An update on primary hepatic solitary fibrous tumor: An examination of the clinical and pathological features of four case studies and a literature review.

BACKGROUND: Primary hepatic solitary fibrous tumor is a rare neoplasm that originates in the submesothelial tissue of the liver and is frequently misdiagnosed because of its rarity and unfamiliar characteristics.

AIM: To analyze, summarize and update the clinical and pathological features of primary hepatic solitary fibrous tumor.

METHODS: We systematically extract the clinical data of 4 cases from the relevant medical records, analyze the macroscopic, histological and immunohistochemical features and review the 59 previously reported cases in the English literatures.

RESULTS: The patients' mean age 50.75 years (range, 49-52 years), and the gender ratio was 1:1. The tumors ranged in size from 2.3 to 12.0cm (average diameter, 7.85cm). The tumors were composed of spindle cells with oval, fusiform or banded nuclei that were arranged in bundled, storiform or peculiar random patterns. Mitosis and hemangiopericytoma-like vessels were occasionally observed. Immunohistochemically, three cases were positive for Signal transduction and activator of transcription 6, cluster of differentiation 34, B-cell lymphoma-2 and vimentin but were negative for nervous, muscular and hepatocellular markers. Hepatic lobectomy was performed in all cases, and one patient received adjuvant chemotherapy simultaneously. One patient suffered two recurrences without metastasis, and the remaining patients experienced favorable outcomes.

CONCLUSIONS: A consensus on the essential and definite diagnostic criteria for primary hepatic solitary fibrous tumor must be reached in a timely manner. Signal transduction and activator of transcription 6 is a highly sensitive and specific immunohistochemical marker for primary hepatic solitary fibrous tumor.