Colored Lingular Segment of the Male Left Lung, Medial View

Description

Medial to the left lung, the colored lingular segment (segmentum lingulare) is presented as a tongue-like projection of the superior lobe that drapes anteroinferiorly toward the costomediastinal recess. The lingula lies anterior to the hilum and pericardial surface, with its bronchopulmonary parenchyma positioned inferior to the apicoposterior and anterior segments of the upper lobe and superior to the diaphragmatic surface. At the medial aspect, the segment relates closely to the cardiac impression created by the left ventricle, while the oblique fissure runs posteroinferiorly to separate upper-lobe tissue from the inferior lobe. Segmental boundaries are implied by the distribution of the superior lingular and inferior lingular bronchi (B4 and B5) and their accompanying pulmonary arterial branches. A medial perspective matters because lingular disease often masquerades as left lower lobe pathology on frontal chest radiographs, and bronchoscopy planning depends on knowing whether the target is B4 or B5. Atelectasis or bronchiectasis in the lingula commonly tracks along its long anteroinferior axis, and mucus plugging can present with a band-like opacity adjacent to the left heart border (the classic silhouette sign localization). Surgeons also think in segments: a lingular segmentectomy or lingulectomy relies on predictable relationships between segmental bronchi and arteries at the anterior hilum and along the intersegmental plane with the remainder of the upper lobe. Use this illustration for teaching bronchopulmonary segments in thoracic anatomy, for radiology lectures on lobar and segmental localization, or for operative planning figures in thoracic surgery texts discussing VATS lingulectomy and segmentectomy. Anatomical accuracy verified by SciePro's Medical Advisory Board.