Abstract: Objective To explore the early diagnostic value of the bone marrow examination for detecting distant metastasis of children with retinoblastoma (RB), and to provide the basis for the occasion of performing bone marrow examination in RB patients. Methods The complete medical records of 91 RB patients who diagnosed clinically or pathologically at Beijing Children's Hospital (BCH) Affiliated to Capital Medical University seen from Nov. 2009 to May 2014 were retrospectively analyzed. Results Totally 91 cases underwent bone marrow examination, bone marrow biopsy was performed for 70 cases at the same time. There were 48 male (52.7%) and 43 female (47.3%), with a mean age of 25.1 months (bilateral 16.3 months, unilateral 29.0 months). Among 91 patients who had undergone bone marrow aspiration, in 16 cases the puncture was done at single site while in 75 at two sites (sternum and posterior iliac crest). Juvenile lymphocytes of bone marrow smear were more than 5% in only eight cases. Just one extra-ocular stage patient was confirmed to have bone marrow metastasis by bone marrow biopsy, the rest seven patients were negative. These eight patients were followed up till April 25th, 2016, the follow-up time was between 29 months to 54 months, six cases had stable disease, one died, one case was lost to follow up. Conclusion The rate of early bone marrow involvement in group D and group E of intraocular RB is extremely low, so bone marrow examination could not be done routinely. But when clinical stage is ambiguous, or who is an extra-ocular stage patient or there are imaging risk factors of intraocular RB, bone marrow examination and/or bone marrow biopsy should be done to make definite diagnosis. In addition, RB patients were young, bone marrow is in an active hyperplasia, the result of bone marrow examination will be affected by some factors, so bone marrow biopsy will be needed to clarify the nature of the juvenile cells.

Key words: retinoblastoma, bone marrow inspection, early diagnosis