Crystal-storing histiocytosis and extranodal marginal zone lymphoma of the lung in a child with common variable immunodeficiency

Crystal-storing histiocytosis (CSH) is a proliferation of histiocytes with intracellular accumulation of crystallized immunoglobulins that may accompany benign and malignant plasma cell proliferations, including marginal zone lymphoma. We report here the first case of CSH of the lung in a child with common variable immunodeficiency (CVID). A 12-year-old girl with CVID presented with fever, shortness of breath, hypoxemia, and mental confusion. She had multiple bilateral lung nodules and extensive mediastinal lymphadenopathy. A wedge biopsy of the lung showed a well-demarcated nodular mass composed of proliferation of large histiocytes with bright eosinophilic cytoplasm replacing the lung parenchyma. In addition, there was a peribronchiolar and perivascular lymphoid infiltrate composed of kappa light chain-restricted small lymphocytes, plasmacytoid lymphocytes, and plasma cells. The B cells were negative with CD5 and CD10 and expressed CD43. We review the pathogenesis of pulmonary marginal zone lymphoma of CVID patients and discuss its association with CSH.