Levine2003.pdf

Benign Tumors of the Esophagus: Radiologic Evaluation Marc S. Levine Benign tumors of the esophagus can be classified as mucosal or submucosal in origin. The most common mucosal lesions include squamous papillomas, adenomas arising in Barrett’s mucosa, inflammatory esophagogastric polyps, and glycogenic acanthosis. These benign mucosal lesions can often be diagnosed on double-contrast esophagrams based on their characteristic radiographic findings. Major submucosal or intramural lesions include leiomyomas, leiomyomatosis, fibrovascular polyps, granular cell tumors, and duplication cysts. Despite their infrequency, these lesions also can often be diagnosed on esophagography and/or CT based on their characteristic radiographic findings. The purpose of this article is to review in some detail the radiographic features of these various benign tumors of the esophagus. © 2003 Elsevier Inc. All rights reserved.

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enign tumors of the esophagus comprise only about 20% of all esophageal neoplasms.1 Most are small, asymptomatic lesions that are detected fortuitously on barium studies or endoscopy. However, some patients may present with dysphagia, bleeding, or other symptoms. Depending on the site of origin in the esophageal wall, benign tumors may be classified as mucosal or submucosal. These two types of lesions have characteristic radiographic features that are discussed separately in the following sections.

Technique Esophagography is usually performed as a biphasic examination that includes both upright double-contrast views of the esophagus with a high-density barium suspension and prone singlecontrast views with a low-density barium suspension.2 The patient first ingests an effervescent agent and then rapidly gulps a high-density barium in the upright, left posterior oblique position to obtain double-contrast views of the esophagus. The patient is then placed in the prone, right anterior oblique position and asked to take disFrom the University of Pennsylvania School of Medicine, Gastrointestinal Radiology Section, Hospital of the University of Pennsylvania, Philadelphia, PA. Address reprint requests to Marc S. Levine, MD, Department of Radiology, Hospital of the University of Pennsylvania, 3400 Spruce Street, Philadelphia, PA 19104. © 2003 Elsevier Inc. All rights reserved. 1043-0679/03/1501-00003-0$30.00/0 doi:10.1016/S1043-0679(03)00003-0

crete swallows of a low-density barium to evaluate esophageal motility. Finally, the patient rapidly gulps a low-density barium to optimally distend the esophagus. The double-contrast phase optimizes visualization of the mucosa for detection of subtle neoplastic lesions, whereas the single-contrast phase optimizes esophageal distention for detection of subtle areas of narrowing. The double- and single-contrast components of the biphasic esophagram therefore have complementary roles in the evaluation of patients with suspected esophageal disease.

Mucosal Lesions Papilloma Squamous papillomas are uncommon benign tumors, comprising less than 5% of all esophageal neoplasms.3 These lesions consist of a central fibrovascular core with multiple finger-like projections covered by hyperplastic squamous epithelium.4 They usually occur as solitary lesions, ranging from 0.5 to 1.5 cm in diameter. Most patients are asymptomatic, but some with larger polyps may present with dysphagia. Multiple papillomas may be present in patients with a rare condition known as esophageal papillomatosis.5 Radiographic Findings Papillomas are difficult to detect on single-contrast esophagrams because of their small size. In contrast, papillomas can readily be detected on double-contrast esophagrams, appearing as small, sessile polyps with a smooth or slightly lobulated

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Adenoma Adenomas are rarely found in the esophagus because this structure is lined by squamous rather than columnar epithelium. However, esophageal adenomas may develop in metaplastic columnar epithelium associated with Barrett’s esophagus.8,9 These adenomas are important because they can undergo malignant transformation via an adenoma-carcinoma sequence similar to that found in the colon.8,9 Endoscopic or surgical resection is therefore warranted.

