Recurrent laryngeal cancer after total laryngectomy

Clinical History

This patient, with a history of laryngeal cancer treated by radiotherapy and later total laryngectomy because of recurrent tumour, now presents with dysphagia.

Imaging Findings

The patient had been diagnosed with supraglottic squamous cell carcinoma, extending into the base of the tongue, 1.5 year previously. Treatment was by radiotherapy with curative intent. Nine months later, total laryngectomy, with partial resection of the tongue base, was performed due to recurrent tumour.

The patient presented with dysphagia. Clinical examination showed some (aspecific) mucosal abnormalities in the neopharynx. The patient was referred for a CT study of the neck, looking for evidence of tumour recurrence.

Discussion

The CT study showed the expected changes after total laryngectomy, radical neck dissection, and flap reconstruction. Total laryngectomy is a surgical procedure used for primary treatment of advanced, large volume cancers, and as salvage procedure for recurrent cancer initially treated by radiotherapy. When the larynx is removed, the airway and upper digestive tract become completely separated. The airway will then end at a tracheostomy in the base of the neck. If, following the laryngectomy, insufficient (hypopharyngeal) tissue is left for creating a neopharyngeal lumen of acceptable diameter, a soft tissue flap is used to create a wider lumen. A pedicled pectoralis major musculocutaneous flap is commonly used for this purpose. The skin of the flap borders the lumen, while the bulk of the flap fills the soft tissue neck defect, creating a more acceptable aesthetic appearance.

Commonly during laryngectomy, tissue of the thyroid gland is removed. Unilateral thyroidectomy may be performed, to facilitate surgical access to the larynx and to remove at the same time a site of potential direct spread of the cancer. Another option is to remove the isthmus of the thyroid gland, leaving the two thyroid lobes, as in this case. This remnant thyroid tissue is usually easy to recognise because it shows a high density, related to the high iodine concentration in the gland and its strong vascularisation. However, the normal shape of the thyroid gland is lost, and these remnants usually show a rounded or oval appearance. Thyroid tissue may appear inhomogeneous due to the presence of nodular hyperplasia, adenomas or cysts. It is important that these thyroid remnants are not confused with recurrent cancer; unlike recurrent cancer, they have well-defined borders.

Furthermore, a number of expected changes after radiotherapy are seen in this patient, such as increased enhancement of the right submandibular salivary gland due to radiation sialadenitis. Care should be taken not to misinterprete this as an adenopathy, especially as the left submandibular salivary gland was resected (as is commonly done in neck dissections).

Apart from these expected changes, an infiltrating tumour mass in the floor of the mouth and tongue base, reaching the proximal anastomosis of the neopharynx and oropharynx, is demonstrated. Although in most cases after total laryngectomy, the clinician is able to detect tumour recurrence by endoscopic examination, imaging is valuable to define the precise anatomical tumour extent. In some cases, a surgical salvage procedure can be performed. However, in this particular case, because of the extensive growth in the tongue and floor of the mouth, palliative (chemotherapeutic) therapy was started.

Differential Diagnosis List

Final Diagnosis

Recurrent laryngeal cancer after total laryngectomy

URL:	https://www.eurorad.org/case/1359
DOI:	10.1594/EURORAD/CASE.1359
ISSN:	1563-4086