PT - JOURNAL ARTICLE AU - Lidiia Prakhova AU - Valeriy Lebedev AU - Aleksandr Ilves AU - Yulia Nazinkina TI - Monoclonal gammopathy of undetermined significance (MGUS) manifestation in CNS: a regular or chance occurrence? AID - 10.1136/bcr-2020-237726 DP - 2021 Mar 01 TA - BMJ Case Reports PG - e237726 VI - 14 IP - 3 4099 - http://casereports.bmj.com/content/14/3/e237726.short 4100 - http://casereports.bmj.com/content/14/3/e237726.full SO - BMJ Case Reports2021 Mar 01; 14 AB - Monoclonal gammopathy of undetermined significance (MGUS)-associated involvement of the peripheral nervous system is widely reported in the literature. At the same time, involvement of central nervous system (CNS) occurs far less frequently. Analysing the reported cases, almost all the authors pose the question whether there is a relationship between CNS involvement and MGUS, and at what stage it is necessary to begin therapy of haematological disorders. The limited number of reported cases precludes us from getting a definite answer to these questions, thus making further accumulation of clinical data highly relevant. In this article, we present two cases of CNS involvement in patients with MGUS, which, in our opinion, may suggest the existence of a causal relationship between MGUS and CNS involvement. Currently, the above hypothesis cannot be taken as proved due to the lack of a sufficient number of clinical observations and scientific studies. Therefore, the issue of MGUS-associated CNS involvement requires further research.