Liposarcoma

Liposarcoma is one of the most common neoplasms of adulthood. However, it is exceedingly rare in the gastro-intestinal tract. To our knowledge, only 12 cases occurring in the esophagus have been reported in the world literature to date. We report the case of a 42-year-old man with a pleomorphic liposarcoma arising in the esophageal wall. The morphologic, immunophenotypic, and ultrastructural characteristics are presented, as well as the results of literature review.

(Arch Pathol Lab Med. 2004;128:922-925)

Liposarcoma, the most common soft tissue sarcoma, represents 20% of the mesenchymal malignancies and tends to occur in the retroperitoneum and deep soft tissues of the trunk and extremities. It infrequently arises in the gastrointestinal system, and esophageal liposarcoma is extremely rare. Primary liposarcoma of the esophagus was initially reported in 1983 by Mansour et al.1 Our review of the literature revealed that only 12 cases have been reported to date.'"12 We describe a patient who was found to have a high-grade pleomorphic liposarcoma arising in the esophageal wall. To our knowledge, this represents the 13th case reported in the literature and the first case of pleomorphic liposarcoma.

REPORT OF A case

The patient was a 42-year-old man who presented with dysphagia, persistent nausea, vomiting, and a 13.6-kg weight loss in 3 months. Physical examination showed no masses in the chest, abdomen, or extremities. An initial upper gastrointestinal endoscopy showed a partially obstructing, 10-cm submucosal mass in the distal esophagus with a nonulcerating overlying mucosa. The gastroesophageal junction and gastric mucosa were normal. Computed tomographic scan of the chest with intravenous contrast showed a well-circumscribed, large, heterogeneous mass of low attenuation (Hounsfield units ranged from 2 to 11) that was located in the retrocardiac region and was inseparable from the esophagus (Figure 1). Computed tomographic scan of the abdomen showed no abdominal masses.

Due to the severe dysphagia, a Dobhoff nasojejunal feeding tube was placed to administer nutritional support. An incisional biopsy was planned, but the patient had upper gastrointestinal bleeding and was scheduled for surgery instead. Intraoperatively, a large necrotic esophageal mass was identified, which was inadvertently perforated; some tumor fragments were spilled, requiring posterior irrigation of the bilateral pleural cavities. The patient underwent a transhiatal total esophagectomy with gastric pull-up through the posterior mediastinum and cervical esophagogastric anastomosis. Histologie examination showed a pleomorphic liposarcoma. In the immediate postoperative period, the patient developed pulmonary edema, bilateral pleural effusions, and pneumonia secondary to Klebsielln pneumoniae and Candida albicans. he was treated with piperacillin-tazobactam, fluconazole, and vancomycin. After recovering, the patient was discharged on the 29th postoperative day and was scheduled to receive chemotherapy on the second month.

PATHOLOGIC FINDINGS

Gross Findings

The resected specimen consisted of the esophagus, which measured 21.5 cm in length and 2.5 cm in diameter, with an attached 8.0-cm portion of the stomach. A 10.5 × 7.0 × 5.5-cm, ulcerated, friable, white-tan and yellow, focally necrotic mass was noted in the distal esophagus, 3.5 cm above the gastroesophageal junction. The diameter of the mass narrowed as it approached the adventitia, which was perforated, and the tumor was present at the deep margin. The gastroesophageal junction and adjacent stomach were unremarkable (Figure 2).

Histologie Findings

The rumor had characteristic features of a liposarcoma, including multivacuolated lipoblasts with hyperchromatic nuclei and a solid pattern of growth in a background of a rich vascular network. These areas were contiguous with zones of pleomorphic liposarcoma in which the lipoblasts had bizarre scalloped nuclei (Figure 3, a and b). More anaplastic features were also noted, containing markedly enlarged multinucleated cells with irregular vesicular nuclei and little or no obvious lipid accumulation. In some areas, the cells had a spindle cell configuration and were associated with extensive necrosis admixed with giant cells, resembling a malignant fibrous histiocytoma (MFH) (Figure 3, c). The mitotic activity in this pleomorphic liposarcoma ranged from 5 to 15 mitoses per 10 high-power fields. Lymphovascular invasion was identified.

lmmunohistochemical Findings

Tissue sections were immunostained by an indirect biotin-avidin method in a Dako Autostainer Plus (Dako, Carpinteria, Calif) with the following panel of antibodies: SlOO (Dako, 1:500, rabbit), c-Kit/CD117 (Dako, 1:400, rabbit), HMB-45 (Dako, 1:50, mouse), Melan A (Dako, 1:50, mouse), desmin (Dako, 1:500, mouse), CD68 (Dako, 1: 2000, mouse), and cytokeratin cocktail (AE1/AE3: Dako, 1:200, mouse; high-molecular weight: Dako, 1:500, mouse; and CAM 5.2: Becton Dickinson, San Jose, Calif, 1:1500, mouse). The tumor was only positive for SlOO in the better-defined lipoblasts. In all areas, the tumor was negative for c-Kit, HMB-45, Melan A, and desmin. The more pleomorphic areas were focally positive for CD68 and showed rare cytokeratin-positive cells.

