Clinical Problem-Solving: Lower Extremity Weakness & Paresthesia in an Immunocompromised Patient With a Complex Cancer History

We present a case of new onset bilateral lower extremity weakness, paresthesia, urinary retention and bowel incontinence in a 51-year-old man. He had a complicated history of acute myelogenous leukemia with known central nervous system (CNS) and leptomeningeal involvement status post allogenic stem cell transplant complicated by chronic graft versus host disease (GVHD). We review the differential diagnosis as the physical exam and diagnostic results evolved. We also provide a review of the relevant literature supporting our favored diagnosis, as well as other competing diagnoses in this complicated case. The ultimate differential diagnosis included viral myelitis, treatment-related myelopathies, and CNS GVHD. The case provides a sobering reminder that even with an appropriate diagnostic workup, some cases remain refractory to therapeutic efforts. It also underscores the importance of a sensitive neurologic exam, given the significant clinico-radiological delay, and reviews the complex differential diagnosis for myelopathy.