Features of Wunderlich's syndrome:
(1) The key feature is spontaneous (nontraumatic) retroperitoneal hemorrhage.
(2) Most patients present with Lenk's triad (see above).
(3) The hemorrhage arises from one or both kidneys.
Renal tumors associated with Wunderlich's syndrome:
(1) renal angiomyolipoma
(2) renal cell carcinoma
(3) leiomyosarcoma
(4) other benign or malignant renal tumor
Vascular lesions associated with Wunderlich's syndrome:
(1) vasculitis (polyarteritis nodosa, Wegener's granulomatosis, etc)
(2) arterial aneurysm
(3) arteriovenous malformations
(4) venous thrombosis
(5) segmental arterial mediolysis
Other causes of Wunderlich's syndrome:
(1) coagulopathy, including excessive anticoagulation
(2) renal cystic disease
(3) renal infection
(4) calculus disease
