Esophageal Lipoma and Liposarcoma: A Systematic Review

Esophageal lipomatous tumors are uncommonly diagnosed and account for less than 1% of all benign esophageal neoplasms [1‐3]. They can present as an intramural submucosal mass, or as an intraluminal mass with a long and narrow pedicle covered by intact mucosa and tethered to the cervical esophagus. The pedicle is usually vascularized, can be quite mobile in the esophageal lumen, and may reach into the stomach [4‐6]. It is speculated that lipomas originating from the cervical esophagus near the cricopharyngeus tend to elongate and to assume a polypoid shape due to looseness of the submucosa and the long-lasting traction effect of esophageal peristalsis [3, 5, 7]. Despite esophageal lipomas are also described and reported as fibrovascular polyp, fibrolipoma, or angiolipoma [7], these neoplasms consistently share the presence of variable amounts of mature adipocytes and fibrovascular septa [4]. Due to their indolent growth pattern [8], most esophageal lipomas are estimated to be clinically silent and are incidentally found on radiographic imaging [2, 3]. In contrast, lipomas over 4 cm in size present with dysphagia, regurgitation, and/or respiratory symptoms [9]. Recurrent and life-threatening asphyxia due to oral prolapse of a mobile intraluminal lipoma is a bizarre clinical manifestation that can lead to sudden death from asphyxia [5, 6, 10]. The diagnosis is essentially based on upper gastrointestinal endoscopy, barium esophagogram, and computed tomography [11]. Excision of esophageal lipomatous tumors can be performed extraluminally, through an esophagotomy, or endoluminally through an endoscopic approach [11‐13]. Liposarcoma is extremely rare, although some neoplasms presenting as giant fibrovascular polyps have been diagnosed as liposarcomas on histopathological assessment [14].

The aim of this study was to provide a comprehensive and updated systematic literature review on the clinical-pathological features and therapeutic approach to esophageal lipomatous tumors.

An extensive literature search was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) statement [15]. Two independent authors (DF, DB) conducted the literature search to identify all English-written reports on esophageal lipoma and liposarcoma. Pubmed, Embase, Cohcrane, and Medline databases were accessed to May 1, 2020, using Google Chrome browser (Google, California, USA). The following specific MeSH keywords were used: esophagus; lipoma; polyp; fibrolipoma; angiolipoma; liposarcoma. The references list of each selected article was consulted to broaden the search. Articles where included in the research database if they reported a case of lipoma, fibrovascular polyp, fibrolipoma, angiolipoma, or liposarcoma of the esophagus in the adult or pediatric population. Tumors proximal to the cricopharyngeus were excluded. Non-English written articles and abstracts were excluded from final analysis (Fig. 1). Three authors (DF, DB, VL) independently extracted data from the appropriate studies, including author name, year, journal of publication, number of patients, age, sex, symptoms, diagnosis, location, morphology, size, therapeutic approach, histological findings, and adverse events. The methodological quality of the studies was assessed based on the most critical factors that increase the risk of bias in this specific context [16].

Inter-rater reliability was assessed for study selection and extraction of data using Cohen’s kappa coefficient. In case of disagreements between the authors, discussion and agreement were required; if consensus was not reached, a senior author (LB) made the decision.

Sixty-five case reports, [1, 2, 5, 6, 8, 10, 12, 13, 17‐73] and two reviews [11, 74], published between 1955 and May 2020, were included in the systematic review. The total number of patients was 239, including 176 with lipoma and 63 with liposarcoma. All studies had a retrospective design, and a low (n = 59) to moderate risk (n = 8) for bias based on a global assessment of methodological quality [16].

The present systematic review shows that the vast majority of esophageal lipoma is represented by fibrovascular polyps originating from the cervical esophagus. All adverse events related to the natural history of esophageal lipoma or to the consequences of therapeutic intervention occurred before the 1980′, reflecting in part limited use of radiological imaging that may have accounted for late diagnosis. In fact, five patients required emergent tracheotomy or intubation, and 7 of 11 untreated patients died of asphyxia, thus underscoring the importance of early diagnosis and endoscopic treatment [27].

After the 1980s, there has been a shift toward first-line endoscopic excision of fibrovascular polyps, and this procedure has largely replaced open cervical esophagotomy. Since the review of Caceres et al. [11], the rate of cervical lipoma approached through endoscopy has grown from 21.5 to 46% (p < 0.01).

Today, thanks to technological advancements, flexible endoscopy is the first-line approach even in patients with giant fibrovascular polyps. The risk of bleeding from the area of mucosal transection and from the central vascular axis of the polyp is minimal if the stalk is visible and a snare device can be easily applied. In some circumstances, a cross-over approach with rigid endoscopy could be crucial to avoid open surgery. A recent meta-analysis comparing flexible and rigid endoscopy showed that both approaches were safe and effective for retrieval of upper esophageal foreign bodies [75]. The Weerda diverticuloscope, commonly used for the treatment of Zenker diverticulum, allows to introduce a rigid 5-mm telescope along with multiple devices, such as graspers, forceps or endo-staplers [30].

When the snare technique is not feasible because of the difficulty of trapping the polyp stalk or the risk of an incomplete resection, endoscopic submucosal dissection (ESD) is another option that has been shown to be safe even in patients with giant fibrovascular polyps [5, 53, 63]. Compared to the snare technique, ESD can increase the chance of a radical excision of the polyp with clear margins. In the present systematic review, there were 5 reported recurrences or malignant transformations after initial snare excision of an apparently benign lipoma. Unfortunately, the resection margin was not evaluated [11, 12]. Two studies reviewing the clinical-pathological and molecular features of esophageal lipoma and liposarcoma found MDM2 amplification by fluorescence in situ hybridization in all cases, with some of these patients presenting recurrent disease [14, 76]. Therefore, a careful histopathological assessment of the resection margin, is recommended after resection of an apparently benign lipoma, and patients should be advised about the need for endoscopic/radiologic surveillance. Given the potential malignancy of esophageal lipomatous neoplasms, we suggest an algorithm for diagnosis, treatment, and surveillance (Fig. 5).

The rarity of esophageal lipoma, the heterogeneity of reported data, the differences in histopathological assessment and classification, and the therapeutic selection bias are the main study limitations.

In conclusion, esophageal lipoma is an uncommon but potentially life-threatening condition. Clinical presentation and treatment remain heterogeneous in the literature. For polyps of the upper esophagus, early intraluminal approach by flexible or rigid endoscopy and careful histopathological assessment is recommended. Distal esophageal and intramural lesions may safely and effectively be approached by laparoscopy or thoracoscopy to reduce patient hospitalization and potential morbidity related to open surgery.