Non lymphomatous clonal B-Cell populations in enlarged lymph nodes in acquired immunodeficiency syndrome.

Clonal B-cell populations in non-lymphomatous processes have been sporadically reported in enlarged reactive lymph nodes and mucosa-associated lymphoid cell populations. These generally small clones are considered non-malignant proliferations of B-lymphocytes determined by an abnormal response to bacterial or viral antigen stimulation. In cases reported in literature, clonality was detected by light chain assessment and or by polymerase chain reaction (PCR) analysis of immunoglobulin heavy chain (IgH) gene in histologically and clinically proven non lymphomatous processes. In this study the clinical, cytological, phenotypical and pathological features of three HIV patients in which non-lymphomatous clonal B-cell populations detected in enlarged lymph nodes are reported. All the patients complained for later cervical lymph nodes enlargement, positive at the FDG-positron emission tomography scan. Fine needle cytology, coupled with flow cytometry showed atypical lymphoid cell proliferations and kappa (2 cases) or lambda (1 case) light chain restriction. Reactive, non lymphomatous nature of these processes were then proven by histological control in two cases and by clinical follow-up in the last one; corresponding clinical and pathological aspects are discussed. Clonal B-cell populations in non-lymphomatous processes can sporadically occur in enlarged reactive lymph nodes in immunodeficiency as well as in autoimmune processes. Awareness of the phenomenon and attention should be paid in the evaluation of corresponding pathological features and in the clinical management of corresponding patients.