Computed Tomographic Appearance of Organizing Pneumonia in an Oncologic Patient Population

The aims of this study were to describe the computed tomographic features of organizing pneumonia (OP) in an oncologic patient population and to also identify features associated with lung cancer and patients undergoing hematopoietic stem cell transplant (HSCT).

In retrospective computed tomographies from 151 patients with pathologically confirmed OP between January 2009 and September 2014, number of lesions, location, size, margin type, and consistency, as well as volume of lymphadenopathy and the presence and size of pleural effusions, were recorded. Associated malignancy was noted.

Organizing pneumonia most commonly presented as a diffuse process (n = 62, 41%), frequently occupied both a central and peripheral location (n = 79, 53%), and commonly presented with a solid appearance (n = 67, 44%) or with ground glass opacity (n = 80, 53%). Pleural effusions were seen in 68 patients (45%). Organizing pneumonia less frequently contained air bronchograms, cavitation, necrosis, surrounding ground glass opacity, or adjacent bronchiectasis. In patients with lung cancer (n = 25, 17%), OP more likely presented as discrete lesions and occupied a peripheral location as compared with patients with other malignancies (Ps = 0.025 and 0.002). In HSCT patients (n = 29, 19%), a diffuse process was more commonly seen than in non-HSCT patients (P = 0.038).

Organizing pneumonia more commonly presents as discrete lesions with a peripheral location in patients with lung cancer and as a diffuse process in patients who had undergone HSCT.