Neural fibrolipoma in pharyngeal mucosal space: A rare occurrence
A 12-year-old male child presented to the outpatient department of otorhinolaryngology with history of mass in the oral cavity since birth. The child complained of difficulty in breathing and swallowing for last 2 years. On physical examination, there was a soft lobulated non-tender mass with smooth margins and overlying congested mucosa and surface nodularity in the right side of oral cavity and oropharynx, displacing the soft palate to the left Indirect laryngoscopic examination was not feasible, and on direct laryngoscopy, the lesion was seen extending into the hypopharynx and the right pyriform sinus. The epiglottis, pre-epiglottis space, and the left pyriform sinus appeared normal.\nPlain radiograph, soft tissue neck showed a broad-based radio-opacity arising from the posterior pharyngeal wall, extending from the C4 to C6 cervical vertebral level, compressing the airway anteriorly. The underlying bones appeared normal with no evidence of widening of the prevertebral soft tissue.\nContrast-enhanced CT scan of the neck revealed a well-defined (6 cm × 2 cm), hypodense mass lesion with predominant fat attenuation (mean attenuation: –50 HU) with linear intersecting soft tissue attenuation areas showing minimal contrast enhancement in the right pharyngeal wall, extending from the nasopharynx up to the level of hypopharynx] [Figure and ]. Mass effect was noted in the form of compression of airways with displacement of soft palate and the overlying enhancing mucosa to the left, with lateral displacement of prestyloid fat plane confirming the location of the lesion in the right pharyngeal mucosal space. Bilateral carotid-jugular vessels were normal in caliber and position.\nOn MRI examination, the mass in the right pharyngeal mucosal space was hyperintense on T1 and T2 sequences with few linear areas of hypointensity [Figure and ] with homogenous suppression of the hyperintense areas of mass on fat-suppressed STIR sequence [].\nBased on the clinical and imaging findings, a diagnosis of a fat containing tumor in right pharyngeal mucosal space was made with possibilities of lipoma, fibrolipoma and its variant, low-grade liposarcoma, and teratomas.\nA 6.5 × 3 cm, ovoid smoothly marginated firm mass with surface nodularity was excised after splitting the oropharyngeal mucosa] and the location of lesion in pharyngeal mucosa was confirmed. The postoperative period was uneventful and child was started on oral feeding on 3rd postoperative day.\nHistopathologic examination revealed a lipomatous lesion with intersecting spindle cells [Figure and ], which was analyzed by immunohistochemistry. The given pathological specimen was positive for S-100, confirming the neural origin, and the final diagnosis of neural fibrolipoma in right pharyngeal mucosal space was established.