Large thymus tumor with invasion into superior vena cava: Transesophageal echocardiography proved to be helpful during surgery.

The Editor,

A 24-year-old male was referred with provisional diagnosis of anterior mediastinal mass with 14 weeks’ history of exertional breathlessness, facial, and right upper limb swelling. Computed tomography (CT) thorax showed encasing mass compressing the jugular vein, innominate vein along with superior vena cava (SVC), and right atrium (RA) [Figure 1]. Since our patient did not show any signs of metastasis and was symptomatic due to compression caused by SVC, urgent surgical resection with excisional biopsy was planned after taking his consent. After induction of anesthesia, transesophageal echocardiography (TEE) probe was inserted and echocardiographic examination of heart including SVC and aorta was carried out. It defined the clear margin of plane of the tumor mass from the anterior surface of heart along its right side till apex and also revealed that it hAas actually invaded the SVC and grown in and projected few millimeters into RA [Figure 2]. Color flow Doppler registered flow around this mass too [Figure 3]. On surgical approach through median sternotomy, it was found a large, hard, and pale tumor arising from the thymus compressing the right side of the heart. Further surgery into major vessels was performed after establishing full cardiopulmonary bypass by cannulating the aorta and inferior vena cava for venous cannulation and under total deep hypothermic circulatory arrest at the temperature 20°C. This en bloc tumor was sent for frozen section histopathology report that revealed it to be an invasive thymic carcinoma. Native lost SVC was reconstructed with bovine pericardium (SJM Biocor™ Pericardial Patch, St. Jude Medical Inc., Minnesota USA) [Figure 4]. The patient tolerated the surgery well, except had his symptoms reduced remarkably though had contracted elevated right dome of the diaphragm due to injury to the right phrenic nerve during dissection. After recovery, the patient underwent five cycles of radiotherapy, but unfortunately, he died after 6 months due to distant metastasis in brain.

Figure 1

Computed tomography thorax showing mass compressing over the right side of the heart encasing over the superior vena cava

Figure 2

Bicaval view (right rotated) shows tumor mass inside superior vena cava and extend of the tumor mass between the right atrium cavity and pericardium which is anterior to right atrium compressing it

Figure 3

White arrow shows flow seen around the tumor mass inside the right atrium which is also seen invaginating into the superior vena cava

Figure 4

Black arrow shows the new superior vena cava with bovine pericardium

Although surgical resection is the treatment of choice for most neoplasms in the mediastinum with the incidence of 33.9% among all thymic malignant neoplasms,[12] this surgery itself increases morbidity and mortality,[2] but tumor resection, staging, grading, or postoperative radiotherapy also influence the outcome.[134] Few reports suggest that it is difficult to decide which kind of patients would get benefit from this surgery, due to their invasive tumor nature. Our patient had remarkably improved quality of life after surgery and could tolerate the cycles of radiotherapy. Redford et al. also rightly pointed out that if compression of right-sided heart structures and invasion in the major vein like SVC (as in this case) can be properly marked by intraoperative technique like TEE then even that does not add to postoperative morbidity or mortality even after undergoing great vessels’ resection and reconstruction.[5] However, in our patient too, detailed intraoperative TEE examination helped in delineating the plane of dissection and the extent of the tumor invasion into SVC and RA facilitating tumor resection which was not detected by the CT thorax except that this tumor mass had completely encased the SVC compressing the right-sided heart anteriorly. Here, the guidance of TEE helped us over the CT thorax for better surgical planning and management. Limited data are available regarding specific modes of treatment due to its rarity and limited number of such cases.

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Conflicts of interest

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