**4.3. MR spectroscopy**

Characteristic spectroscopic findings for PCNSL include elevated signals of lipid, choline, and lactate and reduced NAA signal **(Figure 5**). Large lipid peaks on lesions without central necrosis are also strongly suggestive of PCNSL [17]. High lipid peak may be due to in‐ creased turnover of the membrane components in transformed lymphoid cells.
