Fine needle aspiration cytology of Ki-1 positive large cell lymphoma-a case report-.

Ki-1 lymphoma is a sort of high grade large cell lymphoma and defined on the basis of the reactivity of the tumor cells with monoclonal antibody Ki-1. On fine needle aspiration cytology, the reported case is rare and the differential diagnosis is not easy, especially from undifferentiated carcinoma and Hodgkin's lymphoma. We experienced a case of fine needle aspiration cytology of Ki-1 positive large cell lymphoma in a 61-year old male patient. Fine needle aspiration cytology from the cervical lymph node disclosed hypercellular smears with large single cells on polymorphous lymphoid background. The tumor cells had abundant dense cytoplasm and large nuclei with Irregular profiles. Although most cells were mononuclear binucleated and multilobed/multinucleated cells were also seen Immunohistochemistry was done and revealed strong positive staining for Ki-1 antigen.