[Histological and immunohistochemical diagnosis of bone marrow metastases of neuroblastomas].

A retrospective, morphological and immunochemical study was performed on 60 bone marrow biopsies (BOM) and 12 tumor specimens surgically excised, from 9 patients with neuroblastoma (NB). Immunochemistry concerned "neuron-specific enolase" (NSE), chromogranin A (CGA) and synaptophysin (SP). The results of immunochemical stains and the study of reticulin network on the argentic stain were compared to the results of morphological evaluation on the routine stain. NSE, CGA and SP staining of tumor cells (part or all of them) was obtained from all surgical specimens. 17/75 BOM (20%) were discarded because of poor material. NB cells were observed in 24 BOM from 3 patients. Tumor cells formed large strands (1 patient) or nests (2 patients) associated with segregated cells. Diagnosis of metastatic BM involvement was negative or doubtful for 6 BOM (3 obtained at the same time, 2 patients), in which NB cells were clearly demonstrated by immunochemical staining of NSE and/or CGA. Reticulin and/or collagen myelofibrosis was present in 32/35 BOM from the 3 patients metastatic in bone marrow (BM+) even if NB cells could not be demonstrated in these samples.