Hypopharyngeal lipoma-A diagnostic work up.

It is important to examine the pharynx through nasoendoscopic examination in patients that present with dysphagia, to look for pharyngeal masses. Magnetic resonance imaging can accurately diagnose lipoma in the pharynx region.

QUESTION

A 63‐year‐old man presented with food regurgitation, dysphagia, and weight loss. Examination of oral cavity and neck revealed no abnormalities. Flexible nasoendoscopy (Figure 1A) and magnetic resonance imaging (MRI) revealed a spherical smooth midline mass in the hypopharynx. Initial Computed Tomography (CT) of neck, thorax, and abdomen did not report any abnormalities. What is the diagnosis?

Figure 1

A, Flexible nasoendoscopic view of lipoma. B, Excised lipoma specimen

ANSWER

Lipomas comprise of 0.6% benign upper aerodigestive tumors.1 The symptoms vary depending on the size; from asymptomatic, dysphagia, obstructive sleep apnea to airway compromise. In any patient with presenting with dysphagia, it is worth considering examining the pharynx as well as the esophagus, through nasoendoscopic examination. Differential diagnosis of lumps in this region includes mainly malignant neoplasm, other possibilities include retention cysts.2 Diagnosis is through examination with flexible nasoendoscopy and imaging. Endoscopy has limits, as the origin and extent of the mass cannot be fully assessed. On CT scan, fat tissue is homogeneous with a low attenuation value and a density lower than that of water (<0 hounsfield units).2 However, it is difficult to identify the origin of the mass. In this case, the mass was missed on the CT initially (Figure 2). MRI is favorable to CT due to its superiority in delineating and characterizing soft tissue. It also has no radiation. It can reveal the origin in relation to surrounding structures. Lipoma typically appears hyperintense on T1‐ and T2‐weighted images and hypointense in fat‐suppressed contrast images (Figure 3). MRI is able to narrow the diagnosis to lipoma by identifying its fatty nature. Once the MRI identifies the extent and origin of the lesion, surgical excision can be planned out (Figure 1B).

Figure 2

Axial CT image showing the hypodense (−75 hounsfield units) lipoma in the hypopharynx. Arrow pointing to the mass

Figure 3

Sagittal T2‐weighted image (A), coronal T1‐weighted image (B) and axial T1‐weighted image (C) of lipoma in the hypopharynx showing a hyperintense lesion. Axial STIR image (D) showing fat suppression of the lesion, compatible with a lipoma

CONFLICT OF INTEREST

None declared.

AUTHORSHIP

WJ: was involved in writing the manuscript. AN: was involved in the care of the patient, obtaining consent, and reviewing the manuscript. RL: was involved in reporting the radiological images of the patient and reviewing the manuscript.

FUNDING

Imperial College London granted an open access fund for the publication of this article.