A 70-year-old woman with atrial fibrillation, liver cirrhosis, Type 2 diabetes mellitus, hypertension, and venous thrombus treated with enoxaparin presented with a 5-day history of weakness in the left arm, numbness in the left fourth and fifth digits and medial palmar surface, and confusion. The patient also reported chronic vision loss in the right eye and denied headache or recent trauma.
On initial examination, the patient was alert; oriented to person, place, and time; and disoriented to situation. Cranial nerve testing revealed reduced visual acuity in the right eye. Motor strength testing revealed 4/5 strength in the left triceps, left wrist flexors and extensors, and left finger flexors and 3/5 strength in the left finger extensors. Reflex testing revealed an absent left triceps reflex. Sensation testing revealed decreased sensation to pinprick and light touch in the fourth and fifth digits of the left hand. There was no dysmetria or dysdiadokokinesia. Head computed tomography (CT) without contrast demonstrated a 1 cm hyperdense round lesion in the suprasellar cistern [Figure 1].
The patient's limb weakness and numbness localized to either the C7/8 nerve roots or the middle and lower trunks of the brachial plexus. Our differential diagnosis included a lateralized mass in the extradural or intradural extramedullary spinal canal or idiopathic brachial neuritis. While the patient had several risk factors for embolic stroke, including atrial fibrillation and diabetes, the specific patterns of sensory loss in the left upper extremity and loss of the left triceps reflex were more suggestive of either nerve root or brachial plexus pathology. On hospital day 2, the patient developed a pupil-sparing right CN III palsy. The next day, the right pupil became dilated to 4 mm and nonreactive to light.
The new cranial nerve palsy combined with the previously seen lesion on head CT without contrast broadened the differential diagnosis to include neoplastic, infectious, and inflammatory etiologies, especially those with a predilection for invading the subarachnoid space. Considerations included leptomeningeal disease from metastatic carcinoma or lymphoma as well as PCNSL due to the patient's age and multifocal nature of her symptoms, as well as tuberculosis, histoplasmosis, coccidioidomycosis, or cryptococcosis, and sarcoidosis. The patient then underwent gadolinium-enhanced brachial plexus, brain, and spine MRI in addition to lumbar punctures and several blood tests.
The patient's Vitamin B12, Vitamin B6, folate, and lead levels were within normal limits. RPR was nonreactive and HIV-1 was negative. Hemoglobin A1c was mildly elevated to 6.7%. The ophthalmology service performed a slit-lamp examination, which showed only rare drusen. Gadolinium-enhanced brachial plexus and spine MRI were unrevealing. Gadolinium-enhanced brain MRI demonstrated enhancing lesions with heterogeneous signal intensity in the suprasellar, pineal, and right periatrial regions concerning for a lymphoproliferative, infectious, or inflammatory process and no evidence of ischemic stroke [Figure 2]. One week later, repeat gadolinium-enhanced brain MRI demonstrated an increase in the size of all enhancing lesions [Figure 3] in addition to focal right frontoparietal dural thickening. Chest/ abdomen/pelvis CT with contrast demonstrated multiple nodules in the thyroid concerning for metastases. CSF studies from two serial lumbar punctures, with respective volumes of 28 mL and 6.5 mL, demonstrated lymphocytic pleocytosis, elevated protein, and elevated IgG index but neither malignant cells nor other inflammatory and infectious markers. The neurosurgery service performed a stereotactic biopsy of the lesion in the right periatrial region, which established the diagnosis of diffuse large B-cell lymphoma.
The patient was treated with whole-brain radiation (30 Gy in 10 fractions) rather than high-dose methotrexate due to the patient's decompensated liver cirrhosis. The patient had difficulty tolerating radiation due to severe, intractable nausea, and vomiting. Postradiation head CT without contrast demonstrated reduction in the size of the intracranial lesions [Figure 4]. Her mental status did not significantly improve, and the patient was ultimately discharged home with family and palliative care.