Noncrystallized form of immunoglobulin-storing histiocytosis as a cause of chronic lung infiltration in multiple myeloma

Abstract 

A 52-year-old man, with a known case of multiple myeloma, developed chronic bilateral pulmonary infiltration. Open lung biopsy displayed desquamated interstitial pneumonia-like pattern characterized by diffused patchy intra-alveolar accumulation of unusual macrophages containing abundant round intracytoplasmic eosinophilic globular structures 1-7 μm in size. The globules were stained positively with restriction for κ light chain by immunoperoxidase study. Electron microscopic examination revealed amorphous substances without a crystalline shape or fine ultrastructure of lattice or linear parallel configuration, indicating storage of noncrystallized immunoglobulin. The current report documented, for the first time, the noncrystallized form of immunoglobulin-storing histiocytosis, causing an unusual pulmonary pathology in a patient with multiple myeloma.

Keywords: Pulmonary, Immunoglobulin-storing histiocytosis, Multiple myeloma