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A6952 - Cannonball Pulmonary Nodules: Necrotizing Sarcoid Granulomatosis or Mycobacterium Tuberculosis?
Author Block: A. Londono1, L. Miyakawa2, J. Filopei2; 1Internal Medicine, Mount Sinai Beth Israel, New York, NY, United States, 2Pulmonary and Critical Care Division, Mount Sinai Beth Israel, NY, NY, United States.
Introduction: The differential diagnosis for rapidly growing ‘cannon ball’ pulmonary nodules commonly includes metastatic disease of primary cancers including renal cell, germ cell or prostate carcinoma. Less common presentations includes fungal and mycobacterial infections or necrotizing sarcoid granulomatosis (NSG). We present a case of rapidly expanding pulmonary nodules with a presumed diagnosis of culture negative tuberculosis (CNT) given a response to anti-tuberculous therapy.
Description: A 36-year-old undomiciled African American male with history of intranasal heroin use presented with worsening shortness of breath, fevers, and pleurisy despite outpatient antibiotic therapy for presumed pneumonia. Physical exam revealed a well appearing male with tachycardia, decreased bibasilar breath sounds, and no testicular masses. CT Angiogram with pulmonary embolism protocol (CTPA) was performed and revealed innumerable ‘cannon ball’ pulmonary nodules. This prompted a high suspicion for occult malignancy so additional imaging including CT abdomen and pelvis were performed but results were unremarkable. PET-CT was pursued and showed highly PET avid nodules increased in size from three weeks prior. Trans-thoracic needle biopsy was performed and showed non-caseating granulomas without any organisms. Serum biomarkers for atypical infections and rheumatological disease was negative.
Given the unclear diagnosis, worsening clinical imaging, and concern for a granulomatous like reaction secondary to un-diagnosed malignancy, video assisted thoracic surgical biopsy was performed and showed necrotizing granulomas. Empiric anti-tuberculous therapy was started and patient isolated due to undomiciled status. After 3 weeks of treatment, repeat chest CT showed improvement of nodules.
Discussion:
Cannonball pulmonary nodules are often suggestive of metastatic lesions; however, NSG and CNT should be considered once malignancy has been fully excluded. CNT needs to be considered and potentially treated as the treatment of symptomatic NSG requires corticosteroid therapy, a harmful treatment if in fact the diagnosis is CNT. Based on literature review, these two diagnoses can be difficult to differentiate and require following cultures and monitoring response to anti-tuberculous therapy, particularly in endemic areas or with traditional risk factors for tuberculosis. A case series of more than 100 patients from Mayo Clinic showed that at least in 50% of cases with ‘cannon ball’ like pulmonary nodules and pathology showing necrotizing granulomatous disease, no definitive diagnosis was found despite an extensive retrospective chart review. In our case, continued surveillance of cultures and clinical course for signs of NSG as well as four months of anti-tuberculous therapy for CNT given his positive response were recommended.