Incidence of 'dry tap' on bone marrow aspirations in lymphomas and carcinomas. Diagnostic value of the small material in the needle.

Of 2907 bone marrow aspirations in patients with various malignancies, 192 or 6.6% exhibited 'dry tap'. In about 80% of the 'dry tap' there was material present inside the bone marrow needle which gave smears useful for evaluation of the bone marrow cytology. About 23% displayed normal cytology. Bone marrow involvement could be diagnosed in 13 out of 55 'dry tap' in Hodgkin's disease, 41 out of 46 in chronic lymphocytic leukaemia and lymphosarcoma, 6 out of 20 in reticulum cell sarcoma, 6 out of 9 in myelomatosis and 20 out of 45 in carcinoma. In a material of 174 aspirations with tumour cells in the bone marrow aspirate, the highest incidence of 'dry tap' was found in patients with Hodgkin's disease and patients with carcinoma, the lowest incidence in patients with multiple myeloma.