Cytodiagnosis of extramedullary hematopoiesis in thyroid gland unravelling an asymptomatic hematological malignancy.

Extramedullary hematopoeisis (EMH), also known as myeloid metaplasia can be seen in association with various hematological disorders. The common sites of EMH are liver, spleen and lymph nodes; but it can occur in almost any organ and in numerous locations. Involvement of the thyroid gland with EMH has rarely been reported. We present a case of EMH in the thyroid gland in an adult female diagnosed on fine-needle aspiration cytology (FNAC) which further helped in revealing an underlying myeloproliferative neoplasm; chronic myeloid leukemia (CML).