Sinusoidal dilatation and congestion in liver biopsy: Is it always due to venous outflow impairment?

Context.-Impairment of venous outflow manifests as zone 3 sinusoidal dilatation and congestion (SDC) in liver biopsy. However, the finding of SDC is not specific for venous outflow impairment. Objectives.-To determine the specificity of SDC in liver biopsies for venous outflow impairment and to seek an explanation for SDC in patients without clinical or radiologic features of venous outflow impairment. Design.-Liver biopsies from 51 patients with sinusoidal dilatation were reviewed. Biopsies from transplant recipients, patients with cirrhosis, and patients with hepatic neoplasms (primary or metastatic) were not included. Clinical records were reviewed for laboratory tests and final clinicopathologic diagnosis. Results.-Thirty-four patients (66.7%) had confirmed venous outflow impairment. Of the 17 cases (33.3%) without clinical and/or radiologic evidence of venous outflow impairment, vascular causes were present in 5 cases (9.8%; nodular regenerative hyperplasia in 2 cases and portal vein thrombosis, congenital absence of the portal vein, and sickle cell anemia in 1 case each). Systemic inflammatory disorders were identified in 6 patients (11.8%). These included 2 cases of Castleman disease and 1 each of sarcoidosis, Crohn disease, rheumatoid arthritis, and Still disease. Three patients (5.9%) had tumors without direct involvement of the liver (1 case each of Hodgkin lymphoma, renal cell carcinoma, and pancreatic serous pseudopapillary tumor). In the remaining 3 patients, SDC was identified in wedge liver biopsies performed at the time of surgery, including gastric bypass surgery, cholecystectomy, and splenectomy. No other disease association was apparent in these cases. Conclusion.-Sinusoidal dilatation and congestion in liver biopsy is associated with venous outflow impairment in two thirds of the cases. In the absence of clinical and/or radiological evidence of venous outflow, diagnostic considerations include other vascular conditions, such as portal vein insufficiency and nodular regenerative hyperplasia. Sinusoidal dilatation and congestion can also occur in the setting of systemic inflammatory diseases, granulomatous disorders, and neoplasms, as well as in wedge biopsies obtained during abdominal surgery.