Thymoma associated with myasthenia and autonomic anti-Hu paraneoplastic neuropathy.

Along with myasthenia, other paraneoplastic neurological syndromes (PNS) may occur in thymoma. Anti-Hu antibodies and a clinical "anti-Hu syndrome" characterized by encephalitis and/or painful neuropathies have been reported in only three patients at the time of the diagnosis of thymoma. We describe a severe anti-Hu-related autonomic neuropathy with gastrointestinal paresis and intestinal pseudo-obstruction with malabsorption that occurred concomitantly with the worsening of myasthenic symptoms long after the initial diagnosis of thymoma in a young patient. The clinical anti-Hu syndrome preceded the radiological diagnosis of thymoma recurrence. Treatment with plasma exchange led to a transient improvement of neurological symptoms.