Septal Lines < RECENT >

This is a far more ominous sign. When the septal lines look like a string of pearls or appear "beaded," it suggests that nodules are sitting within the interlobular septa. The classic cause for this is lymphangitic carcinomatosis . This occurs when cancer—often from the breast, stomach, or lung—spreads through the lymphatic channels of the lung. The tumor cells obstruct the lymphatics, causing nodular expansion of the septa. This pattern can mimic edema on a cursory glance, but the nodularity and the clinical history of malignancy reveal the true nature of the disease. It can also be seen in sarcoidosis, where granulomas form along the lymphatics.

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The diagnostic value of analyzing septal lines lies in the pattern of thickening. Radiologists categorize septal thickening into three distinct morphologies, each pointing toward a different etiology. septal lines

Septal lines are thin, linear opacities seen on chest radiographs (and HRCT) that represent thickening of the —the connective tissue partitions between the secondary pulmonary lobules. They are a hallmark of interstitial lung disease , specifically indicating fluid, cellular infiltration, or fibrosis in the pulmonary interstitium. This is a far more ominous sign