IMMUNOCYTOLOGIC STAINING OF CYTOKERATIN IN BONE-MARROW ASPIRATES TO DETECT MICROMETASTATIC CELLS FAILS IN PATIENTS WITH METASTATIC UROLOGICCARCINOMA

The detection of cytokeratin-positive cells in bone marrow of patients with various carcinomas is considered an adverse marker. To establish a routine diagnostic procedure to detect these cells in patients with urologic carcinoma, we evaluated different immunocytological techniqu es in parallel. The study included 50 patients with urologic carcinoma (16 with metastatic disease) and 10 healthy volunteers. Bone marrow w as aspirated from the iliac crest; after density centrifugation, cytoc entrifuged specimens were stained according to optimized modifications of conventional immunocytologic techniques. Overall only 3% of patien ts with locally restricted carcinoma and only 19% with metastatic dise ase showed cytokeratin-positive bone marrow cells. Nonspecific labelin g of bone marrow cells in the immunoglobulin isotype controls was a ma jor problem, demonstrating the need for numerous detailed controls. If all nonspecific reactions were excluded, up to 20% of the healthy con trols yielded positive results as well. The presence of cytokeratin-po sitive cells in bone marrow aspirates shows only slight correlation wi th systemic metastasis. The biologic and clinical relevance of this im munocytologic marker must be judged cautiously.