THE NEED FOR SPECIALIST REVIEW OF PATHOLOGY IN PEDIATRIC CANCER

A retrospective histopathological review of 2104 cases of solid tumour was carried out to assess the variability in diagnosis of childhood c ancer. Cases were subject to three independent, concurrent opinions fr om a national panel of specialist pathologists. The conformity between them was analysed using the percentage of agreement and the kappa sta tistic (rc), a measure of the level of agreement beyond that which cou ld occur by chance alone, and weighted kappa (kappa), which demonstrat es the degree of variation between opinions. The major groupings of th e Birch-Marsden classification were used within which tumours were ass igned for kappa analysis according to the clinical significance of the differential diagnoses. The mean agreement for all tumours together w as 90%; kappa = 0.82, w kappa = 0.82. Retinoblastoma achieved the high est kappa value (1.0) and lymphoma the lowest (0.66). Of the cases, 16 .5% had their original diagnoses amended and the panel confined the or iginal diagnosis of paediatric pathologists in 89% of cases compared w ith 78% for general pathologists. The varying levels of agreement betw een experts confirm the difficulty of diagnosis in some tumour types, suggesting justification for specialist review in most diagnoses. Spec ialist training in paediatric pathology is also recommended.