Just an Acute Pulmonary Edema? Paraneoplastic Thyroid Storm Due to Invasive Mole

Hydatidiform mole is a malignant entity included in the gestational trophoblastic diseases. It usually produces pregnancy hormones such as beta-human chorionic gonadotropin (β-hCG), which in turn stimulates endogenous thyroid hormone production. We report the case of a high-risk complete invasive hydatidiform mole with pulmonary metastasis and associated paraneoplastic syndrome. The patient is a 30-year-old woman who presented symptoms of pregnancy and metrorrhagia. A uterine mass was detected. Urine β-hCG was found negative. In serum, 2,662,000 mIU/mL (normal range: <5) was found, together with parameters of severe hyperthyroidism. The patient underwent uterine curettage with diagnostic and therapeutic means. At that precise moment, her pregnancy-like symptoms worsened and she developed restlessness, tachycardia, diaphoresis, dyspnea at rest, and peripheral edema. A scan showed bilateral pulmonary nodules suggestive of metastasis, acute pulmonary edema, and bilateral pleural effusion without signs of pulmonary thromboembolism. At that time, she presented a free T4 of 2.34 ng/dL (normal range: 0.8-1.8 ng/dL), causing a thyroid storm with secondary cardiac dysfunction. The patient was treated with corticosteroid therapy to decrease peripheral conversion of thyroid hormone T4 to active T3. Her symptoms remitted within 8 h. After 48 h, T4 level was 1.2 ng/dL while serum β-hCG was 80,000 mIU/mL, with a positive urine result. The change in the urine analysis is due to the "hook effect" of the reactive test. An effective chemotherapy treatment was started according to the EMA-CO scheme, remaining free of disease at present. Knowing paraneoplastic syndromes is necessary to achieve the best clinical management and to start treatment early.