Hematologic Manifestations of Constitutional Trisomy 8 Mosaicism: Two Cases and a Systematic Review of Cytogenetically Confirmed Patients.

Constitutional trisomy 8 mosaicism (CT8M) is a rare chromosomal disorder associated with congenital anomalies and hematologic malignancies, although its hematologic spectrum remains poorly defined. We report two institutional cases and performed a systematic review restricted to patients with trisomy 8 confirmed in both hematopoietic and non-hematopoietic tissues. Among 61 patients, hematologic abnormalities ranged from macrocytosis and cytopenias to dysplastic bone marrow changes and malignancies. No clear age-dependent peak of transformation emerged. Our findings suggest that CT8M represents a lifelong state of mosaic hematopoiesis with variable hematologic manifestations and uncertain malignant potential.