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. Eventually, in the absence of another cause for spontaneous hemothorax, on either clinical or imaging grounds, we diagnosed spontaneous arteriovenous malformation. Its management is discussed herein.