Pathology Cheat Sheet
Iron: Move, Store, Compare
Iron deficiency and microcytic anaemia for NEET-PG: ferritin, TIBC, hepcidin, ferroportin, pencil cells, chronic disease, thalassaemia, and ring sideroblasts.
MedNext Academy | 3 min read
Iron: Move, Store, Compare
Iron deficiency and microcytic anaemia for NEET-PG: ferritin, TIBC, hepcidin, ferroportin, pencil cells, chronic disease, thalassaemia, and ring sideroblasts.
Iron metabolism and its regulation, and the causes, stages and morphology of iron deficiency and other microcytic anaemias.
High-yield lines
- Iron deficiency is the most common cause of anaemia worldwide and produces a microcytic hypochromic picture.
- Iron deficiency shows low serum ferritin, low serum iron, high total iron-binding capacity, and low transferrin saturation.
- Serum ferritin below about 12 nanograms per millilitre confirms iron deficiency in the absence of inflammation.
- Ferroportin is the only iron export channel and is the target of the regulatory hormone hepcidin.
- Hepcidin rises in inflammation and traps iron in macrophages, which underlies anaemia of chronic disease.
- Transferrin transports ferric iron in plasma, and its synthesis rises in iron deficiency, raising total iron-binding capacity.
- Ferritin is soluble readily mobilised storage iron, while hemosiderin is insoluble aggregated storage iron visible on H&E.
- The peripheral smear in iron deficiency shows microcytosis, hypochromia, pencil cells, and a raised red cell distribution width.
- Storage iron is depleted first in iron deficiency, followed by falling serum iron and then falling haemoglobin.
- Anaemia of chronic disease shows low serum iron with normal or high ferritin due to hepcidin-mediated iron sequestration.
- Thalassaemia trait shows microcytosis with a normal or raised red cell count and normal iron stores.
- Sideroblastic anaemia shows ring sideroblasts with iron-laden mitochondria encircling the erythroblast nucleus.
Mapped competency codes
- PA14.1
- PA14.2
- PA14.3
Continue into the full chapter
This summary maps to PA14-microcytic-anemia.
Frequently Asked Questions
What are the iron study findings in iron deficiency anaemia?
Low serum ferritin, low serum iron, high total iron-binding capacity, and low transferrin saturation, with absent marrow iron on Perls stain.
How does anaemia of chronic disease differ from iron deficiency?
Both show low serum iron, but chronic disease has normal or high ferritin because hepcidin traps iron in macrophages, whereas iron deficiency has low ferritin.
What is the role of hepcidin in iron homeostasis?
Hepcidin degrades ferroportin, reducing iron absorption and release from macrophages, so its rise in inflammation causes anaemia of chronic disease.
What are ring sideroblasts?
Erythroblasts with iron-laden mitochondria arranged as a collar around the nucleus, seen in sideroblastic anaemia on Perls staining.
Continue reading
Cheat SheetsAll Pathology cheat sheets
Browse the complete authored set for this subject.
Open the complete revision pathway
Explore clinician-written learning resources, structured revision and practice across the MedNext platform.
Open in the MedNext appSee plans

