Discussion
Liposarcoma is the most common soft tissue malignant tumor in adults and usually occurs in the retroperitoneum, deep soft tissues of the trunk, or lower extremities. It is very rare in the gastrointestinal tract, especially in the esophagus [5]. In PubMed search using the words “liposarcoma” and “esophagus,” we found only 33 reports from 1983 to 2015. Including two cases from our facility, we reviewed 35 cases of esophageal liposarcoma. The average age was 58.4 years, and the male-to-female ratio was approximately 3:1. The average size was 13.3 cm (range, 4–27 cm), and the most common symptom was dysphagia (88.6 %) (Table 1).
Characteristics of patients with esophageal liposarcoma
WDL well-differentiated liposarcoma, DDL dedifferentiated liposarcoma, ML myxoid liposarcoma, PL pleomorphic liposarcoma, NA not available
aSome patients had several symptoms
Our patient, conversely, complained of severe dyspnea resulting from compression of the membranous portion of the trachea by the huge tumor. Therefore, tracheotomy was required for airway management. None of the patients with esophageal liposarcoma reported in the literature had similar airway compression. There are, however, reports of sudden asphyxia due to pedunculated polyps of the esophagus or pharynx [6].
Since tumor resection is the only curative treatment for liposarcoma [7, 8], such lesions in the esophagus are usually surgically or endoscopically removed. Of the 35 cases we reviewed, surgical resections, either polypectomy or esophagectomy, were performed in 30 patients (85.7 %), endoscopic polypectomy in three (8.6 %), and ESD in two (5.7 %). The average tumor size was 15.2 cm for cases resected by total esophagectomy and 6.7 cm for those removed by endoscopic polypectomy; so the larger the tumor, the more likely the need for surgery.
Liposarcoma originates from a primitive mesenchymal cell and usually arises from the esophageal mucosa and submucosa [9, 10]. According to the literature review, 94 % or reported tumor was polypoid, and 68 % arose from the cervical esophagus (Table 1). When the base of the tumor is clearly demonstrated endoscopically, ESD enables curative resection by removing the tumor base. Intraoperative pathology examination may help to confirm negative surgical margins. In our patient, ESD successfully removed the tumor, but the entire lesion was too large to be removed through the mouth. Performing esophagotomy through a neck incision after ESD allowed the tumor to be removed in its entirely without subsequent compromise of swallowing or phonation.
Generally, the aggressiveness of soft tissue sarcoma differs depending on histologic type. Enzinger reported that the patients with well-differentiated liposarcoma in various organs had the highest 5-year survival and the lowest local recurrence rate [11]. But the prognosis after resection of an esophageal liposarcoma is unclear. To the best our knowledge, there have been only two reported cases of recurrence at 78 and 300 months after surgery [12, 13]. The tumors in these cases were well-differentiated, myxoid lesions. In those two cases, there was no information on the surgical margins. In general, esophageal liposarcoma is a slow-growing tumor [12], so a long period of follow-up may be advisable to detect late recurrence.