70 yo M with confusion and a lung nodule


  • Broad evaluation of altered mental status (optional, ~10 min)
  • Recognize the sensitivity/specificity of CT guided biopsy in the evaluation of lung nodules


70 yo M with no known PMH who was brought in for 5 weeks of progressive malaise, anorexia and confusion. He was seen at urgent care 2 weeks ago for a nonproductive cough that has been ongoing for ~ a month and was treated with oseltamivir without improvement in symptoms. He has been slightly disoriented over the past few weeks but was significant worse over the past 2 days and was found at home to be incomprehensibe on the day of presentation. He otherwise has not seen a health care provider in decades and has no known PMH and takes no medications. He does not drink, smoke, or use illicits.

On exam, he is afebrile, VS are notable for HR in the 100-110s, RR 20s, BPs 130/70s, saturating in the mid 90s% on RA. He is thin, in no distress. He is oriented to self only and makes nonsensical statements when asked questions but otherwise has no motor deficits. Cardiopulmonary exam is unremarkable except for tachycardia.

His initial labs are notable for Na 129, K 3.8, Cl 98, HCO3 21, Cr 3.1 (no baseline), WBC elevated at 20.99 (PMN predominant), hct 38, plts 315.

What additional work-up would you want for this patient? (~10 min)  


How does this change your differential? Do you want any additional work-up?

What other diseases are associated with this pathology? (~3-5 min)


What is it?

How is it diagnosed?

All of his initial evaluation and presentation seemed to point towards malignancy.

How good is a negative CT-guided core biopsy for excluding malignancy?



  1. Lutalo, P & Cruz, D. “Diagnosis and classification of granulomatosis with polyangiitis (aka Wegener’s granulomatosis)” 2014. Journal of Autoimmunity. 48-49: 94-99.
  2. Quint, et al. “CT guided thoracic core biopsies: value of a negative result?” 2006. Cancer Imaging. 6(1): 163 – 167
  3. Mahr, A, et al. “ANCA-associated vasculitis and malignancy: Current evidence for cause and consequential relationships.” 2013. Best Practice and Research Clinical Rheumatology. 27(1): 45-56.
  4. Mukhopadhyay, et al. “Pulmonary necrotizing granulomas of unknown cause: clinical and pathologic analysis of 131 patients with completely resected nodules.” 2013. CHEST. 144(3): 813-24.