An unusual case of persistent consolidation: Idiopathic lymphoid interstitial pneumonia

Abstract Lymphocytic interstitial pneumonia (LIP) is a rare but largely benign interstitial lung disease, most frequently associated with HIV and autoimmune conditions. It is infrequently found to be an idiopathic condition. Diagnosis is complex and can require numerous invasive tests as evidenced in the case presented. The diagnosis is made from a combination of clinical, radiological, and histological features but the unusual radiological and clinical features meant diagnosis in our case required surgical biopsy. There is minimal evidence around best treatment although largely involves targeting the underlying cause. There is a small risk of transformation to lymphoma and fibrosis. Immunosuppression with steroids is the most common therapeutic strategy however in our case the radiographic changes spontaneously resolved. We present a case of an immunocompetent male presenting with significant radiological and histopathological findings of LIP, without significant symptomatology, that spontaneously resolved without intervention suggesting a monitoring approach may be a valid management strategy.