Figure 1. Squamous papilloma. Double-contrast esophagram shows a small, slightly lobulated papilloma etched in white (arrow) in the midesophagus. Early esophageal cancer could occasionally produce a similar appearance, so endoscopic biopsy specimens are required for a definitive diagnosis. (Courtesy of Harry Allen III, M.D., Norfolk, VA; reproduced with permission from Levine MS, Laufer I, Tumors of the esophagus, in Laufer I, Levine MS (eds), Double Contrast Gastrointestinal Radiology (ed 2), WB Saunders, Philadelphia, PA, 1992, pp 157-190)

contour (Fig 1).6 Occasionally, papillomas may be larger and more lobulated, or they may have a bubbly appearance as a result of trapping of barium between the frond-like projections of the lesion.7 Although papillomas are always benign, they cannot be differentiated with certainty from early esophageal cancers on radiographic criteria. Endoscopic biopsy or resection of the lesion is therefore required when a papilloma is suspected on barium studies. Despite its rarity, esophageal papillomatosis should be suggested by the presence of multiple discrete, wart-like excrescences on the esophageal mucosa (Fig 2).

Figure 2. Esophageal papillomatosis. Double-contrast esophagram shows multiple wart-like excrescences throughout the esophagus. Despite the dramatic radiographic findings, this patient had no esophageal symptoms. (Courtesy of Harvey M. Goldstein, M.D., San Antonio, TX; reproduced with permission from Levine MS. Benign tumors, in, Levine MS, Radiology of the Esophagus, WB Saunders, Philadelphia, PA, 1989, pp 113-130)

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Radiographic Findings Adenomas typically appear on esophagography as sessile or pedunculated polyps in the distal esophagus at or near the gastroesophageal junction (Fig 3).9 Lesions that are larger or more lobulated have a greater risk of harboring adenocarcinoma. Because of their location, adenomatous polyps can sometimes be mistaken for inflammatory esophagogastric polyps on the basis of the radiographic findings (see Inflammatory Esophagogastric Polyp section). When an adenoma is suspected on esophagography, however, endoscopy and biopsy are required for a definitive diagnosis.

Inflammatory Esophagogastric Polyp Although inflammatory esophagogastric polyps are not true neoplasms, they may be manifested

Figure 4. Inflammatory esophagogastric polyp. Prone single-contrast esophagram shows a prominent fold (straight arrows) extending from the gastroesophageal junction into the distal esophagus as a smooth polypoid protuberance (curved arrow). This lesion has the typical appearance of an inflammatory esophagogastric polyp.

on esophagography by polypoid lesions in the distal esophagus at or near the gastroesophageal junction.10-12 These lesions consist of a combination of inflammatory and granulation tissue and are presumed to develop as a sequela of chronic reflux esophagitis.11 Because esophagogastric polyps have no malignant potential, routine endoscopic resection of these lesions is not warranted.12 Radiographic Findings Figure 3. Adenomatous polyp in Barrett’s esophagus. Prone single-contrast esophagram shows a pedunculated polyp (arrows) extending from the gastroesophageal junction into the distal esophagus. The resected specimen revealed Barrett’s mucosa, with an adenomatous polyp containing a solitary focus of adenocarcinoma. (Reproduced with permission)9

Inflammatory esophagogastric polyps are usually manifested on barium studies by a single prominent fold that arises in the region of the gastric cardia and extends upward into the distal esophagus as a smooth, polypoid protuberance (Fig 4).10-12 These lesions are often best visualized

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on prone, single-contrast views of the esophagus during continuous drinking of a low-density barium suspension because the distal esophagus is optimally distended on these views. Because of its characteristic appearance and location, endoscopy is unnecessary when a typical inflammatory esophagogastric polyp is detected on barium studies. If the polyp has a lobulated contour or other atypical radiographic features, however, endoscopy and biopsy should be performed to exclude an adenomatous polyp in Barrett’s esophagus or other malignant lesions in the esophagus.

Glycogenic Acanthosis Glycogenic acanthosis is a benign condition of unknown cause in which there is accumulation of cytoplasmic glycogen in the squamous epithelial cells lining the esophagus, causing focal plaquelike thickening of the mucosa.13-15 Although glycogenic acanthosis is not considered to be a neoplastic condition, it is included in this review because it is characterized by mucosal nodules or plaques. Glycogenic acanthosis is a benign, degenerative condition, occurring primarily in the elderly.14 This condition rarely causes esophageal symptoms and is not associated with any known risk of malignant degeneration.16 As a result, it is usually discovered as an incidental finding on radiologic or endoscopic examinations. Radiographic Findings Glycogenic acanthosis is manifested on doublecontrast esophagrams by multiple small, rounded nodules or plaques in the middle or, less commonly, distal third of the esophagus (Fig 5).16,17 The nodules usually range from 1 to 3 mm in diameter, but occasional plaques can be as large as several centimeters in diameter.16,17 The major consideration in the differential diagnosis is Candida esophagitis (Fig 6). However, the plaques of candidiasis tend to have a more linear configuration and typically develop in immunocompromised patients with odynophagia,18 whereas glycogenic acanthosis occurs in older individuals who are not immunocompromised and have no esophageal symptoms. Thus, it is usually possible to differentiate these conditions on the basis of the clinical and radiographic findings.

