Possible neuroleukemiosis in two patients with acute myeloid leukemia in complete bone marrow remission

Hematologic malignancies and hematopoietic stem cell transplantation

Paraneoplastic neurologic syndromes are rarely associated with hematologic malignancies. In their rarity, lymphomas are the diseases with more frequent paraneoplastic neurologic syndrome. High-risk antibodies are absent in most lymphoma-associated paraneoplastic neurologic syndromes, with the exception of antibodies to Tr/DNER in paraneoplastic cerebellar degeneration, mGluR5 in limbic encephalitis, and mGluR1 in some cerebellar ataxias. Peripheral nervous system paraneoplastic neurologic syndromes are rare and heterogeneous, with a prevalence of demyelinating polyradiculoneuropathy in non-Hodgkin lymphoma. Polyneuropathy, organomegaly, endocrinopathy, monoclonal gammopathy, skin changes (POEMS) is a rare, paraneoplastic syndrome due to an underlying plasma cell disorder. The diagnosis is based on defined criteria, and vascular endothelial growth factor (VEGF), not an antibody, is considered a reliable diagnostic marker that also mirrors therapy response. As with the paraneoplastic neurologic syndromes in solid tumors, therapies rely on cancer treatment associated with immunomodulatory treatment with better response in PNS with antibodies to surface antigens. The best outcome is generally present in Ophelia syndrome/limbic encephalitis with anti-mGluR5 antibodies, with frequent complete recovery. Besides patients with isolated osteosclerotic lesions (where radiotherapy is indicated), hematopoietic stem-cell transplantation is the therapy of choice in patients with POEMS syndrome. In the paraneoplastic neurologic syndromes secondary to immune checkpoint inhibitors, discontinuation of the drug together with immunomodulatory treatment is recommended.

Peripheral Nervous System Involvement in Lymphoproliferative Disorders

Peripheral neuropathies are a vast group of diseases with heterogeneous aetiologies, including genetic and acquired causes. Several haematological disorders may cause an impairment of the peripheral nervous system, with diverse mechanisms and variable clinical, electrophysiological and pathological manifestations. In this practical review, we considered the main phenotypes of peripheral nervous system diseases associated with lymphoproliferative disorders.

The area of intersection of neurological and haematological fields is of particular complexity and raises specific problems in the clinical practice of lymphoproliferative disorders. The personal crosstalk between neurologists and haematologists remains a fundamental tool for a proper diagnostic process which may lead to successful treatments in most cases.