Article Text
Abstract
Fine needle aspiration cytology (FNAC) is used for preoperative diagnosis of paediatric renal tumours especially in centers where preoperative chemotherapy is advocated in Wilms tumour. This review focuses on salient cytological features in specific paediatric renal tumours, approach to resolving a differential diagnosis and role of ancillary methods in diagnosis of paediatric renal tumours. Crucial differential diagnoses include distinguishing a) Wilms tumour from benign tumours in the kidney like multicystic nephroma or congenital mesoblastic nephroma; b) Aggressive non Wilms tumours of kidney like rhabdoid tumour of kidney and c) Wilms tumour from other paediatric round cell sarcomas like neuroblastoma, Non Hodgkin’s lymphoma etc. An approach based on classifying smears as per their cellular patterns an as triphasic, round cell, spindle cell and an epithelioid cell type assists in classifying paediatric renal tumours on cytology. Immunocytochemistry for WT1, cytokeratin, synaptophysin, leukocyte common antigen and MIC2 will aid in evaluating round cell tumours in the renal region while WT1, bcl2, vimentin and desmin will be useful for spindle cell tumours in that region. Extra material can also be evaluated for demonstration of specific cytogenetic abnormalities in these tumours. A check list of common tumours in a particular age group, relevant clinical information, awareness of distinctive and overlapping cytologic features, appropriate use of immunocytochemistry with cytogenetics go a long way in ensuring an accurate cytologic diagnosis. Used judiciously, FNAC is as effective a tool as a core biopsy for preoperative diagnosis of paediatric renal tumours and with experience a 92% accuracy rate can be achieved.