title: Retained fetal adrenal cortex in a cynomolgus macaque (Macaca fascicularis).
abstract: An incidental, bilateral, retained fetal adrenal cortex was detected in a male cynomolgus macaque (age, approximately 2.4 y) used in a 4-week toxicology study. Microscopic examination of the adrenal gland cortex zone revealed the presence of additional solid sheets and columns of cells supported by vascular capillary bed and composed of large polyhedral cells with abundant eosinophilic, slightly finely vacuolated cytoplasm that surrounded the entire circumference of the medulla. Nuclei were vesicular, round to oval with prominent small nucleoli. There was no evidence for inflammation or cellular degeneration. Based on the microscopic examination, a diagnosis of retained fetal cortex of the adrenal gland was made. This morphologic change resembles fetal cortex in human infants. To our knowledge, this case description is the first report of a cynomolgus macaque with the rare entity of retained fetal cortex, which should not be misinterpreted as a test article-related change.
authors.affiliation: Pfizer Worldwide Research and Development, Drug Safety Research and Development, 1 Burtt Road, Andover, MA 01810, USA. Electronic address: Zaher.Radi@Pfizer.com.
authors.forename: Zaher
authors.initials: Z
authors.lastname: Radi
authors.affiliation: Pfizer Worldwide Research and Development, Drug Safety Research and Development, 10646 Science Center Drive, San Diego, CA 92121, USA.
authors.forename: Mark
authors.initials: M
authors.lastname: Evans
mesh_terms: D000302:Adrenal Cortex / Q000196:embryology / Q000473:pathology*; D000307:Adrenal Gland Diseases / Q000473:pathology* / Q000662:veterinary*; D000818:Animals; D008252:Macaca fascicularis; D008297:Male
keywords: Adrenal gland; Cynomolgus macaque; Histopathology; Retained adrenal cortex; Toxicology