The use of bone marrow aspirations and lumbar punctures at the time of diagnosis of retinoblastoma.

Lumbar punctures (n = 115) and bone marrow aspirations (n = 114) were performed as part of the routine initial diagnostic evaluation of 115 children with retinoblastoma. Three spinal fluid examinations were positive for tumor cells, and bone marrow smears of three children demonstrated clumps of tumor cells. Five of the six positive studies were in patients with stage IV (extraglobar) disease. These results show that demonstrable CSF or bone marrow involvement is so infrequent an event at diagnosis in patients without symptoms, signs, or histologic evidence of tumor dissemination (stages I-II) as to support a recommendation that these studies need not be performed routinely in such patients. If, after enucleation, there is evidence of extraglobar extension, or if patients have symptoms or signs of CNS or systemic spread (stages III or IV), both procedures should be performed to accurately stage disease and provide baseline measurements of tumor involvement for monitoring of response to chemotherapy and/or irradiation. These results have importance in terms of justification of invasive work-up of most (greater than 85%) affected children, and cost containment.