Axillary Segment of the Right Upper Lobe

In some patients, an extra bronchus (the axillary bronchus) supplies the lateral aspect of the right upper lobe. The axillary bronchus may be subsegmental (most common) or segmental. A segmental axillary bronchus most commonly arises adjacent to the posterior bronchus.

Aspirtation in the right lateral decubitus position can preferentially involve the axillary segment.

An axillary segment can also be present on the left.

References

• Ribaudo CA, Grace WJ. Pulmonary aspiration. Am J Med. 1971 Apr;50(4):510-20.
• Slowinski J, Bloom S, Oates E. The diseased axillary segment of the lung: characteristic radiographic and scintigraphic appearance. AJR Am J Roentgenol. 1992 Oct;159(4):899-900.
• Wu JW, White CS, Meyer CA, Haramati LB, Mason AC. Variant bronchial anatomy: CT appearance and classification. AJR Am J Roentgenol. 1999 Mar;172(3):741-4.