Metastatic Breast Cancer with Extensive Osseous Metastasis Presenting with Symptomatic Immune Thrombocytopenic Purpura and Anemia: A Case Report and Review of the Literature

BACKGROUND: Immune thrombocytopenic purpura (ITP) is a rare acquired bleeding disorder with an estimated incidence of 1 in 10,000 people in the general population. The association of ITP with breast cancer is an even rarer entity with very limited reports in the English literature. CASE PRESENTATION: We report a case of a 51-year-old female with no significant past medical history who presented with sudden onset of malaise, syncope, gingival bleed and epistaxis. She was found to have severe thrombocytopenia (platelet count 6,000/μl) and anemia (hemoglobin 7.2 g/dl). Her workup led to the diagnosis of metastatic ductal breast cancer with extensive bone metastasis. Bone marrow biopsy demonstrated myelophthisis which was initially thought to be consistent with her presentation of thrombocytopenia and anemia. Therefore, the patient was started on hormonal therapy for the treatment of her metastatic breast cancer. After 3 months of therapy, she did not improve and developed severe mucosal bleeding. Her clinical presentation was suspicious for ITP and immune-mediated anemia, and hence she was started on steroids and intravenous immunoglobulin. The patient had a dramatic response to therapy with normalization of her platelet count and hemoglobin within 2 weeks. CONCLUSION: To our knowledge, this is the first reported case of metastatic breast cancer presenting with symptomatic ITP and anemia, and both symptoms are postulated to be immune-mediated.