Figure 5. Glycogenic acanthosis. Double-contrast esophagram shows multiple small, rounded nodules in the midesophagus. This was an elderly patient who had no esophageal symptoms. (Reproduced with permission from Levine MS. Benign tumors, in, Levine MS, Radiology of the Esophagus, WB Saunders, Philadelphia, PA, 1989, pp 113-130)

Submucosal Lesions By definition, all submucosal lesions arising in the wall of the esophagus are intramural. Not all intramural lesions are submucosal, however, as they can also arise from the muscularis propria or even the subserosa. Despite this distinction, the terms submucosal and intramural are used interchangeably based on long-standing convention.

Leiomyoma (Gastrointestinal Stromal Tumor) Leiomyomas (also known as gastrointestinal stromal tumors) are by far the most common benign submucosal tumors in the esophagus.3,19 These lesions consist of intersecting bands of

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smooth muscle and fibrous tissue surrounded by a well-defined capsule. Most esophageal leiomyomas are located in the thoracic esophagus below the level of the aortic arch because of the presence of striated rather than smooth muscle in the esophagus above this level. The vast majority of esophageal leiomyomas occur as solitary lesions, but multiple leiomyomas are present in 3% to 4% of cases.20,21 Most patients with esophageal leiomyomas are asymptomatic, but some may present with dysphagia, depending on the size of the lesion and how much it encroaches on the lumen. In contrast, gastrointestinal bleeding rarely occurs because leiomyomas in the esophagus, unlike those in the stomach, are almost

Figure 7. Leiomyoma. Double-contrast esophagram shows a smooth-surfaced mass (arrows) in the midesophagus. Note how this lesion has the typical radiographic features of a submucosal mass, forming slightly obtuse angles with the adjacent esophageal wall.

never ulcerated.22 Unlike stromal tumors elsewhere in the gastrointestinal tract, esophageal leiomyomas virtually never undergo sarcomatous degeneration. Thus, surgical removal of small esophageal leiomyomas in asymptomatic patients is probably not warranted. Radiographic Findings

Figure 6. Candida esophagitis. Double-contrast esophagram shows multiple plaque-like lesions in the esophagus. Note how the plaques have discrete borders and a predominantly linear configuration. This was an immunocompromised patient with odynophagia. (Reproduced with permission).18

When leiomyomas grow exophytically into the mediastinum, they can sometimes be recognized on chest radiographs by the presence of a mediastinal mass.23 Rarely, these tumors may contain punctate areas of calcification.24 Leiomyomas usually appear on barium studies as discrete, smooth-surfaced submucosal masses that form

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right angles or slightly obtuse angles with the adjacent esophageal wall when viewed in profile (Fig 7).19,22 These lesions may therefore be indistinguishable from other mesenchymal tumors except that leiomyomas are more likely on empirical grounds. The lesions typically range from 2 to 8 cm in diameter but can occasionally be giant masses as large as 20 cm in size.25 Leiomyomas typically appear on computed tomography (CT) as homogeneous soft tissue masses but differentiation from other benign or malignant esophageal tumors is difficult on the basis of the CT findings.26 Although the vast majority of esophageal leiomyomas occur as solitary submucosal masses, barium studies may occasionally reveal multiple submucosal masses or even annular lesions with varying degrees of obstruction.20,21

