Significance of halo, reversed halo and air crescent signs in lymphomatoid granulomatosis and pulmonary fungal infections.

We read with interest the article by Lota et al. The authors report a case of lymphomatoid granulomatosis (LG) with an atypical CT finding of crescent sign for LG. Typically, LG patients with lung involvement can present with pulmonary infiltration and may later develop a reversed halo sign, a focal round area of ground-glass attenuation and surrounding airspace consolidation of crescent shape. Although the reversed halo sign is relatively specific to a diagnosis of cryptogenic organising pneumonia, there have been reported cases of a reversed halo sign in patients with LG, sarcoidosis, pulmonary paracoccidioidomycosis and other