Frequency of Malignant Solid Tumors in Children

Objective: To find out the frequency of malignant solid tumors in children (cTl5 years). Setting: All cases of pediatric malignant solid tumors which were diagnosed in the section of histopathology at the Aga Khan University Hospital, Karachi during the period of two years. Methods: These tumors were initially evaluated on H&E stained sections and special stains were also performed whenever indicated. The undifferentiated tumors were evaluated immunohistochemically by using a panel of antibodies on sections from routinely processed, fornialin fixed, paraffin embedded tissu.e blocks. Results: Of two hundred and fifty three (253) consecutive cases of paediatric malignant solid tumors, lyinphorna (26.1 %) was the most common tumor followed by central nervous system tumors (16,6%), osteosarcoma (7.5%), rhabdomyosarcoma (6.7%), neuroblastoma (5.1%), Wilm\'s tumor (5.1% %), Ewing’s sarcoma (4.7%), retinoblastoma (4.7%), germ cell tumor (4.4%) and primitive neuroectodermal tumor (4%) in order of frequency. In seven cases (2.8%), the nature of lesion remained undetermined even after immunohistochemical staining. Rest of malignant tumors (12.3%) included the rare entities like synovial sarcoma, nasopharyngeal carcinoma, leiomyosarcoma, malignant schwannoma and thyroid carcinoma, etc. Conclusion: Lymphoma was the most frequent Paediatric tumor. The frequency of childhood central nervous to the other series from different regions of Pakistan system tumors was quite high as compared UPMA 50:86,2000).