Esophageal Leiomyomatosis Esophageal leiomyomatosis is a rare, benign condition in which there is neoplastic proliferation of smooth muscle, causing marked circumferential thickening of the esophageal wall, most commonly in the distal esophagus.27-29 It usually occurs as a familial condition with autosomaldominant inheritance and is sometimes associated with widespread visceral leiomyomatosis.29 This condition is found predominantly in children or adolescents who present with long-standing dysphagia that gradually progresses over a period of years.29 Depending on the extent of the lesion, an esophagectomy or esophagogastrectomy is almost always curative.27,29

4 Figure 8. Esophageal leiomyomatosis. (A) Doublecontrast esophagram shows smooth, tapered narrowing of the distal esophagus (black arrows), resembling the appearance of primary achalasia. However, the narrowed segment is longer than that typically seen in achalasia. Also note a soft tissue mass (white arrow) in the gas-filled fundus as a result of bulging of this thickened muscle into the proximal stomach. (B) CT scan shows a mass of relatively low soft tissue attenuation (large arrow) near the gastroesophageal junction, with a slit-like collection of contrast material (small arrow) in the compressed esophageal lumen. (C) More caudal CT scan shows this thickened mass of muscle bulging into the gastric fundus (arrows) on both sides of the cardia. (A-C reproduced with permission).29

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Radiographic Findings Esophageal leiomyomatosis may be manifested on barium studies by smooth, tapered narrowing of the distal esophagus with markedly decreased or absent esophageal peristalsis, mimicking the appearance of primary achalasia (Fig 8A).29 However, the narrowed segment tends to be longer than that in achalasia, and leiomyomatosis is sometimes associated with relatively symmetric paracardiac defects in the gastric fundus as a result of bulging of this thickened mass of muscle into the proximal stomach (see Fig 8A).29 CT may reveal marked circumferential thickening of the distal esophageal wall, resembling the findings of secondary achalasia caused by metastatic tumor at the gastroesophageal junction (Fig 8B and C).29,30 However, esophageal leiomyomatosis usually occurs in children or adolescents with long-standing dysphagia, whereas secondary achalasia occurs in older individuals with recent onset of dysphagia and weight loss.31 Thus, despite its rarity, esophageal leiomyomatosis can sometimes be suspected on the basis of the clinical and radiographic findings.

Fibrovascular Polyp Fibrovascular polyps are rare, benign mesenchymal tumors characterized by the development of pedunculated intraluminal masses that can grow to enormous sizes in the esophagus. These lesions consist of varying amounts of fibrovascular and adipose tissue covered by normal squamous epithelium.32 Depending on the predominant histologic components, these tumors have variously been called hamartomas, fibromas, lipomas, and fibrolipomas.33 More recently, however, the lesions have all been classified together as fibrovascular polyps, a term recommended by the World Health Organization’s international histologic classification of tumors.34 Fibrovascular polyps almost always arise in the cervical esophagus near the level of the cricopharyngeus.32,33 The lesions gradually elongate over a period of years because they are dragged inferiorly by esophageal peristalsis until the inferior tip has reached the middle or even distal third of the esophagus, occasionally prolapsing through the cardia into the gastric fundus.33 Regardless of the size of the polyp, the proximal end is usually attached to the cervical esophagus by a pseudo-pedicle.

Figure 9. Fibrovascular polyp. (A) Double-contrast esophagram shows a smooth, expansile, sausageshaped mass in the upper third of the thoracic esophagus. This lesion has the classic features of a fibrovascular polyp on barium studies. (B) CT scan shows an expansile intraluminal mass (arrow) in the upper third of the thoracic esophagus. Note a peripheral rim of contrast material surrounding the polyp, confirming its intraluminal location. Also note the predominant fat density of the lesion at this level. (A and B reproduced with permission).35

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Fibrovascular polyps most commonly occur in elderly men who present with long-standing dysphagia.35 Some patients may also develop respiratory symptoms such as stridor or wheezing as a result of compression of the adjacent trachea by the polyp.35 Rarely, these individuals may have a spectacular clinical presentation with regurgitation of a fleshy mass into the pharynx or mouth or even asphyxia and sudden death if the regurgitated polyp occludes the larynx.32,33,35,36 Although malignant degeneration of fibrovascular polyps is thought to be extremely rare, removal of these lesions is recommended because of the inexorable progression of symptoms and the theoretical risk of asphyxia and sudden death.22 Radiographic Findings Fibrovascular polyps can sometimes be recognized on frontal chest radiographs by the presence of a smooth, slightly lobulated mass in the right superior mediastinum and on lateral radiographs by a retrotracheal mass displacing the trachea anteriorly.35 Barium studies typically reveal a smooth, expansile, sausage-shaped mass expanding the lumen of the upper or upper and middle thirds of the esophagus (Fig 9A).35,37,38 These lesions therefore have a characteristic appearance on esophagography.

