A 59 y.o. male being treated for melanoma comes in with shortness of breath. His CT is shown below.

What is the diagnosis?


Our patient had a non infectious pneumonia(organizing pneumonia) which presents with a specific pattern called the” atoll” sign in 10% of patients on nivolumab. There is a ring of inflammation around an area of central clearing.   Nivolumab is the current treatment for melanoma. Organizing pneumonia (also called BOOP- bronchiolitis obliterans or COP-cryptogenic organizing pneumonia) is also found to  association with rheumatoid arthritis, dermatomyositis and amiodarone.  It was first described by Gary Epler in 1985.  Bronchoscopy shows up to 40% lymphocytes in the bronchoalveolar lavage.

The atoll is a coral reef around a sunken istand

The atoll is a coral reef around a sunken istand

Rather than treating these individuals with antibiotics, they are treated with steroids. Below is the CT of our patient after treatment with steroids.

niv improv with steriods.JPG

Patients on nivolumab can also have other non infectious pneumonias including NSIP, USIP and AIP. The definitions are included below (NOT required reading)

niv org pneumf.jpg

Non-specific interstitial pneumonia is a form of interstitial lung disease resulting in fibrosis.  It includes lung disease that cannot be classified into UIP, AIP, organizing pneumonia, lymphoid interstitial pneumonia or desquamative interstitial paneumonia.

UIP- usual interstitial pneumonia is characterized by progressive scarring of both lungs.  It is the most common form of interstitial fibrosis.

AIP- acute interstitial pneumonitis or Hamman-Rich appears as ARDS with diffuse alveolar damage and fluid in the alveoli.. 


Our patient has been on nivolumab intermittently with recurrence of lung disease every time he is placed on the drug. Case courtesy of Dr. Bhalla. 


Clin Cancer Res 2016 Dec 15;22(24) 6051-6060 Epub Aug1

Radswiki et al. Reversed hal sign. Radiopaedia.

Epler GR.  Bronchiolitis obliterans organiaing pneumonia. 25 years: a variety of causes, but what are the treatment options? 2011. Expert Rev Respir Med 5(3):353-61.

Li X, Pen S, Wei L. Nonspecific interstitial pneumonia overlaps organizing pneumonia in lung-dominant connective tissue disease. International Journal of Clinical and Experimental Pathology 2015;8(9);11230-11235.