Received May 21 , 1990; accepted after revision July 2, 1990. I All authors: Department of Radiology, The Medical College of Wisconsin, Milwaukee, WI 53226. Address reprint requests to A. J. Taylor, Department of Radiology, Froedtert Memorial Lutheran Hospital, 9200 W. Wisconsin Ave., Milwaukee, WI 53226. AJR 155:1205-1210, December 1990 0361 -803x/90/1 556-1 205 C American Roentgen Ray Society 1205 Pictorial Essay Gastrointestinal Lipomas: A Radiologic and Pathologic Review Andrew J. Taylor,1 Edward T. Stewart, and Wylie J. Dodds Lipomas of the gastrointestinal tract are an infrequent finding on radiologic examination; however, they occur often enough to warrant consideration in the differential diagnosis of mass lesions of the gut In many instances, their morphologic characteristics allow the specific diagnosis of a lipoma. In this report, we review gastrointestinal lipomas with an emphasis on their radiologic and pathologic correlation. General Considerations Lipomas of the gastrointestinal tract are uncommon, slow growing, fatty tumors that can occur anywhere along the gut. Although generally single, they may be multiple. Peak occur- rence is in the fifth to seventh decade of life, with a slight female preponderance. The tumor itself is composed of well- differentiated adipose tissue surrounded by a fibrous capsule. The cut surface is yellow and lobulated with a gross appear- ance of subcutaneous fat (Fig. 1 D). Approximately 90% to 95% of lipomas are located in the submucosa; the remaining 5% to 1 0% are subserosal [1]. Because of its usual position immediately superficial to the muscularis propria, underlying muscular contractions tend to draw the tumor into the bowel lumen, forming an intraluminal polyp on a pseudopedicle (Figs. 2A, 3B, 4A). Lipomas usually are found incidentally during an examina- tion done for another reason (Fig. 5). The size and location of the lipoma and the mobility afforded by the pseudopedicle, when present, account for the clinical signs and symptoms produced. Lesions larger than 2 cm may produce abdominal pain, intussusception, diarrhea, constipation, or gastrointes- tinal blood loss [1 , 2]. The gastrointestinal blood loss is usually chronic and can cause anemia [1]. Acute hemorrhage, how- ever, can occur and usually is caused by ulceration of the overlying mucosa (Figs. 6C, 3E) or possibly intussusception (Figs. 1B, 3A). Diagnosis Endoscopy Endoscopy and radiology play a major role in the diagnosis of lipomas. Endoscopy relies on the gross appearance of the mass to suggest the correct diagnosis. A smooth-surfaced mass that may vary from red-orange to yellow suggests the diagnosis of lipoma (Fig. 7C). Various maneuvers are used to confirm the diagnosis: (1) The “tenting” sign consists in grasp- ing the mucosa with forceps and pulling or “tenting” it away from the underlying mass. (2) The “cushion” sign reflects the spongy nature of the mass when indented with a closed forceps. (3) The “naked fat” sign is produced when fat pro- trudes from the mass after multiple biopsies remove the overlying mucosa. A lipoma occasionally can be lobulated or have an apical ulceration (Fig. 3D). At times, ulceration can be fairly extensive, (Fig. 1 C), leading to the false impression of a more aggressive lesion. Downloaded from www.ajronline.org by 171.243.0.161 on 03/11/23 from IP address 171.243.0.161. Copyright ARRS. For personal use only; all rights reserved
Welcome message from author
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
Gastrointestinal lipomas: a radiologic and pathologic review.Received May 21 , 1990; accepted after revision July 2, 1990.
I All authors: Department of Radiology, The Medical College of Wisconsin, Milwaukee, WI 53226. Address reprint requests to A. J. Taylor, Department of Radiology, Froedtert Memorial Lutheran Hospital, 9200 W. Wisconsin Ave., Milwaukee, WI 53226.
AJR 155:1205-1210, December 1990 0361 -803x/90/1 556-1 205 C American Roentgen Ray Society
1205
Gastrointestinal Lipomas: A Radiologic and Pathologic Review Andrew J. Taylor,1 Edward T. Stewart, and Wylie J. Dodds
Lipomas of the gastrointestinal tract are an infrequent finding on radiologic examination; however, they occur often enough to warrant consideration in the differential diagnosis of mass lesions of the gut In many instances, their morphologic characteristics allow the specific diagnosis of a lipoma. In this report, we review gastrointestinal lipomas with an emphasis on their radiologic and pathologic correlation.
