A 75 yrs. old male patient was admitted to the hospital for severe pancytopenia (Figure 1) (Hb- 7.7 g/dl, WBC count – 1.63 x10³ cells/uL, Platelet count – 120 x10⁹ /L and normal RBC indices). Supravital staining (New Methylene blue) of peripheral blood, performed to evaluate the reticulocyte count, unexpectedly demonstrated characteristic golf ball inclusions (HbH inclusions) (Figure 2). These were around 4% of the total RBCs. The patient and his family had no history of thalassemia. Current HPLC was also found to be normal (Figure 3).

On the basis of these findings, bone marrow studies were performed which showed significant dysplasia in erythroid and megakaryocytic lineage (Figure 4 & 5). Perl’s (iron) stain revealed presence of 9% ringed sideroblasts (Figure 6).  FISH was positive for del20q (89 %) consistent with MDS (Figure 7). Karyotyping also revealed 46, XY,del(20)(q11.2) in all the 20 metaphases (Figure 8).

In view of presence of HbH inclusions on supravital stain and Myelodysplastic features on bone marrow studies, a diagnosis of ATMDS (Alpha Thalassemia Myelodysplastic Syndrome) was made.

In recent years’ significance of supravital stains has been undermined with many laboratories switching to flow cytometry evaluation of reticulocyte count. This case of ATMDS with normal Red Cell Indices was serendipitously discovered on a supravital stain, reiterating the significance of these stains. Also it becomes essential to perform an independent evaluation for HbH inclusions with supravital stains, when a diagnosis of ATMDS is suspected based on indicative red cell indices. 

Published literature reveals that acquired α-thalassemia most commonly develops in patients with MDS, though has also been reported in association with ALL, myelofibrosis, essential thrombocythemia, and de novo AML ⁽¹⁾.

Reference:

1.    David P. Steensma, Richard J. Gibbons, Douglas R. Higgs; Acquired α-thalassemia in association with myelodysplastic syndrome and other hematologic malignancies. Blood 2005; 105 (2): 443–452. doi: https://doi.org/10.1182/blood-2004-07-2792