Fig. 2
From: KRAS mutation in secondary malignant histiocytosis arising from low grade follicular lymphoma
Diffuse large B-cell lymphoma. A transbronchial biopsy of the lung mass shows a diffuse proliferation of CD20+ large cells with large nuclei, open chromatic, occasional nucleoli associated with frequent apoptotic bodies (a H&E, 600X; b CD20 IHC, 600X). A bone marrow core biopsy shows an abnormal paratrabecular lymphoid infiltrate comprising of small lymphocytes with elongated nuclei (c H&E, 200X; d H&E, 600X). Flow cytometric analysis of the bone marrow aspirate (not shown) identified a monotypic, surface lambda light chain-restricted B-cell population that was dim CD10+ and CD5-, consistent with bone marrow involvement by follicular lymphoma