Anti-Ma-associated paraneoplastic cerebellar degeneration in a patient with nodular lymphocyte-predominant Hodgkin lymphoma: a case report

BACKGROUND: Paraneoplastic cerebellar degeneration (PCD) is a devastating paraneoplastic syndrome that occasionally occurs in patients with Hodgkin lymphoma (HL). Anti-Ma2 is a well-characterized onconeuronal antibody and one of the causes of PCD. There has been only one previous report of anti-Ma2-associated paraneoplastic syndrome as a complication of HL. Here we present a rare case of anti-Ma2-associated PCD in a patient with nodular lymphocyte-predominant HL (NLPHL). CASE PRESENTATION: A 77-year-old man with a 3-month history of gait instability and a 2-month history of oscillopsia was referred to our hospital for further investigation. On examination, his cognition was normal. He had nystagmus in all directions of gaze; specifically, he had horizontal and rotatory nystagmus in the primary position, downbeat nystagmus after right, left, and up gaze, and upbeat nystagmus after down gaze. Although his limb ataxia was mild, his trunk ataxia was so pronounced that he was unable to walk without support. We strongly suspected paraneoplastic syndrome and tested for neuronal autoantibodies. The anti-Ma2 antibody was strongly positive in the blood and cerebrospinal fluid but other antineuronal autoantibodies were negative. Computed tomography showed an enlarged lymph node in the right axilla but no masses. Biopsy confirmed a diagnosis of NLPHL. The NLPHL cells stained with anti-Ma-2 antibody in the cytoplasm, suggesting these abnormal cells contained protein that was cross-reactive with Ma-2. CONCLUSIONS: To the best of our knowledge, this is the first case of anti-Ma2-associated PCD in a patient with NLPHL that was confirmed using immunostaining of the lymph node tissue with anti-Ma2 antibody. Our case confirms an association between anti-Ma2-associated PCD and NLPHL.