# A Case of Misdiagnosed Hepatic Sarcoidosis: Evaluating Ultrasound Resolution Microscopy for Differentiating Hepatic Sarcoidosis from Hepatocellular Carcinoma

## TL;DR

This case study shows how ultrasound resolution microscopy can help distinguish between hepatic sarcoidosis and hepatocellular carcinoma, which often look similar on imaging.

## Contribution

The study introduces ultrasound resolution microscopy as a novel tool for differentiating hepatic sarcoidosis from HCC based on microvascular parameters.

## Key findings

- URM revealed differences in microvascular flow velocity and diameter between hepatic sarcoidosis and HCC.
- Microvascular density ratio and vascular distribution also showed distinct patterns in the two conditions.
- URM provides quantitative data to aid in the differential diagnosis of liver lesions.

## Abstract

Background and Clinical Significance: Hepatic sarcoidosis is a benign lesion of unknown etiology. The gold standard for diagnosing hepatic sarcoidosis is histopathological examination. The symptoms and imaging findings of patients with hepatic sarcoidosis are often atypical, leading to misdiagnosis as hepatocellular carcinoma (HCC). Ultrasound resolution microscopy (URM) can overcome the diffraction limit, enabling fine visualization and quantitative analysis of the microvascular networks. This study aimed to provide new evidence for the differential diagnosis of these two diseases by comparing the URM parameters of hepatic sarcoidosis initially misdiagnosed as HCC with those of HCC. Case Presentation: A 67-year-old woman was admitted to the hospital due to upper abdominal pain for two weeks. Ultrasonography revealed a liver mass. The lesion was located in segment IV of the left hepatic lobe, was approximately 18 × 10 mm in size, and appeared hypoechoic. Contrast-enhanced ultrasound and enhanced magnetic resonance imaging both showed a “fast-in, fast-out” pattern, strongly suggesting HCC. The tumor markers were within the normal range. The patient underwent a laparoscopic left hepatic lobectomy. The histopathological diagnosis of the resected specimen was “hepatic sarcoidosis”. URM examination was performed during the preoperative diagnostic process. Subsequently, the URM parameters of the patient’s lesion were analyzed and compared with those of HCC. The results showed differences in multiple URM parameters, including microvascular flow velocity, diameter, microvascular density ratio, and vascular distribution, between this case of hepatic sarcoidosis and HCC. Conclusions: URM can quantitatively and multidimensionally evaluate the microvasculature of liver lesions, providing new reference data for the diagnosis and differential diagnosis of hepatic sarcoidosis.