Ultrastructural Findings

The ultrathin formalin-fixed sections were examined with a JEOL CX-IOO transmission electron microscope. The cells exhibited large, deeply indented nuclei with prominent nucleoli, irregular nuclear membranes, and variable amounts of non-membrane-bound intracytoplasmic lipid droplets of different size and density (Figure 4). Within the giant cells, rare eosinophilic hyaline globules were also observed, which represent a nonspecific degenerative feature of the poorly differentiated neoplasms. There were no desmosomes or other cellular attachments, but numerous pinocytic vesicles and lysosomes were observed.

COMMENT

Primary liposarcoma of the esophagus is exceedingly rare. To our knowledge, only 12 cases have been reported in the world literature1-12 since the first description by Mansour et al in 1983.] Our case represents the 13th case and the only such case to be presented in the pathology literature. The clinicopathologic information for these patients and their tumors is summarized in the Table. The patients ranged in age from 43 to 73 years (mean, 587 .7 years; median, 56 years) with a male-female ratio of 1.16: 1, which is consistent with the slight male predominance observed in the soft tissue liposarcomas. The predominant clinical symptoms included progressive dysphagia, nausea, throat discomfort, and foreign body/lump sensation. Other patients also presented with recurrent vomiting followed by extrusion of the mass through the mouth,11 vomit of tumor fragments,5 cough, and weight loss. Most tumors (84.6%) were located in the upper esophagus. In most (92.3%) of the reported cases, the tumor consisted of an intraluminal, polypoid, yellow to gray-tan mass, and the resected specimens ranged in greatest dimension from 4 to 23 cm (mean, 12.8 cm). To our knowledge, ours is the first reported case of primary liposarcoma presenting with a transmural esophageal mass. Among the 12 cases reported in the literature as liposarcoma of the esophagus, 5 (38.4%) were subclassified as myxoid and 7 (53.8%) were well differentiated. Unfortunately, microscopic illustrations were not shown in 4 cases.1,3,10,12 However, the descriptions were consistent with the diagnoses. Our case is the only case of a pleomorphic liposarcoma.

The immunohistochemical profile was reported in 3 cases (including ours) and showed some lipoblasts to be immunoreactive to SlOO antibody. In our case, positive staining for SlOO was seen only in the better-differentiated areas of the tumor. The pleomorphic zones were negative for SlOO. The latter is a feature that has been described in soft tissue, as SlOO immunostain is positive in the adipocytic differentiated areas of a liposarcoma, but the stain is less frequent in the pleomorphic zones. Among the esophageal liposarcomas, ultrastructural analysis was performed in only 1 other reported case of a myxoid liposarcoma in which the lipoblasts contained intracytoplasmic nonmembrane-bound lipid droplets of different sizes and densities in addition to undifferentiated mesenchymal cells.7 Nine (69.2%) of the 13 lesions were resected by simple excision transecting the stalk of the tumors, whereas subtotal or total esophagectomy was deemed necessary in only 4 cases. Two tumors (15.3%) recurred after 6.5 and 25 years; in the latter, however, the histology of the initial lesion was never documented." The mean disease-free interval for the entire group of patients was 127 .87 months (range, 2-30 months). No metastases have been documented.

Our report represents the first documented case of primary esophageal pleomorphic liposarcoma. Pleomorphic liposarcomas usually develop late in adult life, with a peak incidence during the sixth and seventh decades. Most occur in the deep soft tissues of the proximal extremities, especially the thigh. These tumors present as large masses ranging in color from white-tan to brownyellow. The lipogenic component contains giant multinucleated lipoblasts with hyperchromatic bizarre nuclei and multiple cytoplasmic lipid vacuoles, giving a grapelike appearance. The nonlipogenic component can resemble a pleomorphic and/or myxoid MFH, a round cell liposarcoma, a spindle liposarcoma, and/or an epithelioid carcinoma.13 Our case had areas that resembled MFH. Such a degree of pleomorphism may explain why our case presented as a transmural mass instead of a polyp, which was the presentation in all of the previously reported cases. In different studies, the disease-related mortality varies from 35% to 50%. They have a high local recurrence rate (from 21% to 45%) that is usually associated with incomplete excision. Their metastatic rate ranges from 29% to 44%.13

