Necrotizing eosinophilic granulomatous lymphadenitis with ring- and C-shaped granulomas—an underrecognized specific manifestation of nodal Churg-Strauss syndrome

Nodal involvement as the main or prominent clinical manifestation of Churg-Strauss Syndrome (CSS) is uncommon but is being recognized with increasing frequency. Lymph node biopsies are only obtained in CSS cases in which the classic clinical and serologic manifestations of the disease are not clear, and thus the nodal biopsy becomes crucial for recognizing a disorder associated with severe morbidity and mortality. Unfortunately, lymph node pathologists are rarely confronted with this disease, and detailed descriptions of pathologic findings in nodal CSS are scant, with only one previous detailed report. We confirmed the specificity of the findings described in the previous report, and expanded the morphologic and immunophenotypic features of nodal CSS, including a possible pathogenetic role of IgG4. The diagnosis allowed successful treatment of symptoms that had plagued the patient for over 2 years and allowed the rapid recognition of a potentially fatal acute alveolar hemorrhage that occurred after the patient underwent an aortic valve replacement for bacterial endocarditis. Treatment with anti-interleukin-5 humanized monoclonal antibody mepolizumab allowed decreasing the risk of infection and poor healing associated with high-dose steroids and cyclophosphamide.