A Follow-Up Case of Breast Carcinoma with the Unusual Visitor in Peripheral Blood: Unlock Feathered Edge Secret

Background: Breast cancer is the most common cancer in women worldwide and in India. There are very few cases of breast cancer with peripheral blood dissemination having acute leukaemia-like blast cells. Case presentation: Here we present a 44-year-old breast cancer follow-up patient with the presence of leukaemia-like blast cells in peripheral blood. The specific cytochemical staining and immunophenotyping assays on bone marrow biopsy revealed that atypical cells in her peripheral blood were from breast cancer metastasis. A comprehensive workup confirmed carcinocythemia in the present case and systemic chemotherapy and hormonal therapy were planned. However, she died 15 days after the carcinocythemia presentation. Carcinocythemia patients have a poor survival. Conclusion: Because carcinocythemia cells can mimic leukemic blasts and share morphological features, the patient's medical history and a careful analysis of the feathery border of the smear are needed to make a definitive diagnosis.