A rare cell with both eosinophilic and basophilic granules

While running a routine cell image check we stumbled across this odd looking cell. Among all the thousands of cells we have in our digital cell library this was the only one looking like this. For us this was quite a rare finding.

Have you seen cells looking like this?

15 thoughts on “A rare cell with both eosinophilic and basophilic granules”

    1. Correction on my previous comment. This Harlequin Cell you can see in AML with chromosome 16 conversion.

  1. I see many of these cells in my female case today ( Female patient, 42 years, complaining of generalized weakness, pallor, mild fever, and moderate anemia, she had RA, and she is repeated blood transfusion.
    Examination: revealed hepatosplenomegaly, no LN enlargement.
    CBC shows moderate NN anemia (Hb 7.5 gm/dl) WBCs 2.9 x109/ L, platelets are 230 x 109/L, retics 1.5%, ESR 70 mm, AST 16, ALT 20
    HCV negative, HBV negative
    BM: normocellular, with normal erythroid & megakaryocytic serious, the myeloid serious show mild eosinophilia and most of esionophils and myelocytes show (cell with both eosinophilic and basophilic granules).
    I think this may be hybrid cell, we need to do myeloperoxidase stain and to take a detailed drug history, and to access the cause of eosinophilia and anemia, then we can do inv(16)

    1. Most probably it is AML_M4E class leukemic, subclass of AMML with eosinophilia. In this condition eosinophils shows large basophilic granules, confirm with ASD chloroacetate esterase.

  2. I have seen several times such cells in different clinical conditions.These granules were negative for Toluidine stain and are most likely proeosinophilic.

  3. Further to Margit Grome’s quotation from Blood Cells, these dark granules are proeosinophilic granules. As well as seeing them in various haematological neoplasms, you can also see them in reactive eosinophilia. the distinctive thing in AML associated with inv(16) is that the darkly staining granules tend to be rather large. These are usually NOT hybrid cells showing lineage infidelity.

    1. I observe such cells with large darkly staining granules in occasional patients while karyotyping myeloid neoplasms with GTG banding.
      In what percent of cases would FISH for inversion 16 be positive?
      Recently I observed one cell with dark and pale/watery stained granules. Would this suggest eosinophilic and basophilic granules?

  4. A nice example of lineage infidelity as seen in such things as CML. I had not heard them described as Harlequin cells before, but i quite like this (although not to be confused with the skin condition).

  5. Also known as a “Harlequin” cell. These are eosinophils with atypical basophillic staining granules. We see these most commonly in CML.

  6. This cell is abnormal eosinophil. Seen commonly in Acute myelo-monocytic leukemia with Eosinophilia (M4-Eos.) (Inv.16).

  7. We see them once or twice a year. So they are rare. We call them eosinophils – and if there is more than one, we will comment.
    In Blood Cells – (by Barbara J. Bain) it says: ” In acquired disorders of granulopoiesis it is not uncommon to see eosinophils in which some granules have basophilic staining characteristics. These are immature granules, sometimes termed ‘Pro-eosinophilic granules*. Such cells are increased in frequency in CGL, eosinophilic leukaemia and certain categories af AML, in which eosinophils are part of the leukaemic clone, particularly cases of AMML with eosinophilia associated with inversion of chromosome 16.”…. “But recent evidence has shown, that in some patients with CLG there are also hybrid cells with a mixture of granules of eosinophil type and baosphil type.” Nice photo – thank You very much.

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