Cyclin-Dependent Kinase 4/6 Inhibitor (Palbociclib) Induced Aplastic Anemia in a Patient with Metastatic Breast Cancer.

Breast cancer is the most common cancer diagnosed in women worldwide. Over the years, breast cancer treatment has undergone revolutionary changes especially for women with hormone receptor positive metastatic disease. As a result, women are living longer with their disease, particularly in developed countries. The use of cyclin-dependent kinase (CDK) 4/6 inhibitors with antiestrogen therapy is a relatively new therapeutic option which has been shown to improve progression-free survival. Hematologic adverse events, most frequently neutropenia, are well-known side effects of CDK 4/6 inhibitors. However, to our knowledge, aplastic anemia has never been reported. We report a case of aplastic anemia in a patient with metastatic breast cancer treated with palbociclib after multiple prior lines of therapy.

Plasma Cell Leukemia Presenting as a Chest Wall Mass: A Case Report.

Plasma cell leukemia (PCL) is an uncommon neoplasm of plasma cells, with an aggressive clinical course and poor outcome, even with current standard of care. It can occur either de novo (primary PCL) or as a progression of multiple myeloma (MM). This disease has unique diagnostic criteria but certain genetic markers and clinical features may overlap with MM. Due to the low prevalence of PCL, guidelines on its management are extrapolated from the management of MM and based on small retrospective studies and cases reports/series. We present an interesting case of PCL in a middle-aged African-American male, who was diagnosed incidentally after chest wall imaging for an unrelated complaint. The diagnostic approach, management and outcomes of PCL are discussed.

Aromatase Inhibitor-Induced Erythrocytosis in a Patient Undergoing Hormonal Treatment for Breast Cancer.

Aromatase inhibitors (AIs) are most commonly used for breast cancer patients with hormone receptor positive disease. Although the side effect profile of aromatase inhibitors is well known, including common side effects like arthralgia, bone pain, arthritis, hot flashes, and more serious problems like osteoporosis, we present a case of an uncommon side effect of these medications. We report the case of a postmenopausal woman on adjuvant hormonal therapy with anastrozole after completing definitive therapy for stage IIIB estrogen receptor-positive breast cancer, who was referred to hematology service for evaluation of persistent erythrocytosis. Primary and known secondary causes of polycythemia were ruled out. On further evaluation, we found that her erythrocytosis began after initiation of anastrozole and resolved after it was discontinued. We discuss the pathophysiology of aromatase inhibitor-induced erythrocytosis and reference of similar cases reported in the literature.