Left Lower Abdominal Pain as an Initial Symptom of Multiple Myeloma

Multiple myeloma can present with various general symptoms such as fever, fatigue, and night sweats. Bone pain can occur in the pelvic and vertebral bones. However, there are a few reports of abdominal pain as an initial symptom of multiple myeloma. Here, we report the case of a 73-year-old male patient with a chief complaint of acute left lower abdominal pain. The abdominal physical findings were unremarkable. The pain was considered as referred pain, but there was no pain in response to a knock on the back. Further investigation using enhanced abdominal CT revealed a lesion in the left vertebral arch of the 10th thoracic vertebra. Bone marrow biopsy led to a diagnosis of IgA-type multiple myeloma. This case shows that abdominal pain could indicate vertebral lesions, and even without back pain, the condition of the vertebral arches should be investigated.