6 June 2011 (Monday) - Iron Deficiency
The nice people over at Medical Laboratory And EQAS News run a survey every Sunday. Yesterday’s was a blood film (pictured above) from “44 years old male from Murmansk, North Russia has been feeling very weak and tired during last two months. He is working as timberjack, but has been unemployed lately.”
RBC: 4.28 (Low)
HGB: 9.7 (Low)
HCT: 29.9 (Low)
MCV: 69.7 (Low)
MCH: 22.6 (Low)
MCHC: 32.4 (Low)
RDW: 18.4 (High)
What is your suggestion for diagnosis? And what (one) further test should be performed?
I got the correct answer for the first section: Severe iron deficiency anaemia. Severe hypochromasia, microcytosis, pencil-shaped cells, low haemoglobin, low haematocrit and high RDW are typical for iron deficiency anaemia.
This was relatively straight forward. There was really only one possible diagnosis – iron deficiency. Bearing in mind the patient leads a very active life as a timberjack and has only recently become ill, the only other possible cause of this blood count (thalassaemia with blood loss) is unlikely as thalassaemia is a life long malady.
The further testing wasn’t quite so straight forward. Obviously to confirm the iron deficiency, it would be a good idea to check body iron store. Low ferritin and high TIBC support the iron deficiency. However only being given one choice of test made it difficult. Ferritin or TIBC? Personally I went for ferritin, which was the majority decision.
But it wasn’t much of a majority. Only 31% plumped for this. More people wanted to assess B12 & folate levels than wanted to measure the TIBC. What on Earth were they thinking of? And interestingly 9% of the respondents thought the case was thalassaemia major. (!??!?!?!)
The expert opinion given went on to say that “Sometimes blood cell count and smear findings can be quite similar in thalassemia minor. If the findings are unclear, haemoglobin electrophoresis would be relevant to exclude thalassemia minor.” I’ll grant that microcytosis is common between iron deficiency and thalassemia minor. But iron deficiency causes an anaemia, thalassemia minor does not. In fact an erythrocytosis is a more common finding in thalassemia minor. The pencil cells evident in iron deficiency are not seen in thalassemia minor; target cells are. And how does haemoglobin electrophoresis exclude thalassaemia? A haemoglobinopathy would certainly be excluded, but not a thalassaemia.
Labels: on-line morphology