Transcription
Hey médicos, is perfection, Alice viewers. How are you doing today? Now, since we have discussed macrocytic anemia, especially the megaloblastic subtype, now let's talk about non-megaloblastic macrocytosis. And of course, since it's macrocytic, the mean corpuscular volume will be increased. The symptoms of anemia are the same no matter what: tired and pale, pale and tired. Sometimes, I get an aura, and I could also have a murmur and also some headache and exercise intolerance, depending on MCV. The anemia is either microcytic (small cells), normocytic (normal-sized cells), or macrocytic (large cells). Macrocytic anemia will have an MCV of more than 100 fL.
Macrocytic anemia has two subtypes: megaloblastic and non-megaloblastic. What's the difference? Megaloblastic is a process with hypersegmented neutrophils, pancytopenia, and maybe even indirect hyperbilirubinemia. Non-megaloblastic: no hypersegmented neutrophils, no pancytopenia; usually, white blood cells and platelets have a normal number. And also remember that megaloblastic can have causes in both folate and B12; maybe more with B12. Neuropathy is exclusively B12 here; no glossitis and no neuropathy here. The cells are big and oval here; they are rounded but big, like big and rounded. So, non-megaloblastic, but they are still macrocytic. These are the main differences.
What's the most common cause of megaloblastic? Folate is usually more common. Why is that? Your liver only stores folate for months; it stores B12 for years, can be up to nine years, which is great. Here, the most common causes are alcoholism—this is the most common one—also, you have liver disease and drugs as causes of non-megaloblastic. So, in liver disease, you will have MCV, of course, high, around 105. In liver disease, you will see these target cells. Why are they target? There is excessive membrane lipids that's elevating the RBC's like this, and it's caused this kind of target lesion. Remember, this is three-dimensional, like in real life; I cannot draw it here anyway. So, target cells are there in liver disease. The lifespan of RBCs is not decreased; they are just big red blood cells like this.
In non-megaloblastic anemia, sometimes you don't have anemia—like, symptoms of anemia are not there; you just have big RBCs, but you're you're fine; just the RBCs are big. How about alcoholism? Usually, the MCV is around like 110, or maybe 100 to 110—like, still macrocytic. You have something called vacuolation of the precursors of RBCs, which like have many vacuoles, and these are present in the bone marrow, of course. The precursors stay in the bone marrow. Is alcoholism reversible? Yes, if you stop drinking alcohol, these macrocytosis or big cells will eventually disappear. So, you can reverse the macrocytosis, and you can reverse the anemia by stopping drinking alcohol. So, for hematology sake, stop drinking excessively.
Here are the main differences between megaloblastic and non-megaloblastic. I'll see you in the next video when we will talk about the normocytic anemia, big-time for the boards. So take care, and study hard, and be fine.