General Considerations
Lipomas of the gastrointestinal tract are uncommon, slow growing, fatty tumors that can occur anywhere along the gut. Although generally single, they may be multiple. Peak occur- rence is in the fifth to seventh decade of life, with a slight female preponderance. The tumor itself is composed of well- differentiated adipose tissue surrounded by a fibrous capsule. The cut surface is yellow and lobulated with a gross appear- ance of subcutaneous fat (Fig. 1 D).
Approximately 90% to 95% of lipomas are located in the
submucosa; the remaining 5% to 1 0% are subserosal [1]. Because of its usual position immediately superficial to the muscularis propria, underlying muscular contractions tend to
draw the tumor into the bowel lumen, forming an intraluminal polyp on a pseudopedicle (Figs. 2A, 3B, 4A).
Lipomas usually are found incidentally during an examina- tion done for another reason (Fig. 5). The size and location of the lipoma and the mobility afforded by the pseudopedicle, when present, account for the clinical signs and symptoms
produced. Lesions larger than 2 cm may produce abdominal pain, intussusception, diarrhea, constipation, or gastrointes- tinal blood loss [1 , 2]. The gastrointestinal blood loss is usually chronic and can cause anemia [1]. Acute hemorrhage, how- ever, can occur and usually is caused by ulceration of the overlying mucosa (Figs. 6C, 3E) or possibly intussusception (Figs. 1B, 3A).
Diagnosis
Endoscopy
Endoscopy and radiology play a major role in the diagnosis of lipomas. Endoscopy relies on the gross appearance of the mass to suggest the correct diagnosis. A smooth-surfaced mass that may vary from red-orange to yellow suggests the diagnosis of lipoma (Fig. 7C). Various maneuvers are used to confirm the diagnosis: (1) The “tenting” sign consists in grasp- ing the mucosa with forceps and pulling or “tenting” it away from the underlying mass. (2) The “cushion” sign reflects the spongy nature of the mass when indented with a closed forceps. (3) The “naked fat” sign is produced when fat pro- trudes from the mass after multiple biopsies remove the overlying mucosa. A lipoma occasionally can be lobulated or have an apical ulceration (Fig. 3D). At times, ulceration can be fairly extensive, (Fig. 1 C), leading to the false impression of a more aggressive lesion.D
ow nl
oa de
d fr
om w
w w
.a jr
on lin
e. or
g by
1 71
.2 43
.0 .1
61 o
n 03
/1 1/
23 f
ro m
I P
ad dr
es s
17 1.
24 3.
0. 16
1. C
op yr
ig ht
A R
R S.
F or
p er
so na
1206 TAYLOR ET AL. AJR:155, December 1990
Fig. 1.-Small-bowel lipoma. A 39-year-old man had a 1-week history of increasing, inter- mittent, crampy epigastric pain. He had been followed up for 5 years because of a low hema- tocrit and guaiac-positive stools, thought to be a resuft of “runner’s anemia.”
A, On small-bowel series, a 3 x 4 cm polypoid mass was seen just distal to ligament of Treitz. At fiuoroscopy, there was intermittent intussus- ception. Note subtle Irregularity of mass, partic- ularly at its apex (arrows).
B, At surgery, intussusception of jejunum was found. Point of intussusception (curved arrow) is seen between dilated jejunum proximally (open arrow) and normal caliber of jejunum just distally (straight solid arrow).
C, Resected specimen shows marked irregu- larity of mucosal surface due to healing of over- lying ulcerated and necrotic mucosa.
D, Bivalved specimen shows fatty internal ar- chitecture of a lipoma.
Fig. 2.-Esophageal lipoma. A 50-year-old woman had intermittent dysphagia. (Courtesy of J. Lammers, Brookfield, WI).
A, Anteropostenor view from an esophago- gram shows a large, smooth, mobile, peduncu- lated polyp in upper esophagus.
B, Subsequent CT scan shows homogeneous internal architecture of mass (arrow) with an attenuation similar to that of subcutaneous fat. These findings are diagnostic of a lipoma, which subsequently was proved by surgery. Lipoma had its origin just distal to cricoid cartilage.
Increased sophistication of radiologic studies now enables lipomas larger than 2 cm to be diagnosed with a high degree of accuracy [2]. The classic findings of a sharply marginated, smooth, ovoid or spherical mass with compressibility on fluoroscopic examination are supportive evidence of a lipoma (Figs. 7A and 7B). Other findings seen during studies follow directly from the gross appearance of lipoma wherein lobula-
tion and ulceration can be seen (Fig. 6A). However, with the use of a positive-contrast examination, it is only rarely possible to discern the relative low density of a mass when outlined by barium (Fig. 5). The imaginative water enema, developed to circumvent this problem (Fig. 8), has fallen from favor with the advent of newer imaging techniques.
