Abstract

A 30-year-old male presented to the hematologist with signs suggestive of recurrent infections and no evidence of organ enlargement. Laboratory testing revealed severe neutropenia and elevated CRP, ERS and β2-microglobulin as well as hypergammaglobulinemia. There were no signs of anaemia and rheumatoid factor was slightly elevated. Immunophenotyping by flow cytometry revealed T-cell proliferation with LGLL phenotype. Treatment was initiated with differentsingle-agents MTX,CYCand cladribine, all of which presented unsatisfactory outcomes. After 3 years of partial but stable clinical response, the patient developed dermatologicallesions that triggered an alternative diagnosis suspicion. He underwent diagnosis reinvestigation which revealed polyclonal expansion of LGL rather than monoclonal, rescinding his previous LGLL diagnosis. Further testing revealed c-ANCA positivity although MPO and PR3 were negative. Renal function was normal and there was no evidence of pulmonary involvement.