Cytologic findings in a case of T-cell rich B-cell lymphoma: potential diagnostic pitfall in FNA of lymph nodes.

Fine-needle aspiration biopsy (FNAB) is a reliable diagnostic technique for most palpable masses. This technique is utilized routinely to diagnose metastatic carcinoma and melanomas in lymph nodes. However, the role of FNAB in the investigation of lymphoproliferative lesions is still controversial. Recent publications have supported the use of FNAB cytology, in conjunction with immunophenotyping, as an accurate, reliable diagnostic modality for the classification of most lymphomas (Sneige et al., Acta Cytol 1990; 34:311-322; Skoog and Tani, Diagn Oncol 1991; 1:12-18; Robins et al., Am J Clin Pathol 1994; 101:569-576; Katz, Clin Lab Med 1991; 11:469-499). We present a case of a T-cell rich, large B-cell lymphoma. Material obtained by FNAB mimicked a reactive process by both cytomorphological and immunophenotypical analysis. This case demonstrates a potential pitfall in the use of FNAB to evaluate lymphoproliferative disorders even when used in conjunction with immunophenotypic studies. The case also emphasizes the need for detailed clinical and prior pathologic information when a cytologic sample is being evaluated for a lymphoproliferative disorder. To our knowledge, the cytomorphologic findings of this particular type of lymphoma have not been previously described as seen on an FNAB.