Introduction/Objective
Spontaneous renal hemorrhage is a rare complication of various kidney pathologies. It can be due to renal artery aneurysms, arteriovenous malformations, cystic renal diseases, renal calculus, coagulation disorders, as well as neoplastic lesions like angiomyolipoma and renal cell carcinoma (RCC). Individuals present with sudden flank or scapular pain, hypovolemic shock, termed as Wunderlich syndrome (WS). 30-35% cases of WS are from spontaneously ruptured RCC, commonly clear cell variant (70%) followed by papillary (10-15%) and chromophobe variant (4-6%). We present an autopsy case of a papillary variant RCC identified as a small kidney mass with a pathogenetic correlation behind the intractable bleeding.
Methods/Case Report
An 81-year-old Caucasian man with a history of atrial fibrillation, on long-term Xarelto treatment, was found to have a 1.2 cm incidental mass in the right kidney. He started experiencing right-sided scapular pain, then rapidly became hypotensive, drowsy. CT scan revealed a large right-sided perinephric and retroperitoneal hematoma (17.5 x 5.7 x 8.9 cm) extending in the pelvis. Despite receiving blood products, other supportive treatment, and successful angio-embolization, his condition worsened to acute kidney injury, bowel ischemia, and persistent lactic acidosis leading to death. On autopsy, bloody ascites, clots on mesenteric root insertion, and bulging in retroperitoneal spaces were seen. The perinephric spaces had organized clots. The bleeding originated from a 2.0 x 2.0 cm brown mass in the middle pole of the right kidney. There was a slit-like vessel at the interface of the kidney and the mass. Microscopic examination of the mass shows trabecula of abnormal cells with abundant eosinophilic cytoplasm in the hemorrhagic and necrotic background. These cells are positive for PAX8, CK7, CD10, dim positive for CAIX, and negative for CD117, which is consistent with renal cell carcinoma, papillary variant.
Results (if a Case Study enter NA)
NA.
Conclusion
Papillary RCC is much less vascular and less aggressive than clear cell RCC. However, necrosis or bleeding into renal vessels may occur. In this case, blood-leaks and accumulation in enclosed space followed by necrosis, fibrosis, and hyalinization cause neovascularization forming a negative spiral for re-bleeding. Anticoagulants can lead to profuse sustained bleeding from even very small size RCC.
