Asian Journal of Case Reports in Surgery

Background: The incidence of symptomatic focal nodular hyperplasia (FNH) is 0.03%. FNH has female predominance that accounts for 90% of cases. It is a hypervascular benign liver tumor and is sometimes difficult to diagnose if there is a lack of typical findings on imaging. In the management of FNH, guidelines recommend conservative treatment rather than surgical resection.

Case report: An elderly male presented with abdominal fullness, anorexia, and weight loss with absence of jaundice and fever. The patient underwent percutaneous biopsy that was inconclusive. Subsequent imaging showed regression of tumor demonstrated by 3D liver volumetric assessment with a 92.3% decrease in tumor volume. The patient underwent extended right hepatectomy with total caudate lobectomy. The postoperative period was uneventful and the patient was discharged on postoperative day 8. Histopathological examination of the surgical specimen confirmed the diagnosis of FNH.

Conclusion: Spontaneous regression of FNH in male patients over a 3-month period is rare. The injury due to the core needle biopsy was possibly the mechanism that resulted in vascular thrombosis with subsequent regression and secondary immune reaction. To the best of our knowledge, this is the first case report using a 3D liver volumetric regression evaluation, which demonstrated its feasibility and usefulness in the planning of complex liver surgery.