200 Section - From Back Pain to Paraplegia: A Rare Case of Mast Cell Sarcoma Causing Non-Traumatic Spinal Cord Injury

Case Diagnosis: A malignant non-traumatic spinal cord injury (NSCI) secondary to metastatic mast cell sarcoma involving the thoracolumbar and sacral spine. MRI showed extensive infiltrative lesions causing significant spinal cord compression. Biopsy demonstrated CD45- and CD117-positive malignant neoplasm consistent with mast cell sarcoma. Given ascending paresthesias and neurologic deficits extending beyond the level of compression, a superimposed chronic inflammatory demyelinating polyneuropathy (CIDP) was suspected. No electrodiagnostic (EDx) study has been performed; EDx testing is recommended to confirm or exclude CIDP, as diagnostic clarification may influence prognosis and management.

Case Description: A 57-year-old man with independent baseline function developed progressive low back pain, bilateral lower-extremity weakness, and ascending sensory loss over 11 months, progressing to paraplegia with neurogenic bladder and bowel. MRI revealed multifocal thoracolumbar and sacral metastatic involvement with marked spinal cord compression. Neurosurgery deemed the lesion nonsurgical, and the patient began radiotherapy and corticosteroids. PM&R evaluation found complete motor loss below T7, severe lower-extremity atrophy, impaired sensation, and dependence in all mobility and ADLs. Rehabilitation focused on bowel and bladder retraining, progressive sitting tolerance, core activation, upper-extremity strengthening, and education on autonomic dysreflexia, DVT risk, and pressure injury prevention. Therapy started after confirmation of spinal stability.

Discussions: This case demonstrates the diagnostic complexity of malignant NSCI, particularly when symptoms may reflect both structural compression and potential inflammatory neuropathy. Early rehabilitation is crucial for preventing secondary complications, optimizing residual function, and establishing realistic goals. Suspicion of CIDP highlights the need for EDx assessment, which could significantly impact therapeutic planning and prognosis.

Conclusions:

Despite irreversible paraplegia, early coordinated rehabilitation resulted in improved trunk control, sitting balance, and upper-extremity strength. This case emphasizes the value of early PM&R involvement in malignant NSCI and the need for EDx testing to clarify the contribution of possible CIDP. Interdisciplinary management remains essential for optimizing outcomes and quality of life.