A hematology sampler

I couldn't find a unifying theme to morning report today other than all things hematologic. Many big topics were discussed, so to avoid a post that's 12 pages long, here are a few pearls that came up with a bit more detail...

"Leukoerythroblastic picture"
Neutrophilia, nucleated RBCs, few circulating blasts.
Ddx inc severe stress, infection, sepsis.
This with teardrop cells means "myelophthisic" picture
Ddx here includes tumor invasion of marrow, myelofibrosis, granulomatous disease

WBC morphology on blood film
-Normally less than 70% PMN, less than 30% lymphocytes
-PMNs should have no more than 3 lobes. More is megaloblastic (B12, folate, thyroid, valproate, AZT, hydroxyurea, folate antagonists). Bilobed seen in Pelger-Huet (congenital defect of PMN differentiation)
-Infection is suggested by a) toxic granulations, b) bands
-Atypical lymphocyes seen in EBV (means nuclei with nucleoli)
-Auer rod seen in AML. May also see eosinophils
-Eosinophils- drugs, parasites (esp filariasis), Churg-Strauss, HES, cholesterol emboli, many others
-Basophils- adrenal insuff, malignancy
-Monocytosis- seen in MDS
-Smudge cells- seen in CLL
-Marked L shift with preserved morphology- seen in CML before transformation

Myelodysplastic syndrome

Common feature: Ineffective production of normal mature red cells.
MDS implies risk of developing AML; 20-30% of MDS pts progress to AML

Dx is suspected if 1) sx of blood disorder 2) incidental finding of cardial MDS features: a) macrocytosis, b) monocytosis, c) cytopenias in any lineage - combination of these is highly suggestive.
~80% of pts are anemic at diagnosis; 50% have Hb <100. 40% are neutropenic at dx. TCP in 30-45%. Neutropenia or thrombocytopenia may occur without anemia.


Splenomegaly causes by etiology

Hematologic:
Massive (i.e. below or across the umbilicus): Thal major
Non-massive: RBC membrane defects, hemoglobinopathies, autoimmune hemolytic anemias

Rheumatologic:
Massive: none
Non-massive: RA (felty), SLE, sarcoidosis

Infectious:
Massive: leishmaniasis, malaria, MAC
Non-massive: viral, bacterial, mycobacterial, fungal, parasitic

Congestive:
Massive: none
Non-massive: cirrhosis, venous thrombosis (portal, hepatic, splenic)

Infiltrative:
Massive: lymphomas, myeloproliferative, Gaucher's
Non-massive: lymphoma, myeloproliferative, cancer, amyloidosis, Gaucher's, Niemann-Pick, glycogen storage diseases, hemophagocytic syndrome, histiocytosis

Links:

Click here for a good review of myelodysplastic syndromes
Click here for a good hematopathology slide site from the University of Utah

Click here for a NEJM CPC of massive splenomegaly