Fine needle aspiration cytology in the diagnosis of Hodgkin lymphoma: Hits and misses

Background: Fine needle aspiration (FNA) is said to have greater diagnostic accuracy in Hodgkin lymphoma (HL) as compared to non-Hodgkin lymphoma (NHL). In spite of this, HL accounts for most of the false negative cytodiagnoses among lymphomas. Aims: To evaluate the accuracy of FNA in HL and to identify the diagnostic pitfalls. Materials and Methods: A retrospective study of 18 biopsy-proven cases of HL that had a preceding FNA from the same lymph node. Results: Nine out of eighteen cases were labeled HL, which were diagnosed on the basis of atypical mononuclear cells in preference to classic Reed-Sternberg (RS) cells. Three cases were termed lymphoproliferative, which showed the presence of only atypical mononuclear cells with eosinophilic nucleoli. Six cases were false negative cases. Four of these were hypocellular with biopsy in two cases displaying marked fibrosis. The remaining two cases were labeled reactive and review also showed no additional findings. Conclusions: Presence of atypical mononuclear cells in cytology should prompt a cautious search as classic RS cells may not be a prominent feature in aspirates of HL. Focal involvement and abundance of reactive lymphoid cells may lead to false negative diagnoses. Hypocellularity of aspirates disproportionate to lymph node size warrant caution. Overall, FNA is useful in the diagnosis of HL, provided one is aware of the pitfalls. It is particularly valuable in screening cases that will require biopsy.