called congenital-infantile fibrosarcoma: does it exist and what is it?
Congenital-infantile fibrosarcoma (CIFS) is a cellular, mitotically active neoplasm with a paradoxically limited biologic potential in most cases. Its phenotype and proliferative features have been incompletely explored with inconclusive results. We studied the clinical, pathologic, immunohistochemical, and flow cytometric features of 26 cases (16 males, 10 females; 92% of cases detected within the first year life; 11 on extremities, 10 on the trunk, 5 in the head and neck). All displayed interlacing fascicles of spindle cells with focal necrosis, mitoses, and a focal hemangiopericytomatous vascular pattern. Immunohistochemically, 22 of 22 cases were reactive for vimentin. Other markers were present in a minority of cases. Flow cytometry of formalin-fixed, paraffin-embedded tissue in 10 cases demonstrated moderate to high proliferation activity and diploid DNA content in nine cases. Follow-up of all 26 patients revealed 20 patients alive and well, 15 without evidence of recurrence, and