Accuracy of Determining Hepatocellular Carcinoma (HCC) Tumor Grade on Core Needle Biopsy (CNB)
A Manuyakorn, AC Lowe, S Sabounchi, D Lu, CR Lassman. UCLA, Los Angeles; Siriraj Hospital, Bangkok, Thailand
Background: Low grade and well differentiated HCC have been demonstrated to have better prognosis than high grade/poorly differentiated HCC after resection. Accordingly, it has been suggested that results of CNB be taken into account when considering transplantation of patients with HCC who exceed Milan criteria. This study aims to assess the validity of tumor grade assessment by CNB.
Design: After IRB approval, 344 patients with histology proven HCC were identified at a single institution. CNB and resection material (hepatectomy or resection) was available for review in 40 patients. Two pathologists determined tumor differentiation with agreement by double-headed scope. Well differentiated (WD) was defined as AFIP nuclear grade 1 or grade 2 with a trabecular or acinar pattern, moderately differentiated (MD) as nuclear grade 3 or grade 2 with solid or schirrous pattern, and poorly differentiated as nuclear grade 4.
Results: The 40 patients included 31 men and 9 women, with a mean age of 57 years (range 33-74). Interval time between CNB and resection was <6 months in 24 patients and >6 months in 16. Fifteen cases had a single lesion and 25 had multiple lesions. Thirty patients received preoperative treatment; 10 did not. Concordance of tumor differentiation between CNB and resection was poor (Table 1) with Kappa of - 0.009 (p 0.5384), with CNB underestimating tumor differentiation in resection material in 19 cases, demonstrating the same differentiation in 17, and overestimating in 4. When only nuclear grade was considered, CNB underestimated the resection material in 23 cases, showed the same grade in 14, and overestimated in 3. Concordance was also poor when interval time, number of lesions, and preoperative treatment were considered.