Acute Thymic Involution

Acute Thymic Involution

Jessica M. Comstock, MD

This thymus at low power shows the classic “starry sky” appearance of acute thymic involution. The dense blue cortex (the sky) is punctuated by macrophages (the stars).

The “starry sky” appearance of acute thymic involution is caused by macrophages ingesting lymphocytes (lymphophagocytosis image). This process is caused by endogenous steroid release due to stress.



  • Thymic atrophy

  • Acquired hypoplasia


Environmental Exposure

  • Malnutrition

  • Prolonged physical or emotional stress

  • Chronic disease

Infectious Agents

  • Viral infections, especially HIV

  • Bacterial infections

  • Fungal infections

  • Chorioamnionitis

Treatment Related

  • Acute and chronic GVHD

  • Chemotherapy

  • Irradiation

  • Prolonged treatment with corticosteroids

Jul 8, 2016 | Posted by in PATHOLOGY & LABORATORY MEDICINE | Comments Off on Acute Thymic Involution
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