Thymic haemangioma presenting with a left innominate vein aneurysm: insight into the aetiology

Abstract

Thymic haemangiomas and innominate vein aneurysms are rare with only 7 and 19 previous cases, respectively, reported in the medical literature. The aetiology of an innominate vein aneurysm remains unclear and there is no previous report of tumour involvement. We present the case of a 27-year old male with concomitant mediastinal tumour and innominate vein aneurysm who underwent surgical treatment. The tumour intruded into the lower section of the innominate vein, thus causing aneurysmal dilation. Pathologically, the tumour was diagnosed as a thymic cavernous haemangioma involving the left innominate vein. This is the first case of a thymic haemangioma presenting with an innominate vein aneurysm, and suggests that tumours may be involved in the aetiology of innominate vein aneurysms.

Figure 1:

(A) Chest roentgenogram showing left mediastinal widening (arrows). (B) Plain chest CT showing an abnormal oval shadow with pheboliths (arrow). (C and D) Three-dimensional enhanced CT showing the aneurysm (*) and tumour (+). (E) Operative findings. Proximal and distal portions of the innominate vein were taped. The tumour (+) could not be separated from the aneurysm (*). (F) The remnant innominate vein was sutured (arrows).

Figure 2:

(A and B) Photographs of the left innominate vein on the left thymic tumour. (C) Photomicrograph of the tumour showing prominent ectatic vessels filled with blood. (D) The transitional portion (+) is observed between the left innominate vein (*) and the haemangioma.