# Extremely Large Fluid Collection in the Superior Aortic Recess Misdiagnosed as Mediastinal Tumors: A Report of Two Cases

## TL;DR

This paper reports two cases where fluid in the superior aortic recess was mistaken for tumors, leading to unnecessary surgery.

## Contribution

Highlights diagnostic challenges of fluid collection in the superior aortic recess mimicking mediastinal tumors.

## Key findings

- Fluid collection in the superior aortic recess can be misdiagnosed as a cystic tumor.
- Large fluid volume and cephalad extension contributed to misdiagnosis.
- Surgical resection occurred due to diagnostic uncertainty.

## Abstract

The superior aortic recess is one of the superior portions of the transverse sinus which is located around the ascending aorta. The fluid collection of the superior aortic recess is sometimes revealed on chest computed tomography, and it becomes more difficult to differentiate from a cystic tumor or lymphadenopathy when the amount of collected fluid is large or the fluid is extended into another area. We report two cases of fluid collection in the superior aortic recess which was misdiagnosed as a cystic mediastinal tumor that underwent surgical resection. An extremely large amount of fluid collection and cephalad extension led us to this clinical course.