Hyaline inclusions in a synovial sarcoma following intra-arterial chemotherapy.

Hyaline inclusions were noted in cells of a typical synovial sarcoma following intra-arterial chemotherapy. Ultrastructural study revealed that the inclusions were cytoplasmic aggregates of intermediate filaments. Since the inclusions were not present in the tumor prior to treatment, it is suggested that they may have formed as a result of the infusion and that their presence may be an indicator of chemotherapeutic effect.