Highly Aggressive CD4-Positive Mast Cell Leukaemia (Leukaemic Variant) Associated with Isolated Trisomy 19 and Hemophagocytosis by Neoplastic Mast Cells: A Case Report with Challenging Experience and Review

Figure 2

BM aspirate smear (100x) showing a variety of neoplastic MCs. The majority of blasts show abundant cytoplasm and coarse giant metachromatic blasts (a). Neoplastic MCs (Type I) (A–I) with eccentric round/oval nuclei, uneven granule distribution/hypogranulation, and spindle-shaped MCs with elongated cytoplasmic projections (b). Neoplastic MCs Type II (promastocytes) (A–H) with indented, bilobed nuclei, abundant hypogranulated cytoplasm, or with coalescent granules with uneven distribution (c). There is trilineage dysplasia with macronormoblasts, giant neutrophils, and dysplastic nuclear lobulation in megakaryocytes (arrows) (d). Increased mitotic figures (e). Prominent erythrophagocytosis exhibited by neoplastic mast cells (blue arrow) and histiocytes (f).