Note from 04.09.2015
This is a spontaneous rupture of the extremely enlarged spleen. The patient could not recall if a minor trauma was present. Spontaneous ruptures are extremely rare and there is little literature. Causes may include: Mononucleosis, splenic tumors, eg. malignant lymphomas and angioma, or the portal vein thrombosis.
For more information: The case has been discussed on DocCheck Ask!