Multiple Myeloma Presenting as a Lytic Bone Lesion

Lytic bone lesions first identified on imaging often elicit a broad differential diagnosis. This differential includes fibrous dysplasia, eosinophilic granuloma, enchondroma, giant cell tumor, non-ossifying fibroma, osteoblastoma, multiple myeloma, metastasis, aneurysmal bone cyst, solitary bone cyst, hyperparathyroidism, infection, chondroblastoma, and chondromyxoid fibroma1. Fortunately this broad differential can be narrowed based on patient demographics and specific imaging characteristics. While many of these osseous lesions are benign, it is important to consider malignant causes that warrant further work-up. In this article, we discuss an elderly patient who presents with laboratory abnormalities related to a lytic bone lesion. The diagnosis was initially suggested from a CT abdomen/pelvis finding and subsequently confirmed by bone marrow biopsy and additional laboratory testing. This case report focuses on the imaging and differential considerations in this patient population, as well as additional considerations in the evaluation and treatment of patients with multiple myeloma.