IS Case 107: Paroxysmal nocturnal hemoglobinuria deposits in renal cortex

Scott Mooney, MD

Imaging Sciences URMC 2008
Publication Date: 2009-05-20

History

Patient is a 69-year-old female with a 3 month history of intermittent right upper quadrant pain. Clinical suspicion of biliary disease or stones. Patient has history of anemia thought to be due to paroxysmal nocturnal hemoglobinuria.

Findings

Renal cortex has decreased signal on all sequences without contrast enhancement. The liver, spleen, and pancreas demonstrate normal signal intensity.

Diagnosis

Paroxysmal nocturnal hemoglobinuria deposits in renal cortex

Discussion

Paroxysmal nocturnal hemoglobinuria (PNH) is a complement-mediated intravascular hemolysis, which can result in bleeding, thrombosis, hemoglobinuria, and iron deficiency anemia. The Ham's serum test is used for diagnosis.

After the blood cells are destroyed, hemosiderin deposits in epithelial cells of the proximal convoluted tubules within the renal cortex. Patients can develop chronic renal failure from PNH, which is due to microvascular thrombosis and not the hemosiderin deposition.

Typical MR findings in PNH include a reversal of the normal cortex-medulla differentiation on T1-weighted images, with the cortex darker than the medulla due to the paramagnetic effect of the hemosiderin. T2-weighted images also demonstrate low--signal intensity due to the iron deposition. Other processes with result in intravascular destruction of blood cells, such as sickle-cell disease and cardiac valve hemolysis, are less common causes for hemosiderin deposition in the renal cortex. The liver and spleen usually do not show increased iron uptake unless the patient has received numerous blood transfusions for anemia.

References

  1. Jeong JY, Kim SH, Lee HJ, Sim JS. typical low-signal-intensity renal parenchyma: causes and patterns. Radiographics. 2002 Jul-Aug;22(4):833-46. [PMID: 12110713]
  2. Mulopulos GP, Turner DA, Schwartz MM, Murakami ME, Clark JW. MRI of the kidneys in paroxysmal nocturnal hemoglobinuria. AJR Am J Roentgenol. 1986 Jan;146(1):51-2. [PMID: 3484409]
  3. Rimola J, Martín J, Puig J, Darnell A, Massuet A. The kidney in paroxysmal nocturnal haemoglobinuria: MRI findings. Br J Radiol. 2004 Nov;77(923):953-6. [PMID: 15507422]

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