Presentation
Shortness of breath. Rule out PE.
Patient Data
Air space opacity most confluent within the lingula portion of the left upper lobe in the setting of accessory left horizontal fissure. One might even be tempted to use the term "left middle lobe pneumonia". Patchy air space opacity in the bilateral lower lobes is also present. Appearance is in keeping with bronchopneumonia. No evidence of pulmonary embolus.
Patchy left lower zone air space opacity is seen. The accessory left horizontal fissure noted on CT is not well seen on the frontal chest x-ray.
Case Discussion
Accessory left horizontal fissure is relatively uncommon anatomical variant where the left upper lobe lingula is separated from the remaining left upper lobe segments by a variably sized (often incomplete) fissure. In this case there is infective consolidation within the lingula giving the impression of a "left middle lobe pneumonia".