Granulocytic sarcoma presenting as an orbital mass: report of two cases.

Granulocytic sarcoma is a rare variant of a myeloid malignancy, which shows an extra-medullary tumour mass which is composed of myeloblasts and myeloid precursors with varying degrees of differentiation. It occurs most commonly in bone, periosteum, soft tissue, lymph nodes, and skin; although it can occur anywhere throughout the body. Here, we are reporting two cases of orbital granulocytic sarcoma in children, which presented clinically with proptosis and periorbital swellings, which were first diagnosed by Fine Needle Aspiration Cytology (FNAC). Later, peripheral blood and bone marrow aspirate examinations revealed the evidence of Acute Myeloid Leukaemia (AML). These cases are being documented to demonstrate the utility and diagnostic accuracy of FNAC in evaluation of this entity, in cases of unsuspected AML. Recognition of this rare entity is important, because giving an early aggressive chemotherapy can cause regression of the tumour and thus improve the patient survival.