Nodular Regenerative Hyperplasia: Report of 82 Patients and Systematic Review of Literature.

Background: Data about the clinical significance and outcome of patients with nodular regenerative hyperplasia are limited.

Objective: The aim of this study was to describe the clinical and histopathological characteristics of patients with nodular regenerative hyperplasia and compare our findings with the literature.

Methods: From January 2015 to March 2021, patients with a diagnosis of nodular regenerative hyperplasia were included. They were extracted from the database of the pathology department of Cliniques universitaires Saint-Luc. Clinical and histological data were retrospectively recorded and complications of portal hypertension and mortality were analyzed. We also performed a systematic review of the literature.

Results: Eighty-two histology-proven nodular regenerative hyperplasia were included. The mean age at diagnosis was 58 ± 14 years. At least one clinical sign of portal hypertension was present in 37 patients (45%), and liver tissue sampling was performed for 29 of them for evaluation of portal hypertension. Conversely, nodular regenerative hyperplasia was an incidental discovery in 27 patients (33%), mostly after liver resection for metastasis (n = 15) or protocol biopsy in liver-transplanted patients (n = 9). The 5-year liver-related mortality was 5%. The 5-year non-liver-related mortality was 20%. Patients diagnosed by clinical suspicion (n = 55) were compared to patients diagnosed incidentally (n = 27). Patients with an incidental diagnosis had more frequently a condition associated with nodular regenerative hyperplasia than patients diagnosed clinically (93% vs. 66%, p = 0.008) and they developed significantly lower liver-related complications (4% vs. 27%, p = 0.01). A systematic review allowed us to compare our patients with 10 case series in the literature.

Conclusion: The clinical spectrum of patients with nodular regenerative hyperplasia is heterogeneous, including patients with clinical liver manifestations and patients diagnosed incidentally who could remain free of liver-related complications. This suggests that nodular regenerative hyperplasia could be a histological epiphenomenon as well as a clinical entity.