Massive spontaneous hemothorax during the immediate postpartum period.

Nontraumatic hemothorax is a rare cause of postpartum respiratory distress. We present a case of massive spontaneous hemothorax, which presented during the immediate postpartum period and was initially treated as pulmonary embolism. Further investigation revealed a tiny lung nodule: although pulmonary arteriovenous malformation was considered, the imaging appearances tended to counter this interpretation.