Severe acute multineuropathy in Churg-Strauss syndrome in a patient with a history of melanoma

We describe the clinicopathologic features of a 69-year-old mail affected with acute onset Churg-Strauss syndrome with major peripheral nerve involvement. At admision the patient presented a one-week history of distal upper-limb asymmetrical paresthesias. Asthma had been present since the age of 55 and treated with leukotriene receptor antagonists (LTAs, Montelukast) fora few years. Multiple pulmonary infiltrates had been diagnosed during follow-up for melanoma. During hospitalization lie showed rapidly progressive weakness worsening within a few hours; cerebrospinal fluid analysis, cervical MRI, head CT scan, nerve conduction Studies and peripheral nerve and skeletal muscle biopsies were performed. Blood analysis showed leukocytosis and marked eosinophilia; p-ANCA were positive. Sural nerve biopsy showed a marked loss of myelinated fibers, thrombosed vessels surrounded by mononuclear and eosinophilic cells, necrotizing and hyaline degeneration. Eosinophilic infiltrates were shown in MayGaunwald-Giemsa stained sections. The eosinophils mostly Occupied the Outer zone of the adventitia at the margin of the active lesion. Perivascular cellular infiltrates within the epineurium were immunoreactive for T-lyrnphocytes and macrophages. Strong HLA-DR immunostaining was present in the perineurium and membrane attack complex deposition was present in a few endoneurial capillaries. Muscle biopsy showed neurogenic changes and one Vessel surrounded by mononuclear cells. After a few days of corticosteroid therapy leukocytosis and eosinophilia normalized and the patient's clinical features stabilized.