Lumbar Puncture Artifacts: Bone Marrow Components, Cartilage Cells, etc

If the patient’s spine is anatomically abnormal or is injured, or if the patient’s posture during the lumbar puncture is insufficiently relaxed, there is a greater likelihood that the lumbar puncture needle will strike against bone and that bone marrow components will be aspirated together with the CSF. Other cell types and tissues that may appear in the CSF as an artifact of lumbar puncture are cartilage cells, skin cells, capillaries and subdermal connective tissue cells. Capillaries of the plexus choroideus or of ventricle walls are occasionally seen in ventricular CSF. Among the unintentionally aspirated bone marrow cells, the CSF cytologist may find the many different immature forms associated with erythropoiesis (ranging from proerythroblasts to normoblasts), myelopoiesis (from myeloblasts to metamyelocytes), monocytopoiesis (from monoblasts to promonocytes), and thrombocytopoiesis (from megakaryoblasts to megakaryocytes). If these cell types are not recognized, they can easily be misdiagnosed, e.g., as neoplastic or tumor-suspect cells (cf. the tumor cell criteria in Chapter 5). Examples of these immature forms are shown in Figures 2.10–2.15. Immature progenitor stages in the lymphocytic series are shown in Figure 2.16 and in some of the illustrations in other parts of this book dealing with infectious and inflammatory processes (see Chapter 3) and leukemic meningitis (Chapter 5, Leukemia). Typical cartilage cells are shown in Figure 2.17, and capillaries in ventricular CSF are shown in Figure 2.18. 18 2 Cell Populations in the Normal Cerebrospinal Fluid Thieme-Verlag Frau Langner Sommer-Druck Feuchtwangen Kluge et al. Atlas of CSF WN 024612/01/01 TN 143161 3.11.2006 Chapter-2