Case presentation.
A 90-year old gentleman was admitted to our hospital with symptomatic
microcytic anemia and a swollen left leg. His pertinent past medical
history included atrial fibrillation for which he was anticoagulated
with rivaroxaban. His hemoglobin on arrival was 63 g/L with an MCV of 70
fL showing biochemical evidence of iron deficiency. At the same time,
his complete blood count (CBC) was notable for marked thrombocytosis
(2114 x 109/L) and neutrophil predominant leukocytosis
(16.3 x 109/L). Circulating blasts were not flagged.
An ultrasound of his lower limbs demonstrated two hematomas within the
left calf measuring 10.7 x 4.9 x 1.7 cm and 12.5 x 6.0 x 3.0 cm
respectively (Figure, panel A, posterior and medial complex fluid
collection (yellow arrows) consistent with a hematoma is seen). As well,
imaging evidence of chronic deep vein thromboses in the right and left
popliteal veins was present (Figure, panel B, right popliteal vein (red
arrow) demonstrating circumferential thickening (yellow arrows)
consistent with thrombus formation is shown). Upper and lower endoscopic
assessment demonstrated no evidence of bleeding and testing for acquired
von Willebrand disease was within normal limits. Given his anemia and
hematomas, his anticoagulation was held. He was subsequently treated
with packed red cell transfusion and IV iron sucrose infusion. In lieu
of the degree of thrombocytosis which was not in keeping with hemorrhage
or iron deficiency, in addition to dysplastic features on peripheral
blood film review, a bone marrow biopsy was requested and performed. The
aspirate showed morphologic evidence of dyserythropoiesis such as
normoblasts with irregular nuclear contours, multinucleated precursors
and presence of ring sideroblasts (Figure, panels C-D and I x 50
magnification; please see black arrows). Presence of
hypogranular/pelgeroid granulocytes and frank micromegakaryocytes
provided evidence of multilineage dysplasia (Figure, Panels C-E).
Extremely large multinucleated megakaryocytes (so called “staghorn”
type) that exhibited loose cellular association in aggregates, were some
myeloproliferative features as identified by trephine hematoxylin and
eosin (H&E) and cluster of differentiation 61 (CD61; figure, panels F-H
x 50 magnification). Further ancillary testing demonstrated a normal
male karyotype as well as mutations in genes ASXL1, DNMT3A, SF3B1and JAK2 facilitating the diagnosis of MDS/MPN-RS-T. Upon
radiographic stabilization of his hematoma, anticoagulation was
reinitiated. At discharge the patient was treated with 500 mg P.O. daily
hydroxyurea resulting in reduction in his platelet count to 686
x109/L two weeks post his admission. He remains stable
in the community on this same dose of hydroxyurea.
Discussion .