1528 - Median and Ulnar Neuropathies in a Patient with Multiple Myeloma after a Pathologic Humerus Fracture

Thursday, February 19, 2026

5:00 PM - 6:30 PM AST

Presenting Author(s)

re

ravahn enayati, MD

Resident
New York Presbyterian-Cornell-Columbia
New York, New York, United States

Co-Author(s)

JP

Jesuel Padro Guzman, MD

Cancer Rehabilitation Physiatrist
Memorial Sloan Kettering Cancer Center
New York, New York, United States

Submitter(s)

re

ravahn enayati, MD

New York Presbyterian-Cornell-Columbia
New York, New York, United States

Case Diagnosis: A 66-year-old man with relapsed multiple myeloma presented with lytic bone lesions and a complicated inpatient course due to a fall, resulted in a pathologic fracture of the left humeral neck and subsequent numbness and pain along the left arm. Electromyography (EMG) revealed median and ulnar neuropathies localized to the left forearm. Multimodal imaging ruled out malignant nerve or plexus infiltration and cervical radiculopathy, suggesting congestion as the cause of these neuropathic symptoms.

Case Description: The patient initially arrived with acute back pain following a fall, which revealed extensive spinal lesions due to myeloma with cord compression. Soon after, he sustained a pathologic fracture of the left humerus. After surgical fixation, he developed numbness, tingling, and weakness primarily affecting the ulnar distribution and areas supplied by the median nerve. Neurologic examination indicated asymmetric distal weakness and sensory deficits consistent with median and ulnar nerve involvement. Nerve conduction studies confirmed compressive neuropathies, with stable findings over time. CT of the left arm showed subcutaneous infiltration and edema on the dorsal aspect of the elbow, skin thickening suggestive of cellulitis or lymphedema, edema surrounding the expected location of the ulnar nerve at the cubital tunnel. An extensive neuroradiology review excluded malignant or radicular causes.

Discussions: Neurologic deficits in multiple myeloma can arise from various factors. Differential diagnosis was initially broad including cervical radiculopathy, plexopathy, and direct nerve infiltration. However, detailed neuroimaging ruled out malignant causes and EMG findings localized the pathology to the distal forearm and wrist. Ultimately, the patient's neuropathies were attributed to local compressive effects from post-traumatic swelling and lymphedema rather than malignant infiltration. Supportive care, including lymphedema therapy and targeted treatments, was initiated.

Conclusions: This case underscores the importance of thorough multimodal assessment in cancer patients presenting with new neurologic symptoms. Differentiating compressive neuropathies from malignant causes is crucial to avoid unnecessary treatments.