Angioimmunoblastic T-cell lymphoma with intramedullary production of platelet-derived growth factor and possibly complicating myelofibrosis: report of a case with review of the literature.

A 65-year-old man was diagnosed with angioimmunoblastic T-cell lymphoma (AITL) with bone marrow (BM) infiltration and myelofibrosis (MF). The BM infiltration and the condition of the MF improved following CHOP therapy (cyclophosphamide hydrate, doxorubicin hydrochloride, vincristine sulfate, and prednisolone). After complete remission was achieved, early central nervous system recurrence was noted, with no evidence of BM infiltration or MF. The lymph nodes and BM were examined for cytokines by immunohistochemical staining with monoclonal murine antibodies. The lymphoma cells were positive only for platelet-derived growth factor (PDGF) and negative for basic fibroblast growth factor, fibronectin, vascular endothelial growth factor, transforming growth factor-β (TGF-β), tumor necrosis factor α, interleukin-1β, and interleukin-6. It was thus inferred that the lymphoma cells producing PDGF caused the MF, and that the absence of MF at relapse may have been attributable to the absence of BM infiltration. There have been seven reported cases of AITL with intercurrent MF, although cytokine data (elevations of blood PDGF and TGFβ levels) are available for only one case. The present report is to our knowledge the only report of a case of AITL complicated by MF for which the results of immunohistostaining with anticytokine antibodies are available.