A 58-year-old woman with an incidental subpleural nodule found in 2020 during evaluation of exertional angina developed persistent respiratory symptoms after COVID-19 infection. PET CT demonstrated active lesions in the lungs and frontoparietal lobes. After initial diagnosis of squamous cell carcinoma (SCC) on endobronchial fine needle aspirates, a brain biopsy found perivascular and intraparenchymal inflammatory changes without evidence of malignancy. SCC was not confirmed in subsequent biopsies. Rheumatologic evaluation of diffuse arthralgias was unremarkable. Serial MRI brain revealed resolution of previously enhancing lesions after steroid treatment and new regions of parenchymal and leptomeningeal enhancement.  

Three months later, she developed left leg weakness and paresthesias. MRI revealed new contrast-enhancing cerebellar and occipital lesions, as well as a longitudinal partially ring-enhancing lesion in the thoracic spinal cord. Imaging also demonstrated  lesions in the lungs and lumbar paraspinal musculature. Spinal fluid studies showed 39 nucleated cells (lymphocyte predominant), 129 mg/dl protein, and normal glucose. Repeat lung biopsy with wedge resection confirmed grade III lymphomatoid granulomatosis. High-dose steroids provided near-resolution of symptoms. She is receiving systemically directed chemotherapy in a clinical trial with dramatic reduction in lung and CNS lesion burden.