Molecular evidence of bone marrow involvement in advanced case ot Tgammadelta lymphoma with secondary myelofibrosis

We describe the case of a middle-aged man with long indolent course of generalized Tgammadelta lymphoma. The onset of secondary myelofibrosis made cytological monitoring of the bone marrow infiltrates impossible. As during progression of the disease splenectomy revealed typical histological features of a high-grade hepatosplenic Tgammadelta lymphoma, the low-grade bone infiltrate was considered a secondary lymphoma. The use of the polymerase chain reaction helped to detect a constant and identical monoclonal rearrangement pattern of the T-cell receptor gamma-chain gene in both bone marrow and splenic T-cell infiltrates. The notion of a secondary spread of malignant T-cells to the bone marrow was thereby confirmed despite striking cytological differences between bone marrow and splenic infiltrates. This is the first report of a diagnostic DNA-based molecular approach using fixed decalcified bone marrow. This method may provide a major tool when dealing with myelofibrosis, which normally hampers sampling of cytological specimens.