PMC8170141_01
Bone marrow biopsy before allogeneic SCT, showing low grade MDS with trilineage dysplasia and no obvious increase in blasts. A. Peripheral blood: Pseudo-Pelger-Huet neutrophils with hypogranular cytoplasm and hypolobated nuclei. B and C. Dysplastic megakaryocytes with nuclear hypolobation and nuclear separation. D. Dysplastic erythroid precursors with nuclear irregularity or budding. E and F. Normocellular bone marrow with relative erythroid hyperplasia, dysplastic megakaryocytes, and no obvious increase in blasts.
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Bone marrow biopsy on 11/17/2011 (Fig. 1) showed trilineage dysplasia with no obvious increase in blasts, consistent with therapy-related myeloid neoplasm.
Gastric biopsy post allogeneic SCT, showing MDS relapse as gastric myeloid sarcoma. H & E shows benign gastric mucosa with diffuse submucosal infiltrate by large atypical immature cells with fine chromatin, occasional conspicuous nuclei, and scant cytoplasm. The immature cells are positive for CD34 and myeloperoxidase, consistent with myeloblasts and the diagnosis of myeloid sarcoma.
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The gastric biopsy on 02/05/2014 (Fig. 2) showed an extensive mononuclear infiltrate which could easily be confused with lymphocytes in the setting of chronic inflammation.
Repeated gastric biopsy showing persistent myeloid sarcoma. H & E shows benign gastric mucosa with diffuse submucosal infiltrate of large atypical immature cells with fine chromatin, occasional conspicuous nucleoli, and scant cytoplasm. The immature cells are positive for CD34 and CD117, consistent with myeloblasts and the diagnosis of myeloid sarcoma.
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Repeated EGD and gastric biopsies on 05/30/2014, 11/14/2014, and 07/30/2015 (Fig. 3) showed persistent erythema and myeloid sarcoma, while corresponding bone marrow biopsy showed no signs of MDS, AML, or CLL/SLL, in morphology, immunohistochemical studies, flow cytometry, or cytogenetic studies (Fig. 4).