Introduction
The transverse sinus (TS) is open at both ends and formed by the reflection of the visceral serosal pericardium from the posterior aspects of the aortic and pulmonary trunks over to the anterior aspect of the atrium (1). Thus, a finger in the transverse sinus will pass behind the aortic and pulmonary trunks but in front of the superior vena cava on the right and the left atrial appendage on the left (2). A Transesophageal Echocardiography (TEE) in the mid esophageal view can, in most cases, distinguish the location of a TS mass, without the need for further investigation (CT or MRI).
Case report: A 50-year-old diabetic woman presented with left sided numbness. The patient was admitted in Neurology for further investigation related to stroke of TIA. The clinical examination revealed that the patient was hemodynamically stable, with no motor weakness. The cardiac examination revealed a wide fixed second heart sound, and an ejection systolic murmur on the upper left sternum 2/6. The carotid was normal. The ECG was in sinus rhythm with Right Bundle Bransh Block. The laboratory report indicated a normal CBC and renal function. The HgbA1c was 7.5 with the LDL 4 mmol/L.
The TTE indicated a normal LV systolic function, normal valve, and LAVI 43 ml/m2. The right side of heart was dilated with the pulmonary artery pressure, with Resting PASP, 45 mm/hg. The TEE was done as a work up for stroke and revealed a mobile mass in the transverse sinus (TS). The differential diagnosis was a LAA thrombus (Figure 1A/b & 2A/b) or PV mass (Figure 3) versus fat in the TS (Figure 3). However, the different mid-esophageal views assisted in the distinction of the exact location of the mass, avoiding the initiation of unnecessary interventions (figure 4).