Figure 11. Granular cell tumors. Double-contrast esophagram shows two discrete submucosal masses (arrows) in the middle and distal thirds of the esophagus. This patient had additional granular cell tumors in the stomach. (Reproduced with permission from Levine MS. Benign tumors, in, Levine MS, Radiology of the Esophagus, WB Saunders, Philadelphia, PA, 1989, pp 113-130)

Figure 10. Fibrovascular polyp. CT scan shows an expansile intraluminal mass (arrows) in the upper thoracic esophagus, with a rim of contrast material surrounding the lesion. Note the heterogeneous attenuation of the polyp, with areas of soft tissue density juxtaposed with areas of fat density. The CT findings depend on the amount of fibrovascular and adipose tissue in these lesions. (Reproduced with permission).35

Fibrovascular polyps that contain a considerable amount of adipose tissue classically appear on CT as fat-density lesions expanding the lumen of the esophagus, with a thin rim of contrast surrounding the polyp, confirming its intraluminal location (Fig 9B).35,39-41 However, polyps that contain varying amounts of fibrovascular and adipose tissue may appear as heterogeneous lesions on CT, with areas of fat juxtaposed with areas of soft tissue density (Fig 10), and polyps that contain an abundance of fibrovascular tissue may appear as soft tissue density lesions on CT, with

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a paucity of fat.35 Thus, fibrovascular polyps may be manifested by a spectrum of findings on CT, depending on the predominant histologic components of the lesion.

Granular Cell Tumor Granular cell tumors arise from Schwann cells of the peripheral nervous system. About 7% of granular cell tumors involve the gastrointestinal tract, and one third of these lesions are found in the esophagus.42,43 Histologically, these lesions consist of sheets of polygonal tumor cells containing an eosinophilic-staining granular cytoplasm.44 Granular cell tumors usually appear on esophagography as one or more small, round or ovoid submucosal masses that are often mistaken for leiomyomas on the basis of the radiographic findings (Fig 11).44,45 Most patients with granular cell tumors in the esophagus are asymptomatic and

Figure 13. Duplication cyst. Single-contrast esophagram shows the rare, communicating form of duplication cyst as a tubular, branching outpouching (arrows) from the midesophagus. (Reproduced with permission).22

therefore these lesions are usually detected as incidental findings on barium studies or endoscopy. However, large granular cell tumors that cause dysphagia may require local excision.

Duplication Cyst Figure 12. Duplication cyst. Double-contrast esophagram shows a smooth, submucosal-appearing mass (black arrows) on the right lateral wall of the distal esophagus. Note how the lateral portion of the cyst is visible where it interfaces with the adjacent lung (white arrows). (Reproduced with permission from Levine MS. Benign tumors, in, Levine MS, Radiology of the Esophagus, WB Saunders, Philadelphia, PA, 1989, pp 113-130)

Although duplication cysts are not true neoplasms, they may also appear on barium studies as submucosal masses. Esophageal duplication cysts comprise about 20% of all duplication cysts in the gastrointestinal tract.46 These cysts represent developmental anomalies in which large nests of cells are sequestered from the primitive foregut. Duplication cysts contain multiple layers

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of the bowel wall, including a mucosa, submucosa, and muscularis propria and are lined by a ciliated columnar epithelium.47 Affected individuals are usually asymptomatic, but symptoms may occasionally be caused by bleeding or infection of the cyst.48,49 Although most duplication cysts are noncommunicating, tubular duplications may occasionally communicate directly with the esophageal lumen. Radiographic Findings Duplications cysts tend to be located in the right lower mediastinum. As a result, they can sometimes be recognized on frontal chest radiographs by the presence of a mediastinal mass in this location.22 The cysts typically appear on barium studies as smooth submucosal masses indistinguishable from other more common mesenchymal lesions, such as leiomyomas (Fig 12).22 These fluid-filled cysts usually have characteristic findings on cross-sectional imaging studies, appearing as low-attenuation structures on CT and as high-signal intensity structures on T2-weighted MR images.50,51 When duplication cysts do communicate with the esophageal lumen, they may occasionally be recognized as tubular, branching outpouchings from the esophagus that fill with barium (Fig 13).22

