RBC Inclusions Decoded: Diagnostic Pearls from William Aird
William Aird, Professor of Medicine at Harvard Medical School, posted on X:
”1/7
RBC INCLUSIONS
Red blood cell (RBC) inclusions: small structures with big diagnostic value. Each one points to a different process, from marrow stress to iron overload to infection. Here’s a tour, one inclusion at a time.
2/7
Nucleated RBCs: immature erythroid precursors that still carry their nucleus.
- Normally confined to the marrow (except neonates).
- In circulation, signal marrow under stress (hemolysis, hypoxia, marrow infiltration)
Think of them as a sign of the BM “pushing hard.”
3/7
Howell–Jolly bodies: small, round basophilic nuclear remnants (DNA) DNA found within circulating RBCs.
- Appear when the spleen is absent or not functioning (asplenia, hyposplenism).
- If you see them, ask about the spleen.
See here.
4/7
Basophilic stippling: numerous fine or coarse punctate, blue-purple granules (aggregates of ribosomal RNA).
- Causes include thalassemia, lead poisoning, sideroblastic anemia.
- Coarse stippling is especially associated with lead.
5/7
Pappenheimer bodies: iron-containing granules (siderotic granules) in RBCs.
- Stain positive with Prussian blue
- Seen in sideroblastic anemia, iron overload, post-splenectomy.
See here.
6/7
Intraerythrocytic parasites: malaria, babesiosis.
- Morphology varies (rings, trophozoites, schizonts, gametocytes).
- Always correlate with travel/exposure history; finding parasites in RBCs is a diagnostic emergency.
7/7
Red cell inclusions provide direct windows into pathophysiology: nuclear remnants, iron deposits, ribosomal aggregates, or pathogens. Recognizing them is a high- yield skill at the microscope.”
Stay updated with Hemostasis Today.
-
Feb 23, 2026, 18:13Fight4Hematology Supports Research and Empowers the Next Generation – ASH
-
Feb 23, 2026, 17:59Wolfgang Miesbach: Real-World Evidence of Emicizumab on Joint Outcomes in Hemophilia A
-
Feb 23, 2026, 17:56Shiny K Kajal: The Transfusion Reaction We Often Miss
-
Feb 23, 2026, 17:53Radheshyam Meher: Contributing to the Transfusion Evidence Round-Up for International Childhood Cancer Day 2026
-
Feb 23, 2026, 17:46Mahesan Subramaniam: The Physiological Impact of Anger on Immunity
-
Feb 23, 2026, 17:42Bryan Fry: First Evidence That Bothrops atrox Venom Directly Activates Human Factor VII
-
Feb 23, 2026, 17:34Bastu Odoka: Why Blood Should NOT be Left at the Bedside to ‘Warm’
-
Feb 23, 2026, 17:28Henry Burkitt: Patients Are Challenging How the Medicines Policy System Works in England
-
Feb 23, 2026, 16:50Mutaz Al‑Sabah: Interesting Webinar on FH in Women is Now Available to Watch