Retropharyngeal Space Lipomas. A Systematic Review of the Reported Cases in the Literature

Retropharyngeal space lipomas (RSLs) comprise a group of very uncommon head and neck benign, soft tissue tumors that originally grow in the retropharyngeal space. They can develop as individual tumors or in the context of syndromic lipomatosis. Symptoms usually arise as expanding RSLs exert pressure on adjacent structures, and clinical manifestations are often atypical and overlapping. Given the rarity of this diagnosis, current evidence is scarce, providing a rather fragmented picture. A literature search was conducted in all major medical databases, without time limitations. Tumors were considered RSLs if a benign lipomatous tumor appeared to develop originally in the retropharyngeal space. Cases with syndromic lipomatosis that demonstrated at least one such tumor involving the retropharyngeal space were included. A total of 52 publications concerning 79 eligible cases were found. Two of these cases concerned patients with Multiple Symmetrical Lipomatosis. A male predominance was found (61.5%, n = 48). Dysphagia (65.2%, n = 43) was by far the most common symptom, followed by snoring (37.9%, n = 25), dyspnoea (34.8%, n = 23) and dysphonia (30.3%, n = 20). The most used imaging modality was Computed Tomography (CT) (64.1%, n = 41). Surgery was the treatment in 73 cases (93.6%). The transcervical was the most selected approach (50.7%, n = 37), followed by the transoral approach (38.4%, n = 28). Complete recovery was reported, following treatment, in 60 cases (75.9%). Retropharyngeal space lipomas are benign tumors with a higher prevalence in male patients. Dysphagia is the most common symptom. Imaging is necessary for diagnosis, with CT scanning being usually sufficient as a single modality test. More than half of the patients in the literature are treated via an external approach. Diminishing of symptoms and full postoperative recovery is the most common outcome.