Nodular lymphocyte-predominant Hodgkin lymphoma cytopathologic correlates on fine-needle aspiration

BACKGROUND: Nodular lymphocyte-predominant Hodgkin lymphoma (NLPHL), a rare subtype of Hodgkin lymphoma, is an indolent tumor with frequent instances of disease recurrence but a favorable prognosis. To the best of the authors' knowledge, there are only limited descriptions of NLPHL in the cytology literature because it was only formally recognized as a distinct entity in 1994. METHODS: In the current study, all cases of NLPHL diagnosed on excisional biopsy (n = 6 cases) at the study institution between 2000 and 2011 that had undergone previous fine-needle aspiration (FNA) were reviewed, with a focus on cytomorphologic features. RESULTS: Four of 6 cases were termed benign on FNA; however, there was retrospective recognition of characteristic LP cells in all cases. Unlike classical Hodgkin lymphoma, the tumor cells of NLPHL were often found to be mononucleate and presented in a background of small lymphocytes. Other features identified included epithelioid histiocytes and numerous bare atypical nuclei. CONCLUSIONS: Cases of NLPHL are commonly misdiagnosed as benign reactive lymphoid tissue and therefore a careful search using high magnification for LP cells is recommended in the evaluation of lymph node FNAs.