# Experience with hepatectomy in a patient with focal nodular hyperplasia combining with constitutional indocyanine green excretory defect: a case report

## TL;DR

A patient with a rare liver condition successfully underwent liver surgery despite abnormal test results, highlighting the need for comprehensive evaluations.

## Contribution

This case demonstrates that ICG clearance alone is insufficient for assessing liver function in patients with constitutional ICG excretory defect.

## Key findings

- The patient had a normal liver function despite a high ICG-R15 score.
- Hepatic resection was safely performed with no postoperative complications.
- The case emphasizes the need for multifaceted preoperative evaluations in similar patients.

## Abstract

This report details the first documented instance of successful hepatic resection performed in a patient presenting with focal nodular hyperplasia (FNH) concomitant with constitutional indocyanine green (ICG) excretory defect – an exceptionally rare hepatic transport disorder initially characterized in 1974. A male patient in his early 20s was diagnosed with FNH necessitating surgical evaluation. Preoperative assessment revealed a profoundly elevated ICG retention rate at 15 min (ICG-R15) of 66.7%, indicating severely impaired clearance based on conventional interpretation. Crucially, however, comprehensive evaluation demonstrated discordantly normal standard liver function biochemical parameters (including bilirubin, transaminases, albumin, coagulation profile) and entirely unremarkable histopathological findings obtained via percutaneous biopsy of radiologically normal liver parenchyma. This definitive constellation of findings confirmed the diagnosis of constitutional ICG excretory defect, effectively excluding intrinsic hepatic parenchymal dysfunction or significant functional impairment. Consequently, proceeding with hepatic mass resection was deemed justified. The surgical intervention and immediate postoperative course were entirely uneventful, characterized by hemodynamic stability, absence of biochemical liver failure, and no complications during the critical recovery phase, with histopathology confirming FNH. This case constitutes a seminal demonstration that ICG clearance kinetics are inherently unreliable and potentially misleading as a sole indicator of functional hepatic reserve in patients harboring this specific excretory defect who are candidates for hepatectomy. Our findings establish the critical principle that the imperative for a multifaceted preoperative evaluation strategy that transcends reliance on ICG kinetics alone to safely guide surgical intervention in this unique patient population.