Acute thymic involution

Author: Hanni Gulwani, M.D. (see Authors page)

Revised: 14 June 2018, last major update December 2012

Copyright: (c) 2003-2018,, Inc.

PubMed Search: Acute thymic involution

Cite this page: Gulwani, H. Acute thymic involution. website. Accessed July 21st, 2018.
Definition / general
  • Due to stress (chronic debilitating disease), HIV or other infections, prolonged protein malnutrition and immunosuppressive or cytotoxic drugs, graft versus host reaction
  • Seen in newborn infants with chorioamnionitis and sepsis
  • Thymus size is significantly reduced in preterm infants born to mothers with subclinical, histologically proven chorioamnionitis (Hum Pathol 2000;31:1121)
Microscopic (histologic) description
  • Preservation of lobular architecture and Hassall corpuscles but marked lymphocyte depletion (particularly with HIV)
  • Vessels are large compared to size of lobules
  • Frequent plasma cells, fibrohyaline changes of basement membrane of vessels and thymic epithelium
  • HIV patients also have effacement of corticomedullary junction and inconspicuous Hassall corpuscles
Differential diagnosis