Inflammatory fibrosarcoma: a clinicopathologic study of 6 cases

Inflammatory fibrosarcoma is very uncommon low grade myofibroblastic tumor. We report the pathologic features of inflammatory fibrosarcoma and outcomes of the 6 patients. The age ranged from 12 to 64 years; 3 patients were younger than 25 year. The diagnosis of inflammatory fibrosarcoma was made by autopsy in 4 patients. 2 patients had local recurrences and 4 patients had distant metastases. Follow-up showed the death of 4 patients during 7-14 month after diagnosis. The tumors were 7-12 cm; sites included the mediastinum (4 patients), pelvis and liver. All tumors showed predominantly the hypercellularity and atypical cytologic features of inflammatory myofibroblastic tumor, however, areas of nuclear enlargement and necrosis were identified. Immunohistochemically, cytoplasmic ALK1 reactivity was seen only in 1 patient. The ALK rearrangement was confirmed by FISH in same case.

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