Rapid Progression of Metastatic Pan-spinal Epidural Non-Small Cell Lung Cancer Following Discontinuation of Alectinib.

BACKGROUND

Rapid progression of metastatic non-small cell lung cancer (NSCLC) following discontinuation of tyrosine kinase inhibitors (TKI) or anaplastic lymphoma kinase (ALK) inhibitors has been described and is associated with a poor prognosis. We describe the first reported case of accelerated NSCLC tumor extension throughout the entire spinal epidural space.

METHODS

A 68-year-old woman with stage IV ALK-positive metastatic NSCLC presented with acute neck pain, urinary retention, and lower extremity weakness 15 days following discontinuation of alectinib. MRI with contrast was significant for new compressive lesion spanning the entire cervical, thoracic, and lumbar spine which was new compared to MRI obtained 20 days prior and was suspicious for infection. Cervical (C3-C7), thoracic (T9-T12), and lumbar (L3-L5) decompression were performed with collection of culture and pathology specimens. Repeat MRI obtained for acute neurologic deterioration on postoperative day 2 noted further progression of disease and continued thoracic cord compression. Following urgent T1-9 laminectomy, specimens were again sent for pathology, cultures, and cytology. No evidence of infection was noted, and all pathologic specimens evaluated were consistent with metastatic adenocarcinoma. Despite operative intervention, the patient continued to decline, suffering from recurrent pleural effusions, and eventual cardiopulmonary arrest 11 days following admission.

CONCLUSIONS

The differential diagnosis when evaluating presumed spine epidural abscess should include tumor and metastatic disease, even in cases of rapid development. Recent termination of TKI or ALK inhibitors may result in severe disease flares, and a history of such should raise clinical suspicion for metastatic progression. In addition to cultures, biopsy for pathologic diagnosis should be collected during decompressive surgery.