ABSENCE OF RIGHT HORIZONTAL FISSURE AND LEFT OBLIQUE FISSURE IN A PAIR OF LUNGS A CADAVERIC CASE REPORT.

Introduction: Situated on either sides of the heart and other structures in the mediastinum, and occupying the major part of the thorax, the pair of lungs act as the essential organ of respiration. Generally right lungs is divided into three lobes by one right horizontal and one right oblique fissure while the left lung is divided into two lobes by left oblique fissure. Variation in embryological origin may cause incompleteness or absence of fissures and thus changes in lobar arrangements. Material&Method: During performing routine dissection for undergraduate students, this rare case was noticed in the lungs of a 58 years old formalin fixed female cadaver in the Department of Anatomy of Regional Institute of Medical Sciences, Imphal. The specimen was photographed and comparisons were made with normal ones. Result: The right lung showed the presence of a single fissure. The oblique fissure was present and it divided the lung into two lobes namely upper and lower lobe. However, horizontal fissure was absent. In the left lung, there was absence of the oblique fissure. Costal surface and structures passing through hilum were normal in both sides. Conclusion: The lung fissures enhance uniform expansion, and can be used as reliable landmarks in thoracic lesions. Surgically, the gradation of fissure is important for approaching the ligation of vessels and bronchi through the depth of the fissure. Knowledge of anatomical variation in fissures is important for segmental resections, lobectomies and radiological reporting of lung pathologies.