Malignant fibrous histiocytoma of the pancreas - A case report with genetic analysis

BACKGROUND. Malignant fibrous histiocytoma (MFH) is the most common type of soft tissue sarcoma in adults; it occurs frequently in the extremities, the trunk, or retroperitoneal tissues. MFH rarely is detected in digestive organs, such as the liver or stomach. METHODS. The authors report a patient with MFH of the pancreas who was treated with surgery alone. The tumor was studied for genetic alterations in the p53, p16(ink4a), and DPC4 tumor suppressor genes as well as the K-ras oncogene by immunohistochemistry, single strand conformation variant (SSCV) analysis, and direct DNA sequencing. RESULTS. The authors believe that this is the 13th report of primary pancreatic MFH in the world literature and the first genetic analysis of this rare tumor. The patient is alive with no evidence of recurrence 34 months after surgery. Immunohistochemistry revealed no abnormal accumulation of the p53 protein and normal nuclear p16 expression. Mutation analysis of the p53, p16, DPC4, and K-ras genes showed only a polymorphism at codon 72 of the p53 gene and no mutations in any of the genes. CONCLUSIONS. Genotypically, MFH of the pancreas is clearly different from other malignant pancreatic tumors, which further supports the hypothesis that this tumor is a rare but distinct entity. Cancer 1999;85:2352-8. (C) 1999 American Cancer Society.