Plasma cell leukemia occurring six months after covid-19 is associated with a paraneoplastic limbic encephalitis

Abstract

A 73-year-old obese individual was diagnosed with an acute COVID-19 infection. The patient’s condition improved, but six months later a new deterioration ensued. Following the appearance of pancytopenia, plasmacytosis involved the peripheral blood (35%), as well as the bone marrow (31%), disclosing an osteoclastic pattern. An encephalitis which prevailed at that stage was of the limbic type. It displayed anti-GABA B-antibodies. Therefore, the condition being neither an infection, nor a metabolic disorder, nor a vascular lesion, is most consistent with an autoimmune reaction. The clinical features were consistent with a plasma cell myeloma, associated with a paraneoplastic syndrome. The diagnosis favored the POEMS syndrome, even though a few criteria were missing. It was sustained by a fluid collection surrounding an enlarged spleen, as well as filling up both pleural gutters. This POEMS case was related with COVID-19, both via the original acute episode, as well as with a late possible subacute COVID-19 pulmonary disorder, assessed by extensive radiologic ground glass changes. In this instance, the patient developed hypoxemic respiratory insufficiency and he died of respiratory failure, in addition to due to the plasma cell leukemia. Thus, we have reported the simultaneous occurrence of a POEMS syndrome, induced by a plasma cell leukemia, and confounded by a pulmonary COVID-19, perhaps with long COVID features.