Intrathecal Methotrexate-Induced Necrotizing Myelopathy: A Case Report and Review of Histologic Features

Area of Science:

• Neurology
• Oncology
• Pathology

Background:

• Central nervous system (CNS) relapse of acute lymphoblastic leukemia (ALL) carries a poor prognosis.
• Intrathecal (IT) methotrexate is used prophylactically to reduce CNS relapse but can cause neurologic complications.
• Transverse myelopathy, a form of isolated spinal cord dysfunction, is a known complication of IT methotrexate.

Purpose of the Study:

• To describe the rare histologic features of transverse myelopathy following prophylactic IT methotrexate administration.
• To document the autopsy findings in a patient with T-cell ALL who received IT methotrexate.

Main Methods:

• Autopsy examination of a 31-year-old male patient with a history of T-cell ALL.
• Microscopic analysis of spinal cord tissue.

Main Results:

• Transverse necrosis of the thoracic spinal cord with significant macrophage and lymphocyte infiltration.
• Cavitary necrosis in cervical and lumbar spinal cord, affecting gray and white matter.
• Extensive subpial vacuolar degeneration in dorsal and lateral columns.

Conclusions:

• IT methotrexate, while effective in preventing CNS relapse in ALL, can lead to severe myelopathy.
• The autopsy findings illustrate the extensive neuropathologic changes associated with IT methotrexate-induced transverse myelopathy.
• Detailed histologic descriptions are crucial for understanding and potentially mitigating this serious complication.