Fine needle aspiration cytology of primary thyroid lymphoma: a report of ten cases

Primary lymphoma is an uncommon malignancy of the thyroid, comprising of 0.6 to 5 per cent of thyroid cancers in most series. Primary thyroid lymphomas (PTL) occur most commonly in elderly women and are commonly of B- cell origin. These frequently present in clinical stage IE and IIE. We report here ten cases of PTL diagnosed over a period of about 7 years in our institute. Out of these ten cases, nine were diagnosed on fine needle aspiration cytology (FNAC) and one case was misdiagnosed as lymphocytic thyroiditis. This case was diagnosed as Non- Hodgkin's lymphoma on surgical specimen. Five patients are disease free and doing well, while two died of disease and the other two were lost to follow-up. One patient is currently on chemotherapy. The salient clinical, biochemical, radiological features, FNA findings along with diagnostic difficulties are discussed.