Noninvasive imaging techniques, such as dynamic computed tomography (CT), magnetic resonance imaging and transabdominal ultrasonography are limited in their ability to detect hepatic lesions less than one cm. Intraoperative ultrasonography (IOUS) is currently the most sensitive modality for the detection of small hepatic lesions. However, IOUS is invasive requiring laparoscopy or formal laparotomy. We sought to evaluate the feasibility of using endoscopic ultrasonograhpy (EUS) for the detection and diagnosis of hepatic masses in patients with hepatocellular cancer (HCCA) and metastatic lesions (ML). We hypothesized that EUS could detect small (<1.0 cm) hepatic lesions undetectable by CT scan and could be used for biopsy of deep-seated hepatic lesions.

Consecutive patients referred for EUS with suspected liver lesions were evaluated between July 2000 and October 2001. All patients underwent EUS using an Olympus (EM30) radial echoendoscope. If liver lesions were confirmed and fine needle aspiration (FNA) was deemed necessary, a linear array scope was used and an FNA performed with a 22-gauge needle. Two passes were made for each lesion.

14 patients underwent evaluation with dynamic CT scans and EUS. In all 14 patients, EUS successfully identified hepatic lesions ranging in size from 0.3 cm to 14 cm (right lobe: n = 3, left lobe: n = 1, bilobar: n = 8). Moreover, EUS identified new or additional lesions in 28% (4 of 14) of the patients, all less than 0.5 cm in size (HCCA: n = 2, ML: n = 2), influencing the clinical management. In 2 of 14 patients EUS identified liver lesions, previously described as suspicious by CT scan, to be hemangiomas. Nine patients underwent EUS-guided FNA of hepatic lesions (deep seated: n = 3, superficial: n = 6). All FNA passes yielded adequate specimens (malignant: n = 8, benign: n = 1).

Our preliminary experience suggests that EUS is a feasible preoperative staging tool for liver masses suspected to be HCCA or metastatic lesions. EUS can detect small hepatic lesions previously undetected by dynamic CT scans. Furthermore, EUS-guided FNA can confirm additional HCCA liver lesions or liver metastases, in deep-seated locations, upstaging patients and changing clinical management.