title: Allograft pancreas: pale acinar nodules.
abstract: Microscopic pale-staining acinar nodules were characterized in native pancreas in the 1980s under a variety of names but have been infrequently reported since. We retrospectively studied the frequency and characteristics of pale acinar nodules in allograft pancreas biopsies, as compared to a sampling of native pancreas specimens at our center. Pale acinar nodules were present in 13% (9/69) of allograft biopsies from 22% (7/32) of transplant patients, and 23% (5/22) of native pancreas surgical specimens, although more nodules per pancreas area were present in allograft needle biopsies. Acinar nodules had size of 100 to 700 μm, were periodic acid-Schiff pale, were synaptophysin negative, stained more weakly with keratin CAM 5.2 compared to surrounding parenchyma, and had a low proliferative rate. Ultrastructural evaluation revealed paucity of zymogen granules with dilated cistern-like structures. In our experience, pale acinar nodules have similar features in allograft and native pancreas specimens, yet remain of uncertain etiology and significance.
authors.affiliation: Oregon Health & Science University, Dept of Pathology L471, Portland, OR, 97239. Electronic address: megant@stanford.edu.
authors.forename: Megan L
authors.initials: ML
authors.lastname: Troxell
authors.affiliation: University of Maryland, Department of Pathology, NBW85, University of Maryland Medical Center, Baltimore, MD 21201. Electronic address: cdrac001@umaryland.edu.
authors.forename: Cinthia
authors.initials: C
authors.lastname: Drachenberg
mesh_terms: D061354:Acinar Cells / Q000737:chemistry / Q000637:transplantation / Q000648:ultrastructure*; D064591:Allografts; D015415:Biomarkers / Q000032:analysis; D001707:Biopsy, Needle; D006801:Humans; D007150:Immunohistochemistry; D007633:Keratins / Q000032:analysis; D019394:Ki-67 Antigen / Q000032:analysis; D046529:Microscopy, Electron, Transmission; D016035:Pancreas Transplantation / Q000009:adverse effects*; D046790:Pancreas, Exocrine / Q000737:chemistry / Q000601:surgery / Q000648:ultrastructure*; D012189:Retrospective Studies; D016708:Synaptophysin / Q000032:analysis; D016896:Treatment Outcome
chemical_list: D015415:Biomarkers; C400901:CAM 5.2 antigen; D019394:Ki-67 Antigen; D016708:Synaptophysin; D007633:Keratins
keywords: Acinar nodule; Allograft; CAM52; Micronodule; PASd; Pancreas