The Nodules Before the Headache

A 58-year-old woman with end-stage kidney disease secondary to hypertensive nephrosclerosis underwent deceased-donor kidney transplantation six months ago. Her baseline immunosuppression includes tacrolimus 3 mg twice daily (trough 6.2 ng/mL at last check), mycophenolate mofetil 1000 mg twice daily, and prednisone 5 mg daily. Six weeks ago, a surveillance biopsy showed Banff grade IB acute cellular rejection, treated with three days of intravenous methylprednisolone 500 mg daily. Her creatinine improved from 2.1 to 1.5 mg/dL and she was discharged on her prior oral regimen.

Twelve days ago she developed right-sided pleuritic chest pain, a dry cough, and low-grade fevers to 38.2 C. She attributed the symptoms to a viral illness and did not seek care. Over the next week the fevers continued, fatigue worsened, and she noticed mild dyspnea climbing stairs. Two days ago she developed a new frontal headache that woke her from sleep, accompanied by difficulty concentrating and word-finding pauses during conversation. Her husband noted she seemed confused about the date.

In the emergency department her temperature is 38.6 C, heart rate 96/min, blood pressure 142/88 mmHg, respiratory rate 20/min, and oxygen saturation 94% on room air. She is alert but mildly disoriented to time. There are fine crackles at the right base. No focal motor deficits are present, but she pauses mid-sentence and occasionally substitutes incorrect words. Neck is supple. There is no skin rash.

Laboratory studies show white blood cells 11.4 x 10^3/uL with 78% neutrophils, hemoglobin 10.8 g/dL, platelets 198 x 10^3/uL, creatinine 1.7 mg/dL (up from 1.5 mg/dL baseline), and C-reactive protein 12.4 mg/dL. Tacrolimus trough is 8.4 ng/mL (elevated from her usual 6 to 7). Serum galactomannan returns at 0.3 optical density index (negative cutoff less than 0.5). 1,3-beta-D-glucan is pending. Blood cultures show no growth at 48 hours.

Chest CT reveals multiple bilateral peripheral nodules ranging from 0.8 to 2.4 cm, at least two of which are cavitary with thin walls, surrounded by rimming ground-glass attenuation. There is no pleural effusion or mediastinal adenopathy. Brain MRI with contrast demonstrates a 1.8-cm ring-enhancing lesion in the right frontal white matter with surrounding vasogenic edema and a second 1.1-cm enhancing lesion in the left cerebellar hemisphere.