Aim: Our aim was to demonstrate the diagnostic difficulties as well as the atypical clinical development of ovarian tumours in combination with pregnancy.
Material and methods: We present a rare case of large mucinous cystadenoma in 32-year old patient, who is 20 gestational weeks pregnant. Ultrasound examination and MRI were performed, which visualized a huge multilocular ovarian tumour formation with a small amount of ascites.
Results: We performed laparatomy adnexectomy which included the ovarian cyst, partial omentectomy and we took 4 samples of smears from the whole abdominal cavity, as well as ascites samples for cytology. The pregnancy was preserved. The histological examinations reported: mucinous cystadenoma without morphological data for malignant transformation.
Conclusions: In our rare case the organ preserving operation was a completely sufficient surgical staging procedure.