Repeat CSF flow cytometry and cytology were concerning for lymphoma. While initial scans and serum studies were negative for malignancy, PET found a right adrenal mass that, on biopsy, unveiled a diffuse large B-cell lymphoma. Repeat MRI of the brain and spine revealed multiple enhancing lesions along multiple nerve roots, the hypothalamus, globus pallidus and corpus callosum. Ultimately, he began systemic and intrathecal chemotherapy with subsequent improvement in exam.

This patient's complex presentation with upper and lower motor neuron signs, and multiple cranial neuropathies, made for a challenging diagnosis. While cervical stenosis, motor neuron disease, and immune-mediated neuropathy were entertained as diagnoses, ultimately a treatable cancer was discovered. This reinforces the importance of avoiding anchoring bias when an evolving clinical picture does not fit prior diagnoses.