Paraneoplastic neurological syndromes in Hodgkin and non-Hodgkin lymphomas

Paraneoplastic neurological syndromes (PNSs) rarely associate with Hodgkin lymphoma (HL) and non-HLs (NHLs). Except for paraneoplastic cerebellar degeneration (PCD) in HL and dermato/polymyositis in both HL and NHL, other PNSs are uncommon and have only been reported as isolated case reports or short series. There are several important differences in PNSs when occurring in association with HL and NHL compared with those associated with solid tumors. First, some PNSs such as sensory neuronopathy or Lambert-Eaton myasthenic syndrome rarely occur in lymphomas, whereas others, such as granulomatous angiitis, are only described in HL. Second, onconeural antibodies are absent in most PNSs associated with lymphomas with the exceptions of Tr (delta/notch-like epidermal growth factor-related receptor) in PCD and mGluR5 in limbic encephalitis (LE). The antigens recognized by these antibodies are not expressed in lymphoma cells, suggesting the tumor itself does not trigger the PNS. Third, unlike patients with solid tumors in patients with lymphoma, the PNSs often develops at advanced stages of the disease. Furthermore, the type and frequency of PNSs are different between HL and NHL; whereas LE and PCD occur almost exclusively in patients with HL, sensorimotor neuropathies and dermatomyositis are more frequent in NHL.