This is a 72-year-old female who was treated for esophageal carcinoma with chemoradiation and surgery. After a period of 9 years, she presented with pancytopenia. Peripheral smear at the time revealed pancytopenia, anisopoikilocytosis and occasional dysplastic hypo-granular neutrophils, prompting the need for Bone marrow studies. Bone marrow aspirate smears and biopsy were notable for multilineage dysplasia with <20% blasts, establishing the diagnosis of therapy-related myeloid neoplasm. However, no abnormality was identified on cytogenetic studies and molecular studies did not identify any pathogenic mutations. 

Learning points 

1. Cytopenia in patients with remote history of therapy with cytotoxic agents/radiation warrants careful recognition for dysplastic cells/blasts in the blood/marrow as therapy related myeloid neoplasm (t-MN) occurs as a late complication in such cases.  
2. Although, these cases may be categorized as t-AML, t-MDS or t-MDS/MPN according to the number of blasts on bone marrow, they are essentially considered as single disease entity because blast percentage is not as prognostically important as in de-novo myeloid neoplasms. 
3. Most t-MN cases with prior exposure to alkylating therapy/ionizing radiation are typically associated with: 

            - 5-10 years of latency period 

            - prior MDS phase 

            - Unbalanced loss of genetic material (often involving chromosome 5 &/or 7), complex karyotypes and mutation/loss of TP53 (associated with poor survival).  

However, no cytogenetic abnormality is found in rare cases.