Abnormal Liver Stiffness Measurement in a Patient with Waldenstrom Macroglobulinemia: Nuances in Interpreting the Findings

Abstract

Background: Liver stiffness measurement (LSM) using vibration-controlled transient elastography (VCTE) provides an estimate of liver fibrosis, non-invasively, in a quick and efficient manner. Its use and interpretation of LSM is limited. In the current case, we report our findings of abnormal LSM and liver histology in a patient with Waldenstrom Macroglobulineima (WM) with evidence of portal hypertension. Case: A 84-year-old white man with history notable for WM and history of pulmonary embolism on chronic anticoagulation presented with new-onset ascites. His blood work revealed isolated elevation in alkaline phosphatase (AST 14 U/L, ALT 7 U/L, ALP 173 U/L, GGT 275 u/L and total bilirubin 0.6 mg/dL) with a platelet count was 208 k/cumm. Blood work for competing etiology was negative for viral, metabolic, and autoimmune hepatitis (negative viral hepatitides, normal iron studies, normal alpha-1-antitrypsin level, negative anti-smooth muscle antibody and negative anti-mitochondrial antibody with normal immunoglobulins (other than presence of IgM kappa monoclonal protein) ruling out primary biliary cirrhosis). Ultrasound with dopplers showed cirrhotic appearing liver, cholelithiasis, mild ascites not amenable to diagnostic paracentesis, and patent portal veins. MRCP showed normal appearing liver, mild ascites, and gallbladder sludge without biliary dilation. Evaluation with VCTE after paracentesis revealed elevated LSM at 12.2 with IQR% of 9%. Pressure measurements during transjugular liver biopsy noted normal hepatic vein pressure gradient (HVPG) of 6 mmHg (corrected sinusoidal pressure 10 mmHg (RA 1 mmHg, IVC 5 mmHg, free HV 5 mmHg, wedge 11 mmHg), consistent with pre-sinusoidal portal hypertension. Liver histology showed nodularity in the absence of significant fibrosis. Reticulin stain confirmed nodularity and showed areas of hepatic trabecular compression and others with trabecular thickening. Focal mild sinusoidal dilatation was seen. The portal tracts are largely unremarkable with patchy mild chronic inflammation and minimal ductular reaction. Congo red stain was negative as well ruling out amyloidosis. Conclusion: This case highlights the rare presentation of non-cirrhotic portal hypertension with WM and the false increase in LSM due to infiltration with M protein.