title: A comparison of the ultrastructure of pigment granules in melanosis ilei and pulmonary lymph nodes.
abstract: Two cases of melanosis ilei were studied, in which grossly visible blackish pigmentation of the ileal mucosa was incidentally discovered at autopsy. Light microscopy showed that the pigment granules lay within macrophages in atrophic Peyer's patches. Ultrastructural studies showed that the pigment granules were heterolysosomes containing crystalline material, particles, granules and, occasionally, lipid droplets. The morphological similarity between these pigment granules and granules in pulmonary macrophages was established through ultrastructural studies of pulmonary lymph nodes obtained during routine autopsies. These data, plus results of past electron-probe X-ray analytic studies by us and others, leads us to conclude that the pigment granules in melanosis ilei contain exogenous material derived from inspired and ingested materials.
authors.affiliation: Canadian Reference Centre for Cancer Pathology at The Ottawa Civic Hospital, Canada.
authors.forename: F N
authors.initials: FN
authors.lastname: Ghadially
authors.forename: S A
authors.initials: SA
authors.lastname: Boone
authors.forename: V M
authors.initials: VM
authors.lastname: Walley
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D007077:Ileal Diseases / Q000473:pathology*; D007082:Ileum / Q000648:ultrastructure*; D008168:Lung / Q000648:ultrastructure*; D008198:Lymph Nodes / Q000648:ultrastructure*; D008548:Melanosis / Q000473:pathology*; D008854:Microscopy, Electron; D008875:Middle Aged; D010860:Pigments, Biological
chemical_list: D010860:Pigments, Biological