Therapy-related myeloid neoplasms (t-MN) account for approximately 10% to 20% of all cases of AML (acute myeloid leukemia), MDS (myelodysplastic syndrome) and MDS/MPN (myelodysplastic syndrome/myeloproliferative neoplasms), MDS, and MDS/MPN. In our study, we evaluated peripheral blood smear samples and hemogram values in breast cancer patients who were receiving adjuvant anthracycline regimens and were in remission.A total of 78 patients receiving anthracycline-based adjuvant chemotherapy treatment from Kayseri Research and Training Hospital and Mersin State Hospital were enrolled in the study. Their adjuvant treatments had been completed at least 18 months prior to the study.Two patients complained of anemia (2.2%) (Hb11 mg/dl), leukopenia was observed in seven patients (7.7%) (leukocytes4000/ mm(3)), and thrombocytopenia was observed in four patients (4.4%) (PLT150.000/mm(3)). In the blood smear samples, the following were observed: ovalomacrocytes (14%), macrocytes (37%), acanthocytes (1%), stomatocytes (12%), teardrops (12%), nucleated erythrocytes (1%), basophilic stippling (14%), and Howell-Jolly bodies (1%). Additionally, hypo-granulation (38%), Pelger-Huet abnormalities (26%), hypersegmentation (20%), immature granulocytes (8%), and blasts (6%) were observed. We also confirmed the presence of giant platelets (50%) and platelet hypogranulation (19%).According to the peripheral blood smear assessments in our study, we suggest that breast cancer patients should be evaluated for MDS in the early stages, starting from month 18, even if the automated blood counts are normal.Tedaviye bağlı myeloid neoplazmlar, tüm AML,MDS ve MDS/MPN vakalrının yaklaşık %10–20’sini oluşturmaktadır. Çalışmamızda adjuvant antrasiklinli kemoterapi rejimi almış remisyonda meme kanserli hastaların periferik yayma ve hemogram değerlerini araştırılmıştır.Antrasiklin bazlı kemoterapi rejimi almış ve remisyonda olan toplam 78 hasta Kayseri Eğitim ve Araştırma Hastanesi ile Mersin Devlet Hastanesi’nden çalışmaya alınmıştır. Hastaların remisyonda olması ve tedaviyi en az 18 ay once tamamlamış olmasına dikkat edildi.İki hastada anemi (%2.2) (Hb11 mg/dl), 7 hastada lökopeni (%7.7) (Lökosit4000/mmÇalışmamızın periferik yayma değerlendirme sonuçlarına gore meme kanserli hastaların myelodisplazik sendrom açısından, otomatik hemogram değerleri normal olsa da, erken dönemde, 18. aydan başlayarak rutin araştırılmasını önermekteyiz.