A Case of Second Primary Multiple Myeloma Mimicking Bone Metastases in a Patient with Breast Cancer: An Approach to Osseous Metastases

Abstract

A 62-year-old female patient received adjuvant chemotherapy after a mastectomy due to a locally advanced invasive ductal carcinoma eight years ago. During the follow-up, she complained of extensive backache, so a plain radiography was taken. The radiography showed diffuse lytic lesions located primarily around the vertebrae and sternum. Given that the bone lesions could be related to osseous metastases of the breast cancer, a bone scintigraphy was performed and no positive involvement was observed. Magnetic resonance imaging was subsequently applied and diffuse hypointense areas were found on the vertebrae. The patient had also accompanying bicytopenia (thrombocytopenia and luecocytopenia), albumin/globulin inversion and hyperglobulinemia. As the patient did not have such involvement in regard to her overall body scintigraphy and there were accompanying abnormal biochemical parameters, it was concluded that the patient’s bone lesions were an outcome of a hematological malignity. Bone marrow aspiration and the biopsy result were found to be consistent with multiple myeloma (MM). It was thus confirmed that the lytic lesions were not related to breast cancer but rather MM bone lesions. We are able to conclude, based on the case presented herein, that newly-developing bone lesions on patients with breast cancer must be approached with suspicion, and their other laboratory analyses and imaging diagnostic processes must be evaluated carefully. It is necessary to keep in mind that such a condition might be related to other diseases, however rare the occurrence.