Byline: Manish. Singh, Ruchi. Gupta, K. Surabhi, Khaliqur. Rahman

Sir,

Auer rods are crystalline inclusions, pathognomic of myeloid differentiation of the leukemic blasts. Their presence in maturing myeloid cells and monocytes is rare. They have primarily been described in patients with acute promyelocytic leukemia (APL) and other French-American-British (FAB) subtypes of acute myeloid leukemia (AML), namely AML- M1, M2 and M4. We would like to document a case of AML-M2 with eosinophilia, where numerous polymorphs showed presence of Auer rods.

A 10-year-old male, born of nonconsanguineous marriage, presented to us with high-grade fever, loss of appetite and generalized weakness of 10 day's duration. Physical examination revealed moderate pallor and presence of submandibular lymph node measuring approximately 2 cm in maximum dimension. Complete hemogram showed hemoglobin of 73 g/L, total leucocyte count of 10.3 x 10 [sup]9 /L, platelet count of 29 x 10 [sup]9 /L and smear examination revealed 16% blasts, some of which contained Auer rods. Bone marrow aspiration smears were cellular and showed approximately 53% blasts, along with maturing myeloid series of cells and 8% eosinophils. Auer rods were noted in some of the neutrophils and myelocytes [Figure 1]. In addition, significant dysplasia was noted in the mature myeloid cells in the form of Pseudo-Pelger-Huet anomaly and hypogranulation [Figure 1]. On flow cytometry, theses blasts were positive for CD34, CD117, HLA-DR, CD13, cMPO and also showed aberrant expression of CD19. Interestingly these cells...