Other Tumors Other rare, benign tumors of the esophagus include lipomas, hemangiomas, hamartomas, fibromas, neurofibromas, and myxofibromas.22 These lesions usually appear on barium studies as discrete intramural masses indistinguishable from leiomyomas. As a result, endoscopic biopsy specimens are required for a definitive diagnosis.

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5. Sandvik AK, Aase S, Kveberg KH, et al: Papillomatosis of the esophagus. J Clin Gastroenterol 22:35-37, 1996 6. Montesi A, Alessandro P, Graziani L, et al: Small benign tumors of the esophagus: radiological diagnosis with double-contrast examinations. Gastrointest Radiol 8:207212, 1983 7. Walker JH: Giant papilloma of the thoracic esophagus. AJR 131:519-520, 1978 8. McDonald GB, Brand DL, Thorning DR: Multiple adenomatous neoplasms arising in columnar-lined (Barrett’s) esophagus. Gastroenterology 72:1317-1321, 1977 9. Levine MS, Caroline D, Thompson JJ, et al: Adenocarcinoma of the esophagus: relationship to Barrett mucosa. Radiology 150:305-309, 1984 10. Bleshman MH, Banner MP, Johnson RC, et al: The inflammatory esophagogastric polyp and fold. Radiology 128:589-593, 1978 11. Staples DC, Knodell RG, Johnson LF: Inflammatory pseudotumor of the esophagus. Gastrointest Endosc 24: 175-176, 1978 12. Styles RA, Gibb SP, Tarshis A, et al: Esophagogastric polyps: Radiographic and endoscopic findings. Radiology 154:307-311, 1985 13. Rywlin AM, Ortega R: Glycogenic acanthosis of the esophagus. Arch Pathol 90:439-443, 1970 14. Ghahremani GG, Rushovich AM: Glycogenic acanthosis of the esophagus: Radiographic and pathologic features. Gastrointest Radiol 9:93-98, 1984 15. Rose D, Furth EE, Rubesin SE: Glycogenic acanthosis. AJR 164:96, 1995 16. Glick SN, Teplick SK, Goldstein J, et al: Glycogenic acanthosis of the esophagus. AJR 139:683-688, 1982 17. Berliner L, Redmond P, Horowitz L, et al: Glycogen plaques (glycogenic acanthosis) of the esophagus. Radiology 141:607-610, 1981 18. Levine MS, Macones AJ, Laufer I: Candida esophagitis: Accuracy of radiographic diagnosis. Radiology 154:581587, 1985 19. Goldstein HM, Zornoza J, Hopens T: Intrinsic diseases of the adult esophagus: Benign and malignant tumors. Semin Roentgenol 16:183-197, 1981 20. Godard JE, McCranie D: Multiple leiomyomas of the esophagus. AJR 117:259-262, 1973 21. Shaffer HA: Multiple leiomyomas of the esophagus. Radiology 118:29-34, 1976 22. Levine MS: Benign tumors of the esophagus, in Gore RM, Levine MS (eds), Textbook of Gastrointestinal Radiology (ed 2), Philadelphia, PA, Saunders, 2000, pp 387-402 23. Griff LC, Cooper J: Leiomyoma of the esophagus presenting as a mediastinal mass. AJR 101: 472-481, 1967 24. Gutman E: Posterior mediastinal calcification due to esophageal leiomyoma. Gastroenterology 63:665-666, 1972 25. Tsuzuki T, Kakegawa T, Arimori M, et al: Giant leiomyoma of the esophagus and cardia weighing more than 1,000 grams. Chest 60:396-399, 1971 26. Megibow AJ, Balthazar EJ, Hulnick DH, et al: CT evaluation of gastrointestinal leiomyomas and leiomyosarcomas. AJR 144:727-731, 1985 27. Fernandes JP, Mascarenhas MJ, daCosta JC, et al: Diffuse leiomyomatosis of the esophagus. Am J Dig Dis 20:684690, 1975

