MRI characteristics of primary fallopian tube choriocarcinoma: a case report

Abstract

Tubal choriocarcinoma is uncommon, and its magnetic resonance imaging characteristics have not yet been reported. In this report, a 39-year-old woman presented with irregular painless vaginal bleeding and a palpable left lower abdominal lump for 2 months following 6 weeks' amenorrhea and positive urine pregnancy test. Her serum β-human chorionic gonadotropin value was significantly increased. Ultrasound revealed a left adnexal mass, which showed no blood flow signal on Color doppler flow imaging. A further MR examination showed a well-defined cystic-solid mass with cystic component accounting for a large proportion in the left lower abdomen. The solid part with mixed signals resembled a honeycomb. Finally, the left tubal choriocarcinoma was confirmed by pathology. When the solid parts of cystic-solid mass appeared as "honeycomb appearance" and the ovaries were normal by magnetic resonance imaging, together with typical symptoms and significantly elevated β-human chorionic gonadotropin values, radiologists should feel more confident in suspecting tubal choriocarcinoma and reporting it on their differential.

Keywords: Choriocarcinoma; Fallopian tube; MRI.

Fig. 1

A cystic-solid mass in the left adnexal region detected by ultrasound.

Fig. 2

(A and B) T1WI and T2WI detected that a round-like solid cystic mass with sharp margin was located at the left lower abdomen, and nodular protrusion and solid portion were attached to the capsule wall. Solid component resembled “honeycomb.” (C and D) T2WI detected that the similar left ovarian signal and the left uterine horn were pulled by the mass to upper left direction. (E) a partial solid component of the mass showed apparent diffusion limited slightly.

Fig. 3

(A and B) CT detected the left lung subpleural nodule and right pulmonary nodule before operation and chemotherapy. (C) The size and density of right pulmonary nodule decreased before the second course of chemotherapy. (D and E) The size of nodule in right pulmonary lower lobe increased, and a new nodule appeared on the upper lobe of the right lung.

Fig. 4

Microscopic findings: syncytiotrophoblast and cytotrophoblast amidst extensive areas of hemorrhage and necrosis (H-E stain, ×200).

Fig. 5

Immunohistochemical findings: the cytoplasm of syncytiotrophoblastic cell was strong positive in the HCG (cytoplasmic staining). HCG, human chorionic gonadotropin.