Hepatocellular carcinoma. Polygonal cell type with fibrous stroma--an atypical variant with a favorable prognosis.

Hepatocellular carcinoma, even when treated with operative resection, is generally regarded as uniformly fatal. Isolated reports of an unusual histologic variant characterized by polyglonal cells with a fibrous stroma (PCFS) suggest a more favorable outcome. Twelve cases of PCFS, representing the largest reported group, are presented. The mean age of the patients at the time of onset was 23.1 years and the male to female ratio was 1:2. Successful operative resection of the primary neoplasm and metastatic foci has resulted in a significant percentage of long-term survivors with a mean survival time of 68 months and two- and five-year survival rates of 82% and 63%, respectively. The variant shows cytologic similarity to differentiated hepatocellular carcinoma with a unique stromal appearance suggesting a pattern of fibrosis associated with focal nodular hyperplasia. Focal nodular hyperplasia is noted occasionally in the liver adjacent to PCFS. The possibility that PCFS represents an intermediate stage between focal nodular hyperplasia and the more malignant variants of hepatocellular carcinoma is discussed.