Lymph Nodes and Spleen

Lymph node puncture is a simple procedure that has become an indispensable part of hematologic diagnosis. It can be performed anywhere and at any time. Repeated aspirations provide an excellent means of monitoring the progress of certain disorders, and multiple lymph nodes can be aspirated concurrently to increase the accuracy of the evaluation. Lymph node cytology yields almost as much information as the examination of histologic sections in many disorders (e.g., Hodgkin’s disease, tuberculous lymphadenitis, sarcoidosis, solid metastatic tumors). However, much experience in the interpretation of lymph node smears is necessary for an accurate evaluation. Above all, the examiner must be familiar with the great morphologic diversity of reactive lymph node changes, and therefore particular attention is given to these changes in the present chapter. Four main types of cytologic pattern may be seen on the examination of smears prepared from lymph node aspirate (after Theml 1986): 1. A reactive cellular composition without specific cellular elements. Foci or infections are usually causative, and reactive hyperplasia should be suspected. 2. A reactive cellular composition with specific elements, such as a predominance of epitheloid cells (consistent with sarcoidosis) or Langhans’ cells (consistent with tuberculous lymphadenitis). Hodgkin’s cells and Sternberg cells should raise suspicion of Hodgkin’s disease. 3. A monotonie picture composed of lymphatic cellular elements, consistent with non-Hodgkin’s lymphoma. 4. Cells extrinsic to the lymph node, consistent with metastatic tumor.