[Small round cell tumours with unknown origin in pathology specimens of iman reza hospital from 1362-1382]

ABSTRACT

The term" small round cell tumour"describes a group of highly aggressive tumours composed of relatively small and monotonous undifferentiated cells with high nuclear to cytoplasmic ratio. This group includes Ewing sarcoma [EWS], Peripheral neuroepithelioma [PN], Primitive neuroectodermal tumour [PNET], Neuroblastoma, Rhabdomyosarcoma [RMS], Desmoplastic small round cell tumour [DSRCT], Lymphoma, Leukemia, Small cell osteosarcoma Small cell carcinoma, Olfactory neuroblastoma, Merkel cell carcinoma, Small cell melanoma, and Mesenchymal chondrosarcoma. Their clinical presentation often overlap, thus making a definitive diagnosis problematic in some cases. Yet, a clear undrestanding of their clinicopathologic features usually allows for a confident diagnosis, especially if immunohistochemistry is used. This is an immunohistochemistry study of small round cell tumours with unknown origin that were diagnosed in pathology service of Imam Reza Hospital from 1362-1382. In this period, we found 24 cases which were reported SRCT without definitive diagnosis the immunohistochemistry kits are from DAKO Company and applied as directed by manufacturers. The SRCT is most frequent in the first decade of life [45%], 13 cases were male and 11 cases were female. IHC influence on diagnosis in 11 cases [46%] confirm the first ordered diagnosis and diagnosis made in another 9 [33%] of SRCTs,and in 2cases[8%]the first diagnosis was changed. Overally in review, 35 cases from 48 SRCTs with unknown origin [%75] were diagnosed by routine stainings by light microscopy without immunohistochemistry