The differential diagnoses include malignant gastrointestinal stromal tumor and leiomyosarcoma. Both types of tumor occur in the submucosa and grow toward the lumen, causing clinical symptoms similar to those of liposarcomas. Gastrointestinal stromal tumors are well-circumscribed, smooth, lobulated, or whorled masses with focal hemorrhage and/or cystic degeneration. They are usually composed of plump spindle cells immunoreactive to CD34 and c-Kit (CD117).14 Leiomyosarcoma is the most frequent type of sarcoma in the esophagus; however, it accounts for only 5% of all esophageal malignancies. Histologically, these tumors show intersecting fascicles of spindle cells with blunt-ended nuclei, variably eosinophilic cytoplasm, significant mitotic activity, and immunoreactivity to smooth muscle actin and desmin.14 The possibility of an anaplastic carcinoma could be also considered, but in our case the overlying esophageal mucosa did not show any preneoplastic changes. In addition, the cytokeratin stain was only very focally positive on individual cells of the overtly pleomorphic areas that resembled MFH. Malignant fibrous histiocytomas have been shown to display cytokeratin immunoreactivity in up to 10% of cases.15 Lastly, a giant fibroepithelial polyp of esophagus must be included in the differential diagnosis when dealing with polypoid intraluminal lesions. The giant fibroepithelial polyp is a large pedunculated mass that originates in the upper esophagus and extends distally, sometimes all the way to the esophagogastric junction. Its clinical manifestations include regurgitation of the mass through the mouth, dysphagia, and weight loss. The mass is usually covered by normal mucosa and has an edematous or myxoid cut surface. Microscopically, it has a mixture of collagenized vascular tissue, clusters of adipocytes, and myxoid areas with spindle cells resembling a well-differentiated or myxoid liposarcoma. The tumor can be removed through a cervical esophagotomy by an amputation of the base.14 Interestingly, the clinical presentation, location, type of excision, and pathologic description of some of the previously reported cases of esophageal liposarcoma are very similar to those of a giant fibroepithelial polyp.

The authors thank Carlos Fajardo for his technical assistance in electron microscopy, Hideo Yoshida, MD, for translating an article published in Japanese, and Joyce Bruce, MD, for her editorial assistance.

References

1. Mansour KA, Frits RC, Jacobs DM, Vellios F. Pedunculated liposarcoma of lhe esophagus: a first case report. J Thorac Cardiovasc Surg. 1983:86:447-450.

2. Bak YT, Kim |H, Kirn JG, et al. Liposarcoma arising in a giant lipomatous polyp of the esophagus. Korean 1 Intern Med. 1989;4:86-89.

3. Yates SP, Collins MC. case report: recurrent liposarcoma of the esophagus. CUn Radio!. 1990:42:356-358.

4. Baca I, Klempa I, Weber JT. Liposarcoma of the esophagus. Eurl Surg Oncol. 1991:17:313-315.

5. Masumori K, Yoshioka M, Tanaka Y, et al. A case report: esophageal liposarcoma. Nippon Ceka Gakkai Zasshi. 1991;92:885-888.

6. Cooper CJ, Boucher NR, Smith JH, Thorpe JA. Liposarcoma of the esophagus. Ann Thorac Surg. 1991;51:1012-1013.

7. Boggi U, Viacava P, Naccarato AG, et al. Giant pedunculated liposarcomas of the esophagus: literature review and case report. Hepatogastroenterology. 1997;44:398-407.

8. Salis GB, Albertengo JC, Bruno M, et al. Pedunculated liposarcoma of the esophagus. Dis Esophagus. 1998:11:68-71.

9. Mandell DL, Brandwein MS, Woo P, Som PM, Biller HF, Urken ML. Upper aerodigestive tract liposarcoma: report on four cases and literature review. Laryngoscope. 1999:109:1245-1252.

1O. Ruppert-Kohlmayr AJ, Raith J, Friedrich G, Reagauer S, Preidler KW, Szolar DH. Giant liposarcoma of the esophagus: radiological findings. I Thorac Imaging. 1999;14:316-319.

11. Beaudoin A, Journet C, Watier A, Mongeau CJ, Chagnon M, Beaudry R. Giant liposarcoma of the esophagus. Can I Castroenterol. 2002;16:377-379.

12. Chung JJ, Kim MJ, Kim JH, Lee JT, Yoo HS, Kim KW. Imaging findings of giant liposarcoma of the esophagus. Yonsei Med J. 2003;44:715-718.

13. Gebhard S, Coindre J-M, Michels J-J, et al. Pleomorphic liposarcoma: clinicopathologic, immunohistochemical, and follow-up analysis of 63 cases. Am I Surg Pathol. 2002:26:601-616.

14. Lewin K, Appelman H. Mesenchymal tumors and tumor-like proliferations of the esophagus. In: Rosai J, Sobin L, eds. Tumors of the Esophagus and Stomach. Washington, DC: Armed Forces Institute of Pathology; 1996:150-158. Atlas of Tumor Pathology; 3rd series, fascicle 18.

15. Miettinen M, Soini Y. Malignant fibrous histiocytoma: heterogeneous patterns of intermediate filament proteins by immunohistochemistry. Arch Pathol Lab Med. 1989:113:1363-1366.

Monica Garcia, MD; Efren Buitrago, MD; Pablo A. Bejarano, MD; Javier Casillas, MD

Accepted for publication March 26, 2004.

From the Departments of Pathology (Drs Garcia and Bejarano), Surgery (Dr Buitrago), and Radiology (Dr Casillas), University of Miami School of Medicine, Miami, FIa.

The authors have no relevant financial interest in the products or companies described in this article.

Reprints: Pablo A. Bejarano, MD, Department of Pathology, University of Miami School of Medicine, Jackson Memorial Hospital, 1611 NW 12th Ave, Holtz Tower, Room 2042, Miami, FL 33136 (e-mail: pbejaran@med.miami.edu).

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