Left kidney mass and retroperitoneal extension, suspect hemangiosarcoma or similar neoplasia. Free fluid, consistent with hemoabdomen. A surgical consult can also be considered; however, blood transfusion is essential in this case. No overt evidence of metastatic disease was noted. It is possible that this may be represent a blood clot; however, it appears to be too coarse, too organized and deriving from the caudal pole of the left kidney.
Echocardiogram and chest radiographs are recommended. The coagulopathy in this case could be primary or secondary owing to consumptive disease from subacute bleeding over the last number of days from the renal mass. The mass will merit surgical resection regardless. Blood transfusion and plasma transfusions will be necessary in this patient to stabilize bleeding.