CT, in the properly prepared patient, is able to take advan- tage of the fat content, thereby identifying a mass as a lipoma. CT examination is now an appropriate first step for a definitive
D ow
nl oa
de d
fr om
w w
w .a
jr on
lin e.
or g
by 1
71 .2
43 .0
.1 61
o n
03 /1
1/ 23
f ro
m I
P ad
dr es
s 17
1. 24
3. 0.
16 1.
C op
yr ig
ht A
R R
S. F
or p
er so
AJR:155, December1990 GASTROINTESTINAL LIPOMAS 1207
Fig. 3.-Colonic lipoma. A 67-year-old woman with 2-year history of vague pain in right lower quadrant had a recent change in bowel habits. She was having three to four loose stools each day and associated crampy pain and blood.
A, Single-contrast barium enema shows a colonic intussusception with tip of intussusceptum (arrow) at tip of distal transverse colon. B, On reduction of intussusception during barium enema, a large mass with a wide stalk is seen originating from ileocecaI valve. C, CT scan shows mass (straight arrows) intussuscepted to distal transverse colon once again. Low attenuation value of mass is compatible with fat.
Note central linear strand of higher attenuation material at base of mass (curved arrow). D, At colonoscopy, a large pinkish-orange mass capped with an ulcer (arrow) is seen. E, Surgical specimen shows a 6 x 5 x 4 cm mass with a broad-based pseudostalk and a large superficial ulcer at apex of mass (arrow). Note discolored
fat protruding through ulcer.
Fig. 4.-Lipoma of sigmoid colon. A 36-year- old woman had a 2-day history of crampy pain in left lower quadrant. She recentiy had passed bright red blood per rectum.
A, Anteroposterior view of sigmold colon from a single-contrast barium enema shows an oval, well-circumscribed mass with a short, thick ped- ide.
B, Surgical specimen shows a lipoma with superficial ulceration at apex (arrow).
D ow
nl oa
de d
fr om
w w
w .a
jr on
lin e.
or g
by 1
71 .2
43 .0
.1 61
o n
03 /1
1/ 23
f ro
m I
P ad
dr es
s 17
1. 24
3. 0.
16 1.
C op
yr ig
ht A
R R
S. F
or p
er so
1208 TAYLOR ET AL. AJR:155, December1990
Fig. 5.-Small incidental colonic lipoma. A 27- year-old man had bright red blood per rectum.
A, Anteroposterior coned-down view from a double-contrast barium enema shows sessile mass (arrows) in distal transverse colon. Mass was 1.0 x 2.5 cm, smooth and oval, with a very low density.
B, A lateral view of same bowel segment shows mass in profile (arrows). Better visualized in this view is low density of mass, which is compatible with fat. Patient had endoscopy to locate source of bleeding: an anal fissure. Li- poma was not seen.
Fig. 6.-Gastric lipoma. An 83-year-old woman had a 2-week history of melena and decreasing hematocrit, necessitating transfusion of 5 unIts of blood.
A, Upper gastrointestinal examination shows a relatively smooth gastric mass (straight solid arrows) with an ulcer (curved arrow), and a lobulation off side of mass (open arrows).
B, CT scan shows a mass (straight arrows) of fatty internal architecture, -50 HU, with a curvilinear density (curved arrow) extending into fat from base of mass.
C, At surgery, mass (solid arrows) shows an ulcer (open arrow).
diagnosis of a lipoma. The finding of a homogeneous mass with Hounsfield units between -80 and -1 20 is nearly pa- thognomonic for a lipoma (Fig. 2B). Heiken et al. [2] reported
that lipomas seen on CT did not have nonfatty elements. However, in two of our cases (Figs. 3, 6), linear strands of soft-tissue attenuation were shown at the base of the lipomas (Figs. 3C, 6B). Both of these tumors had an associated ulcer. On pathologic examination, these strands seen on CT corre- lated with prominent fibrovascular septa, which are normally microscopic. These septa presumably enlarged from drainage of the inflammation associated with an ulcer. We therefore suggest that the presence of basilar strands of nonfatty elements in an otherwise uniform fatty tumefaction would qualify the lesion as a benign lipoma, probably containing an ulcer. This pattern should not be mistaken for a liposarcoma, which is extremely rare in the alimentary tract [2].
Location Within Alimentary Tract
Pharynx and Esophagus
Lipomas may develop in the pharynx or in the esophagus, although these are the least common areas of involvement in the alimentary tract. