Bone marrow involvement at presentation in pediatric non-haematological small round cell tumours

Pediatric small round cell tumors (SRCT) are a group of neoplasms occurring in children, which have in common a cytomorphology of groups of small round cells with scanty cytoplasm. The common SRCT encountered are neuroblastoma, retinoblastoma, Ewing's sarcoma/peripheral neuroectodermal tumor (PNET), rhabdomyosarcoma and lymphoma which show varying degrees of bone marrow involvement and bone marrow evaluation forms a part of the initial staging procedure. This study was undertaken to evaluate marrow involvement at presentation in pediatric non hematological SRCT. 7833 bone marrow aspirates done over a period of three years in different malignancies were analysed and of these 180 aspirates were performed in patients of pediatric non hematological SRCT at presentation. These cases were evaluated in detail for incidence of marrow involvement. Thirty two (17.7%) cases showed marrow involvement and these cases have been analysed with respect to the primary tumor. The SRCT showing involvement of bone marrow included neuroblastoma (48.8%), retinoblastoma (11.1%), Ewing's sarcoma/PNET (8.6%) and rhabdomyosarcoma (3.2%). These findings are discussed in the light of available world literature.