Background: Knowledge of anatomical variations is required for the proper diagnostic and surgical purposes. Variations in the number of lobes, fissures and pattern of division of lobes are common in lungs. In some cases fissures may be incomplete or absent. This article is a case report of unusual lobe in the right lung. The accessory lobe was named as Wrisberg’s lobe, who describes the lobe firstly. Stoloff in 1929 published a report of 5 cases. The shadow found in chest X – rays in early ages raises the question of extra lobe. Although the azygos lobe is a rare anomaly its radiological appearance has been well defined. Presence of extra lobe of lung would not be always detectable in radiological appearance. An azygos lobe may be confused with a pathological air space such as a bulla or abscess [1,2]. In addition, the abnormally located azygos vein may be mistaken for a pulmonary nodule, while a consolidated azygos lobe may be confused with a mass. The detection of this anomaly and its interpretation of its anatomical features are interesting not only to anatomists but also helpful to pathologists and surgeons. The size and shape of the lobe varies considerably. This study aims to review some literatures about the accessory lobe and the clinical conditions which may cause. Present variation was found in a routine dissection in the department of anatomy. The anomalous lung was removed and studied. The embryological and clinical aspect of the case was discussed. Variations of lung anatomy are important for both the diagnosis and treatment of various diseases involving all the domains of medicine. The lobe, may however, be the seat of pathology localized in the lobe itself and subject to the same influences as other purely lobar conditions. The azygos fissure may be the site of pleurisy or exudates.

Key words: Azygos Lobe; Azygos Fissure; Right Lung.