In this report authors describe malignant neoplasms diagnosed in newborns <28 days, who were treated in the Department of Pediatric Oncology and Haematology Section of the 2nd Department of Pediatrics, Faculty Hospital Motol between 1990 - 2000. During this period twenty one neonates (9 boys and 12 girls) with neoplasms were diagnosed. The histologic diagnoses were neuroblastoma (n = 11), germ cell tumor/teratoma (n = 5), retinoblastoma (n = 2), congenital fibrosarcoma (n = 1), alveolar rhabdomyosarcoma (n = 1), acute lymphoblastic leukaemia (n = 1). Diagnosis was established between 1 - 8 days after delivery (median 2 days). Therapy: eleven patients were treated with surgery alone - neuroblastoma (n = 7), sacrococcygeal teratoma (n = 3), congenital fibrosarcoma (n = 1), six patients with surgery and chemotherapy - neuroblastoma (n = 4), germ cell tumor (n = 2)). Two patients with retinoblastoma were treated with chemotherapy and concomitant local laser therapy.Radiotherapy treatment was necessary in two patients - disease progression (retinoblastoma) and relapse (neuroblastoma). One patient with a relapse of germ cell tumor underwent megachemotherapy with reinfusion of autologous progenitor stem cells. Fifteen children (71 %) are long-term survivors, two patients succumbed to the disease progression and one patient to the toxic complications related to the treatment. Three patients (15 %) are lost to follow up. Follow up of survivors ranges from 1 day - 134months (median 67 m.). No associated anomalies were noticed. Familiar genetic predisposition was established in two patients with retinoblastoma.

        Key words: neonatal neoplasms, diagnosis, treatment, outcome