A 19 years old male presented with a rapidly progressing painless neck swelling of 3 months duration. There were no complaints of fever or weight loss or symptoms suggestive of compression of adjacent structures. The patient was afebrile and had a cystic, non-tender, non-translucent and smooth swelling occupying the whole of the neck anteriorly, extending from the hyoid bone to the suprasternal notch. The lower limit of the swelling could not be reached. There were no neck nodes or dilated tortuous neck or chest wall veins.
Chest X-ray revealed widening of the mediastinum and a soft tissue neck swelling, continuous with the mediastinal shadow (Fig ). On neck ultrasonography, a predominantly cystic, multiseptate mass lying superficial to the thyroid lobes was evident. Fine needle aspirate cytology from the swelling showed largely necrotic material with few macrophages and mixed inflammatory cells on a background of proteinacious material, suggesting a diagnosis of a dermoid cyst. There were no acid-fast bacilli, bacterial and fungal elements on microscopy and culture. 99mTc-thyroid scan ruled out a thyroid lesion. Contrast enhanced CT of neck and mediastinum (Fig and ) showed a multi-septate, predominantly cystic neck mass, superficial to thyroid and strap muscles. The mass was continuous with a more solid intrathoracic mass with areas of calcification and cystic necrosis, extending up to the level of right atrium. The trachea was shifted to the right but there was no compression or infiltration of great vessels or mediastinal structures. There were no mediastinal lymph nodes and pulmonary lesions. A diagnosis of anterior mediastinal teratoma with cervical extension was made.
Chest x-ray (P-A view) showing widening of the mediastinum and a soft tissue swelling in the neck, continuous with the mediastinal shadow.
Contrast-enhanced CT scan of the neck showing a multi-septate cystic neck mass, lying superficial to the thyroid lobes and strap muscles.
Contrast-enhanced CT scan of the upper thorax showing extension of a complex cystic mass and displacement of the trachea with compression of major vessels.
The patient was operated upon through a neck crease and median sternotomy incision under general anesthesia with endotracheal intubation. The posterior wall of the mass in the neck was adherent to the strap muscles. A solid mediastinal tumour with areas of necrosis, which seemed to be arising from the thymus gland, was found on sternotomy. The tumor derived its blood supply from the thoracic vascular channels as direct branches from aortic arch and the subclavian artery. There were no vessels feeding or draining the tumor in the neck. The mass was adherent to but did not infiltrate, the innominate vein. The neck and thoracic mass, along with a densely adherent 4 × 3 cm area of left mediastinal pleura, were removed in continuity, preserving nearby vital structures.
The resected surgical specimen was subjected to a detailed histopathological evaluation. On naked eye examination, the globular brownish mass measured 16 × 7 × 2 cms. The cut surface of the mass was cystic, filled with yellow pultaceous material and a mass of hair. There was a solid area projecting into the lumen of the cystic area, which had multiple cysts filled with gelatinous material. On microscopy, the cyst wall showed predominantly degenerate necrotic area, associated with inflammatory cells. Sections from the solid areas revealed cartilage, osseous tissue and nerve bundles with ganglionic cells, respiratory epithelium and sero-mucinous glands embedded in dense fibro-collagenous and fibro-muscular tissue. The lesion was thus labeled as a mature cystic teratoma on basis of the histopathological features.
The patient made an uneventful postoperative recovery. After five years in the follow-up, the patient has remained asymptomatic, and follow-up imaging studies in the form of chest x-ray examination undertaken 3, 14 and 36 months after operation, as well as a contrast enhanced CT scan of the neck and mediastinum performed 14 months after operation, have not shown any residual or recurrent mass.