A monoclonal proliferation of germinal center cells within a lymph node follicle was incidentally discovered during the staging surgical procedures in a patient with Clark III-level cutaneous melanoma. In one of the 19 axillary lymph nodes examined, we identified a single morphologically atypical lymphoid follicle, predominantly composed of medium-sized cells and immunoreactive for B-cell antigens and for the markers of germinal center origin CD10 and bcl-6. A monoclonal rearrangement of the immunoglobulins heavy chains (IgH) was documented by polymerase chain reaction after laser capture microdissection. The cells of the aberrant follicle expressed the bcl-2 protein at higher levels than the surrounding T lymphocytes in the absence of bcl-2 gene rearrangement. We propose for this lesion the designation of incipient follicular lymphoma. The present findings also confirm the previously reported association between melanoma and lymphoproliferative disorders.
Copyright 2001 by W.B. Saunders Company