PMC6479101_01
On MRI, a lesion measuring 5 x 3 cm in left temporal region eroding the underlying bone.
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The lesion showed intense contrast enhancement with underlying bone erosion and involving the left cerebellopontine angle (Fig. 1).
FNAC revealing small, blue, round cells forming rosettes at places (Leishman, 40x).
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Fine needle aspiration cytology (FNAC) of the mass was performed which showed small, uniform, blue, round cells which at places were forming rosettes (Fig. 2).
A-C: Myeloid blasts infiltrating the muscles (H & E, A-40x, B-200x, C-400x).
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Fair number of typical and atypical mitosis was also seen (Fig. 3A-C).
A-D: Tumor cells are positive for MPO, CD34, CD117 and negative for myogenin (200x).
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HLA DR and negative for LCA, CD 20, CD3, CD 10, CD 56, Tdt, CK, NB84 and synaptophysin (Fig. 4A-D). Myogenin and Desmin were negative ruling out possibility of rhabdomyosarcoma. Histopathological diagnosis of myeloid sarcoma was made.
Peripheral blood film demonstrating myeloid blasts with abundant cytoplasm.
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At that time peripheral blood examination revealed 90% atypical cells/blasts conforming to morphology of myeloid blasts (Fig. 5).