6 had NHL; (#) Giant
pronormoblast (Lantern cell) Seen; (##) atypical maculopapular rash over both lower limbs Table II.
(14) The infected erythroid precursors suffer arrest of maturation beyond the normoblast stage leading to the formation of giant
pronormoblasts in the bone marrow and peripheral reticulocytopenia.
Until POD 5, 7, and 14, postoperative Hgb and Hct levels were not significantly different among the three groups, possibly related to the maturation cycle of
pronormoblasts. In patients with substantial loss of erythrocytes, proliferation and differentiation of more bone marrow
pronormoblasts may be initiated.
In pure red cell aplasia giant
pronormoblasts in the marrow are considered pathognomonic.
There are characteristic morphological features on the bone marrow biopsy such as red-cell maturation arrest and giant
pronormoblasts, but the bone marrow biopsy is not required for diagnosis.
Bone marrow examination shows normocellularity with findings of profound depletion of erythroid cells, abnormal very large
pronormoblasts and normoblasts exhibiting intranuclear eosinophilic inclusion bodies (Lampion or Lantern cells).