E2646. Multiple Pulmonary Nodules: Findings Suggesting Diagnosis
  1. Ramya Gaddikeri; Rush University Medical Center
  2. Maham Jehangir; Rush University Medical Center
  3. Palmi Shah; Rush University Medical Center
Multiple lung nodules are frequently encountered on CT scans. While the distribution of the lung nodules helps narrow the differential diagnosis, additional findings on CT may indicate the diagnosis. This presentation uses a case-based approach to highlight some of these less-common etiologies of multiple pulmonary nodules and associated ancillary findings that suggest the diagnosis.

Educational Goals / Teaching Points
List the less common etiologies of multiple pulmonary nodules. Describe associated CT findings for each case that would suggest the diagnosis. Briefly discuss the clinical conditions, pathophysiological characteristics, diagnosis, and follow-up where relevant.

Key Anatomic/Physiologic Issues and Imaging Findings/Techniques
Multiple lung nodules are most often secondary to metastatic disease, sarcoidosis, or infections. The less frequent etiologies of multiple lung nodules are often associated with ancillary CT findings, which, if recognized, may help the radiologist arrive at a diagnosis. Case examples will highlight Diffuse idiopathic neuroendocrine cell hyperplasia (DIPNECH). Persistent solid nodules with air-trapping. Amyloidosis, solid medium-sized nodules with popcorn calcification associated with lung cysts and ground glass opacities as seen in LIP ( Lymphocytic interstitial pneumonia). Metastatic calcification, persistent ground glass centrilobular nodules with or without calcification with vessel calcifications in the chest wall, renal osteodystrophy changes in chronic renal failure. Pulmonary meningothelial-like nodules, multiple small non-solid nodules, some showing central lucency. Histoplasmosis, multiple lung nodules with adrenal masses. M. Tb infection, multiple military nodules with discitis and osteomyelitis. Multifocal micronodular pneumocyte hyperplasia, multiple small solid nodules and scattered lung cysts in Tuberous sclerosis. Dendritic pulmonary ossification, multiple tiny calcified lung nodules and changes of interstitial lung disease. Lemierre's syndrome, multiple cavitary nodules and Internal jugular vein thrombosis. Rheumatoid nodules, multiple solid and cavitary nodules may be associated with changes of usual interstitial pneumonia. Pulmonary artery hypertension, centrilobular ground glass nodules (plexiform arteriopathy), enlarged main pulmonary artery with right heart enlargement.

Multiple lung nodules with the associated CT findings may indicate a definitive diagnosis in many less common entities. Knowledge of this helps avoid biopsy, can guide a noninvasive method for diagnosis, and suggests appropriate follow up where needed.