Granulocytic sarcoma with expression of CD30.

A case of a young man with a spinal epidural tumour, initially diagnosed as large cell anaplastic malignant lymphoma, is reported. The tumour consisted of poorly differentiated cells showing immunoreactivity with antibodies directed against CD30 and CD45. Ten months later the patient developed acute myeloid leukaemia. The histological slides of the epidural tumour were reviewed, including additional enzymochemical and immunochemical stains. As the tumour showed immunoreactivity for myeloperoxidase and chloroacetate esterase, it was reclassified as a granulocytic sarcoma.