Pulse/hyaline ring granuloma revisited: etiologic role of seed-derived storage cells

The objectives are to precisely identify the cells that incite the formation of lesions that are generally known as “pulse granuloma” or “hyaline ring granuloma” that occur mostly in the oral cavity, in the lungs, in and around the gastrointestinal tract, and other sites, and to suggest an alternative name for these lesions that accurately reflects their etiology. Critical review of the medical and dental literature was undertaken, and the microscopic appearances of granuloma-inciting cells depicted in the literature and seen in our practices were compared with seeds and their contents originating from a variety of leguminous and non-leguminous plants. Sections of selected seeds were examined microscopically before and after digestion with saliva and alpha amylase and subsequent routine processing and staining with H&E, PAS, and iodine. Pre- and post-digestion slides were examined with polarized light. The morphology of the granuloma-inciting cells is identical to the storage cells present in seeds from a variety of leguminous and non-leguminous plants. The cells that trigger the formation of “pulse granulomas”/“hyaline ring granulomas” are storage cells that are derived from ingested seeds of leguminous and non-leguminous plants. The terms “pulse,” “legume,” and “lentil,” which have been applied to these cells, are misnomers. Our findings indicate that the terms “pulse granuloma” and “hyaline ring granuloma” are not appropriate descriptors of these lesions. We recommend that they be replaced by “seed storage cell granuloma,” a term that now accurately reflects the etiology of these lesions.