Effect of Copper Staining in Wilson Disease: A Liver Explant Study.

ABSTRACT

OBJECTIVES: Wilson disease is a rare genetic disease with clinical and histopathologic differential diagnostic challenges. In this study, we evaluated the histopathologic findings of explanted livers in Wilson disease, with special emphasis on copper histochemistry. MATERIALS AND METHODS: Our study group was recruited by reviewing archived histopathology reports and the liver transplant clinic patient records retrospectively for patients who had liver transplant for Wilson disease between January 2010 and June 2015, at Turgut Ozal Medical Center. Archival slides were reevaluated. When needed, relevant clinical and laboratory data were obtained from patient medical records. RESULTS: During the selected period, there were 33 patients fitting the study criteria (22 male, 11 female, mean age of 22 ± 11 y). All patients had mild to moderate septal inflammation. We found that 29 patients (88%) showed glycogenated hepatocyte nuclei and 27 patients (79%) showed nuclear pleomorphism. Other histopathologic findings were cholestasis (48%) and macrovesicular steatosis (39%). There was no special finding in hilar regions except for 2 patients who had recanalized portal vein thrombosis. In terms of copper histochemistry, 2 copper stains, Timm silver sulfide and rhodanine, were performed in all cases, with orcein staining only done for 25 of the cases. Positivity rates for these copper stains were 85%, 82%, and 36%. Periodic acid-Schiff-diastase- and periodic acid-Schiff-positive granules were detected in 7 of 33 patients (21%). Iron deposition was seen in 12 patients (focal and/or minimal in 11, more than focal in 1). There was no dysplasia or malignancy in any of the patients. CONCLUSIONS: On routine hematoxylin and eosin-stained slides, detection of glycogenated hepatocyte nuclei and the finding of the nuclear pleomorphism should alert the pathologist for the possibility of Wilson disease, especially with cryptogenic liver disease. Timm stain is a more convenient histochemical stain in revealing copper deposition in liver.