Pulmonary actinomycosis is a rare chronic pulmonary infection caused by actinomyces, a Gram–positive, microaerophilic bacterium. Pulmonary involvement other than cervicofacial or abdominopelvic actinomycosis is uncommon and often leads to a misdiagnosis of pulmonary tuberculosis or lung cancer.

Chiari Type I malformation (CM-I) is a rare disorder with displaced cerebellar tonsils through foramen magnum. Here we present a 30-year-old man with severe central and obstructive sleep apneas as presenting manifestations of CM-I.

Carcinoid tumors comprise an uncommon group of pulmonary neoplasms with neuroendocrine origin. In comparison with typical carcinoid tumors, atypical tumors are less common and more aggressive. We present a 35-year old female with atypical carcinoid tumor.

Unilateral pulmonary artery agenesis (UPAA) is an uncommon congenital anomaly and most patients present in neonatal period with respiratory symptoms. Left-sided pulmonary artery agenesis is less frequent than right-sided and is sometimes associated with cardiac anomalies.

Tuberculous or tubercular liver abscess (TLA) is a rare manifestation of extrapulmonary tuberculosis (TB) and it should be considered in the differential diagnosis of mass or cystic lesions of the liver especially in a high TB prevalence country like Iran.