[The magnetic resonance and histological correlations in hepatocellular carcinoma]

Hepatocellular carcinoma (HCC) exhibits variable features on Magnetic Resonance (MR) images. In this study, the correlations between MR patterns of HCC and histopathologic findings are investigated. Fifty patients with HCCs were studied with MR at 0.5 T. All neoplastic lesions were subsequently submitted to biopsy: structural pattern, tumor grading (following the Edmonson and Steiner classification), the presence of fatty degeneration, and intracellular glycogenic content (established on the basis of staining by the periodic acid Schiff-PAS-method) were evaluated. Thirteen HCCs were < 3 cm, 16 ranged 3-5 cm, and 21 were > 5 cm. On spin echo (SE) T1-weighted images (T1w), 18 tumors were hyperintense, 10 isointense, and 22 hypointense with respect to the surrounding liver parenchyma. On SE T2-weighted images (T2w), 46 HCCs resulted hyperintense and 4 isointense. Histopathologic examination demonstrated 46 tumors with trabecular pattern and 4 tumors with pseudoglandular pattern; however, no significant correlation between structural pattern and signal intensity was observed. Thirty-one HCCs were classified as well-differentiated tumors (grade 1), 12 as moderately differentiated tumors (grade 2), and 7 as poorly-differentiated tumors (grade 3). Hyperintensity on SE T1w and isointensity on SE T2w significantly correlated with grade 1 tumors (p < 0.01). No MR feature demonstrated significant correlation with grade 2 or grade 3 tumors. Fatty degeneration was demonstrated in 4 HCCs: none of them resulted hyperintense on SE T1w (2 were isointense and 2 hypointense). PAS staining was strongly positive in 16 lesions, slightly positive in 20 and negative in 14 lesions. Strong positive staining by the PAS method significantly correlated with hyperintensity on SE T1w (p < 0.01). Hyperintensity on SE T1w and isointensity on SE T2w strongly suggest well-differentiated HCCs. High signal intensity on SE T1w correlates with high glycogenic content of the tumor cells and seems unaffected by the presence of fatty degeneration.