A 58-year-old woman comes to the physician because of progressive generalized weakness over the last two months. Two weeks ago, she woke up with a nosebleed that stopped after applying pressure to her nostril. She has had no other bleeding events. She was diagnosed with early stage breast cancer 6 years ago and underwent surgery and adjuvant combination chemotherapy with doxorubicin, cyclophosphamide, and paclitaxel. She underwent gastric bypass surgery two years ago. Her other medical problems include depression and gastroesophageal reflux disease. She takes paroxetine, omeprazole, and calcium and vitamin D supplements. She had smoked 1 pack of cigarettes daily for 12 years, but stopped after her diagnosis of breast cancer.
Her blood pressure is 112/70 mm Hg and pulse is 89/min. Her BMI is 30 kg/m². Cardiopulmonary examination is normal. Breast examination shows a well-healed scar over the left breast. The abdomen is soft and non-tender and there is no organomegaly. There are no skin rashes.
Laboratory results are as follows:

The peripheral smear reveals no platelet clumping but does show polychromasia; occasional nucleated red blood cells; metamyelocytes; and cells with large nuclei, prominent nucleoli, and scant cytoplasm. There are no schistocytes.
This patient's current condition is most likely related to which of the following?

Question

A 58-year-old woman comes to the physician because of progressive generalized weakness over the last two months. Two weeks ago, she woke up with a nosebleed that stopped after applying pressure to her nostril. She has had no other bleeding events. She was diagnosed with early stage breast cancer 6 years ago and underwent surgery and adjuvant combination chemotherapy with doxorubicin, cyclophosphamide, and paclitaxel. She underwent gastric bypass surgery two years ago. Her other medical problems include depression and gastroesophageal reflux disease. She takes paroxetine, omeprazole, and calcium and vitamin D supplements. She had smoked 1 pack of cigarettes daily for 12 years, but stopped after her diagnosis of breast cancer.
Her blood pressure is 112/70 mm Hg and pulse is 89/min. Her BMI is 30 kg/m². Cardiopulmonary examination is normal. Breast examination shows a well-healed scar over the left breast. The abdomen is soft and non-tender and there is no organomegaly. There are no skin rashes.
Laboratory results are as follows:

The peripheral smear reveals no platelet clumping but does show polychromasia; occasional nucleated red blood cells; metamyelocytes; and cells with large nuclei, prominent nucleoli, and scant cytoplasm. There are no schistocytes.
This patient's current condition is most likely related to which of the following?

Quizplus · Accepted Answer

This patient's peripheral smear shows cells with large nuclei, prominent nucleoli, and scant cytoplasm, findings that are suggestive of immature cells (i.e., myeloblasts). Given the associated severe thrombocytopenia and leukocytosis, acute myeloid leukemia is the most likely diagnosis. Individuals exposed to chemotherapeutic agents are at risk for developing myelodysplastic syndrome (MDS), mixed myelodysplastic/myeloproliferative neoplasms (MDS/MPN), and acute myeloid leukemias (AML). Approximately 10-20% of all cases of these hematologic diseases are therapy related. The incidence varies according to the specific chemotherapeutic agents, time of exposure, and dosing. Anthracycline-induced leukemia classically presents 5 -10 years post-treatment with a preceding MDS phase. Unfortunately, compared to de novo leukemias, therapy-related leukemias respond poorly to current treatment options (e.g., chemotherapy and/or allogeneic hematopoietic stem cell transplantation). (Choice B) Bone metastasis is present in 60-80% of patients with metastatic breast cancer. A serologic marker suggestive of bone metastasis is an elevated alkaline phosphatase, which is not present in this patient. In this patient, the peripheral smear findings are more consistent with myeloid leukemia. (Choice C) Malabsorption can present with macrocytic anemia due to vitamin B₁₂ and other nutrient deficiencies. However, this patient's normal MCV and presence of metamyelocytes and myeloblasts makes malabsorption less likely. ₁₂ (Choice D) This patient's normal range bilirubin and peripheral smear without schistocytes make microangiopathic anemia less likely. (Choice E) Paraneoplastic syndromes in breast cancer include cerebellar degeneration, development of scleroderma, SLE, nephrotic syndrome, and leukemoid reactions. However, this patient's hematologic findings (e.g., thrombocytopenia, anemia) are more suggestive of a primary hematologic process rather than a paraneoplastic syndrome. Educational objective: Individuals exposed to chemotherapeutic agents are at risk for developing myelodysplastic syndrome (MDS), mixed myelodysplastic/myeloproliferative neoplasms (MDS/MPN), and acute myeloid leukemias (AML). __________ References: Therapy related myeloid leukemia (http://www.ncbi.nlm.nih.gov/pubmed/18692692) Etiology and management of therapy-related myeloid leukemia. (http://www.ncbi.nlm.nih.gov/pubmed/18024664)

A 58-Year-Old Woman Comes to the Physician Because of Progressive