Retropharyngeal lipoma

Clinical History

67-year-old man presented with hoarseness of voice, breathlessness, foreign body sensation in the throat during the past 2 months. He had a history of mouth breathing, snoring at night, but no sleep apnoea. His symptoms increased on flexing the neck.

Imaging Findings

Lateral cervical spine X-ray (Fig. 1) shows prevertebral soft tissue widening, extending superiorly from C2 vertebral level and merging with the mediastinum inferiorly.

MDCT neck with contrast (Fig. 2, 3) shows a retropharyngeal fat density lesion extending superiorly from the anterior border of C2 vertebral level and inferiorly up till the anterior border of T3 vertebral body. Laterally the lesion is seen to displace the contrast opacified internal jugular and carotid artery laterally. Multiple thin wispy soft tissue attenuated septa are seen within the lesion, however, without any enhancing focus.

Discussion

Background

Lipomas are one of the most common soft-tissue mesenchymal tumours. They may arise in almost all parts of the body. Their occurrence in the head and neck, however, is relatively rare [1]. Various lipomatous subtypes such as infiltrative [2] and ossifying [3] have been described.

Clinical perspective

Retropharyngeal lipomas are slow growing tumours that attain a large size before they manifest clinical symptoms. The usual presentations are dyspnoea, dysphonia, dysphagia in particular for solid foods, obstructive sleep apnoea [4] etc. Clinical diagnosis may be difficult; however, imaging using CT/MRI will reveal the underlying pathology.

Imaging perspective

On CT, lipomas appear as a homogeneous hypodense mass, sometimes with thin and wispy soft-tissue attenuated septations, although, on occasion, septa may be thick and nodular. They have fat attenuation and do not typically show contrast enhancement. In some cases, centrally enhanced areas, corresponding to lipomatous lesions with inflammatory cell infiltration, have been identified [5]. It is difficult to differentiate well-differentiated liposarcoma from benign lipoma, however, broader and more nodular fibrous septa is seen more in former than the latter although pathological evaluation is required for confirmation of diagnosis [6].

MR images: on T1-weighted images lipomas have high signal intensity and on T2WI it appears hyperintense, however, less bright than T1WI. Fat is also suppressed with the use of fat-suppression sequences.

IV administration of contrast medium help in improving the delineation of tumours as well as revealing areas of viable vascularized tumour [6]. Definite diagnosis of retropharyngeal lipoma is by histo-pathological confirmation.

Therapeutic option and prognosis

Surgical excision is the treatment of choice. Orotracheal intubation may sometimes be difficult during surgery [7].

Differential Diagnosis List

Final Diagnosis

Retro-pharyngeal lipoma

URL:	https://www.eurorad.org/case/10772
DOI:	10.1594/EURORAD/CASE.10772
ISSN:	1563-4086