Needle tract implantation of hepatocellular carcinoma after percutaneous ethanol injection

BACKGROUND. Percutaneous ethanol injection (PEI) therapy currently is widely used for small hepatocellular carcinoma (HCC). However, only limited information is available regarding needle tract implantation after PEI treatment. METHODS. Records of HCC patients who underwent PEI between March 1990 and April 1997 at the National Cancer Center Hospital (n = 177) were reviewed to clarify the incidence, risk factors, and outcome of needle tract implantation of HCC. RESULTS. PEI was performed for 348 HCC patients with a median tumor size of 20 mm. Needle tract implantation was found in 4 patients (10, 13, 15, and 46 months, respectively, after PEI). The size of the PEI- treated HCC tumors in these patients was 20, 27, 28, and 30 mm, respectively, in greatest dimension. All tumors were enhanced in the early phase on dynamic computed tomography (CT), and were found to have moderate tumor cell differentiation on biopsied specimens. Of the four implanted tumors, three were resected and the remaining tumor was treated with extrabeam radiotherapy. At last follow-up, 2 of the 4 patients had died (1 of variceal bleeding 60 months after PEI and the other from cancer 61 moths after PEI) and 2 were still alive (14 and 20 months, respectively, after PEI) with no evidence of active tumor. CONCLUSIONS. Needle tract implantation after PEI is not unusual, especially when HCC tumors are ≤2 cm in greatest dimension, enhanced in the early phase on dynamic CT, and/or moderately differentiated on biopsied specimens.