IN-VITRO NEUROBLASTOMAL CLUMP FORMATIONS AS AN INDICATOR OF A BONE-MARROW METASTASIS

In a long-term culture of bone marrow taken from a child with a suspec ted abdominal tumor, a large number of globular in vitro clumps develo ped within 5 days, although the bone marrow used had tested negative t o the presence of abnormal cells. Light microscopic and marker studies of these clumps provided evidence of neuroblastomal origin, and the d iagnosis of a neuroblastoma was confirmed by a subsequent cathecholami ne assessment and the histological findings of the excised tumor. Of t hree in vitro culture methods tested, i.e., a long-term bone marrow cu lture (LTBMC), a liquid culture, and a methylcellulose clonal cell cul ture, the LTBMC was found to be the most sensitive for detecting tumor cells. This LTBMC was considered to be useful for not only achieving a definitive neuroblastoma diagnosis but also the early detection of b one marrow metastasis in N-myc gene amplified neuroblastomas.