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28. Kabuto T, Taniguchi K, Iwanaga T, et al: Diffuse leiomyomatosis of the esophagus. Dig Dis Sci 25:388-391, 1980 29. Levine MS, Buck JL, Pantongrag-Brown L, et al: Esophageal leiomyomatosis. Radiology 199:533-536, 1996 30. Rabushka LS, Fishman EK, Kuhlman JE, et al: Diffuse esophageal leiomyomatosis in a patient with Alport syndrome: CT demonstration. Radiology 179:176-178, 1991 31. Tucker HJ, Snape WJ, Cohen SC: Achalasia secondary to carcinoma: Manometric and clinical features. Ann Intern Med 89: 315-318, 1978 32. Avezzano EA, Fleischer DE, Merida MA, et al: Giant fibrovascular polyps of the esophagus. Am J Gastroenterol 85:299-302, 1990 33. Patel J, Kieffer RW, Martin M, et al: Giant fibrovascular polyp of the esophagus. Gastroenterology 87:953-956, 1984 34. Watanabe H, Jass JR, Sobin LH: World Health Organization: Histological Typing of Oesophageal and Gastric Tumors (ed 2), Berlin, Springer-Verlag, 1990 35. Levine MS, Buck JL, Pantongrag-Brown L, et al: Fibrovascular polyps of the esophagus: Clinical, radiographic, and pathologic findings in 16 patients. AJR 166:781-787, 1996 36. Cochet B, Hohl P, Sans M, et al: Asphyxia caused by laryngeal impaction of an esophageal polyp. Arch Otolaryngol 106:176-178, 1980 37. Carter MM, Kulkarni MV: Giant fibrovascular polyp of the esophagus. Gastrointest Radiol 9:301-303, 1984 38. Lewis BS, Waye JD, Khilnani MT, et al: Fibrovascular polyp of the esophagus. Mt Sinai J Med 55:324-325, 1988 39. Walters NA, Coral A: Fibrovascular polyp of the oesophagus: The appearances on computed tomography. Br J Radiol 61:641-643, 1988

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40. Whitman GJ, Borkowski GP: Giant fibrovascular polyp of the esophagus: CT and MR findings. AJR 152:518-520, 1989 41. LeBlanc J, Carrier G, Ferland S, et al: Fibrovascular polyp of the esophagus with computed tomographic and pathologic correlation. Can Assoc Radiol J 41:87-89, 1990 42. Lack EE, Worsham GF, Callihan MD, et al: Granular cell tumor: A clinicopathologic study of 110 patients. J Surg Oncol 13:301-306, 1980 43. Johnston J, Helwig EB: Granular cell tumors of the gastrointestinal tract and perianal region: A study of 74 cases. Dig Dis Sci 26:807-816, 1981 44. Rubesin SE, Herlinger H, Sigal H: Granular cell tumors of the esophagus. Gastrointest Radiol 10:11-15, 1985 45. Gershwind ME, Chiat H, Addei KA, et al: Granular cell tumors of the esophagus. Gastrointest Radiol 2:327-330, 1978 46. Macpherson RI: Gastrointestinal tract duplications: clinical, pathologic, etiologic, and radiologic considerations. RadioGraphics 13:1063-1080, 1993 47. Vithespongse P, Blank S: Ciliated epithelial esophageal cyst. Am J Gastroenterol 56:436-440, 1971 48. Gatzinsky P, Fasth S, Hansson G: Intramural oesophageal cyst with massive mediastinal bleeding. Scand J Thorac Cardiovasc Surg 12: 143-145, 1978 49. Whitaker JA, Deffenbaugh LD, Cooke AR: Esophageal duplication cyst. Am J Gastroenterol 73:329-332, 1980 50. Bondestam S, Salo JA, Salonen OLM, et al: Imaging of congenital esophageal cysts in adults. Gastrointest Radiol 15:279-281, 1990 51. Rafal RB, Markisz JA: Magnetic resonance imaging of an esophageal duplication cyst. Am J Gastroenterol 86:18091811, 1991