Pulmonary sarcoidosis: from clinical features to pathology-narrative review

Sarcoidosis is a multisystem disease with unknown causes. The prevalence of sarcoidosis that occurs worldwide is highly variable. It is pathologically characterized by the formation of non-necrotizing epithelioid cell granuloma, mainly affecting the respiratory tract and involving extrapulmonary organs including the skin, heart, extrathoracic lymph nodes, central nerves and eyes. A correct diagnosis of sarcoidosis depends on the clinical symptoms, imaging observations, and characteristic histopathological findings. This study aims to review the recent contributions of pulmonary sarcoidosis. It is based on a search of a published article and review on pulmonary sarcoidosis. PubMed, Embase and CNKI were searched for latest developments from 1977. The most common clinical symptoms of sarcoidosis include dry cough, dyspnea, and chest discomfort. The imaging manifestations of sarcoidosis can be divided into typical and atypical findings. Lymphadenopathy is a typical imaging manifestation of sarcoidosis. Sarcoidosis is also a highly variable multisystem disease with an unpredictable clinical course. Clinically encountered cases cover a wide range from asymptomatic patients with incidental findings in radiographic images to chronic progressive diseases. Corticosteroids are the most widely recommended as the first-line treatment for symptomatic or organ-threatening disease in sarcoidosis, but they are associated with substantial toxic effects. Meanwhile, for sarcoidosis, the follow-up is also an important part of the diagnosis and treatment. Pulmonary sarcoidosis needs further recognition. In this paper, the clinical features, imaging observations, pathology, and treatment modalities for pulmonary sarcoidosis are presented and discussed vis-a-vis the current dilemma in diagnosis and therapy.