Successful surgical treatment for pulmonary crystal-storing histiocytosis following the onset of gastric non-hodgkin lymphoma.

Crystal-storing histiocytosis is a rare clinical entity characterized by an increase in the number of abnormal histiocytes accompanied by accumulation of crystallized immunoglobulins. We describe the case of an 80-year-old man who presented with crystal-storing histiocytosis of the lung 13 years after receiving a diagnosis of gastric non-Hodgkin lymphoma (NHL ; clinical stage, Lugano IA). After wedge resection of the left upper lobe, the histological findings showed crystal-storing histiocytosis with CD68(+), some small to medium lymphoid cells with CD79a(+) with κ(+(weekly)) and λ(-), and some plasma cells with CD138(+), and rearrangement of the immunoglobulin heavy chain. Based on the nonrecurrent gastric NHL, small B-cell population, and failure to detect the same clone by polymerase chain reaction analysis, our case was classified as pulmonary localized crystal-storing histiocytosis without underlying lymphoproliferative or plasma cell disorder. The findings of minor B-cell populations harboring a heavy chain rearrangement with slight light-chain restriction (κ > λ) may be related to the pathogenesis of crystallogenesis and crystal-storing histiocytosis. Moreover, surgical treatment may be an effective therapeutic option for solitary crystal-storing histiocytosis.