Crystal-Storing Histiocytosis: An Important Cytology Cue for Diagnosis of a Lymphoproliferative Process

Crystal-storing histiocytosis (CSH) is a rare manifestation of a B-cell lymphoproliferative process characterized by intrahistiocytic accumulation of crystallized immunoglobulin involving multiple body sites. We report a case of localized CSH with marginal zone lymphoma (MZL) involving a retroperitoneal lymph node at the left renal hilum. The patient was a 77-year-old man who had hematuria in 2008. On ultrasonography, nephrolithiasis …