagnosis was lymphoma.

A 34-year-old woman at 20-week gestational age with an adnexal cyst seen on obstetric ultrasound. (a) Axial T2-weighted single-shot fast spin-echo (repetition time [TR], 727 ms; echo time [TE], 60 ms; matrix size, 256 × 160; slice thickness, 4 mm) magnetic resonance image shows an 8.5-cm right adnexal cyst with a small mural nodule (arrow) anteriorly. Axial gradient-echo (GRE) T1-weighted in-phase image (b) (TR, 205 ms; TE, 4.4 ms; matrix size, 256 × 160; slice thickness, 5 mm) shows high signal intensity in the nodule (arrow) compared to the low–signal intensity fluid in the cyst. Because of the loss of signal intensity within the nodule (arrow) on the T1-weighted opposed phase (TR, 205 ms; TE, 2.2 ms; matrix size, 256 × 160; slice thickness, 5 mm) (c) and fat-saturated GRE (TR, 180 ms; TE, 4.2 ms; matrix size, 256 × 160; slice thickness, 5 mm) (d) images, this cyst was called a dermoid. However, no fat was identified histologically, and the final diagnosis was epidermoid cyst.

A 55-year-old woman with left lower quadrant pain. Axial contrast-enhanced computed tomographic image shows 4.5-cm and 3.8-cm adnexal masses (arrows). The report recommended further characterization by ultrasound “if clinically indicated,” but the ultrasound was not performed until 15 months later. In a postmenopausal patient, these findings are concerning, and an ultrasound is indicated on the basis of the imaging findings. No clinical correlation is needed. The histologic diagnosis was serous cysts.