EVIDENCE FOR MOLECULAR HETEROGENEITY IN HUMAN GANGLIONEUROBLASTOMA

Ganglioneuroblastomas are tumors of sympathetic cell origin that conta in both primitive neuroblastomalous and mature ganglioneuromatous elem ents. It is thought that these tumors arise from a single cellular clo ne and that the morphologically distinct components of ganglioneurobla stomas represent cells in different stages of differentiation. Two pat hologic variants of this tumor, composite and diffuse, have been descr ibed; metastasis is more commonly seen with composite ganglioneuroblas tomas. We analyzed a composite ganglioneuroblastoma for N-myc copy num ber at initial resection and 2 years later after progressive disease. In the second sample the more differentiated portion of the tumor was analyzed separately from the neuroblastic foci for N-myc copy number a nd DNA ploidy. The DNA content and N-myc copy number differed in the t wo morphologically discrete areas of the tumor, suggesting that at lea st two clones were present. More composite ganglioneuroblastomas need to examined to determine whether these tumors are largely composed of tumor cell populations with molecular heterogeneity.