Abstract
A 39-year-old primiparous Japanese female was admitted to the obstetrical emergency department of our hospital because of respiratory distress resulting from a large amount of pleural effusion, soon after a caesarean delivery (CD) at another hospital. While she was undergoing the CD, a giant ovarian tumour was identified. However, the tumour could not be removed at that facility and she was transferred to our hospital. Three days after the CD, a left salpingo-oophorectomy was performed with the purpose of controlling pleural and peritoneal effusions. Based on her past treatment history and the information gathered from this surgery, recurrence of ovarian cancer was considered the final diagnosis. Earlier, at the age of 37 years, she had been diagnosed with stage IC ovarian adenocarcinoma arising from a mature cystic teratoma detected after a right salpingo-oophorectomy. These kinds of situations of accidental detection of recurrent advanced ovarian cancer in a newly pregnant patient in the emergency department are rare. Amongst them, we have identified an extremely rare case showing placental metastasis. The important lesson learnt from this case report is that detailed medical interviews and physical examinations are crucial when a pregnant woman visits a hospital without a letter of referral, especially in the third trimester of pregnancy.