An Unusual Presentation of Multiple Myeloma: A 71-Year-Old Female With a Single Lytic Lesion of Her Appendicular Skeleton.

Multiple myeloma is a devastating illness with a hallmark of end-organ damage. The clinical presentation of multiple myeloma often includes the involvement of CRAB (hypercalcemia, renal failure, anemia, bone lesions) symptoms. We present a case of a patient who did not exhibit the typical presentation of multiple myeloma making her case unique and her diagnosis more difficult. In addition to the CRAB criteria, typical symptomatology includes constipation, pain, fatigue, and peripheral sensory issues. The purpose of this case report is to bring awareness to both multiple myeloma and this particular presentation. The patient is a 71-year-old female with a past medical history of hypertension, hypothyroidism, and rheumatoid arthritis who presented with a chief complaint of right shoulder pain. The patient's initial labs were significant for a total protein of 9.3, albumin of 3.4, corrected calcium of 9.3, hemoglobin 10.6 (with baseline near 11-12), and creatinine of 1.0 (baseline of 1.0). The patient's right upper extremity X-rays were significant for a right humeral fracture. The patient had a serum kappa/lambda ratio of 15.94. Bone marrow biopsy revealed 50% kappa-restricted cells, consistent with a diagnosis of multiple myeloma. The patient's subsequent bone survey and CT scan were negative for any additional lesions. The patient had subsequent radiation therapy followed by maintenance therapy with bortezomib, lenalidomide, and dexamethasone with improvement in her symptoms. MM is a complex pathophysiological disease and equally as complex in diagnosis as the presentation is varied and sometimes obscure as noted in the case presented here. Although bone lytic lesions are part of the CRAB criteria, it is rare for them to present in patients with MM in an isolated manner with no corresponding lab abnormalities. With this case, we aim to shed light upon an atypical presentation of MM, notably one that solely involves a pathological fracture in a non-axial distribution.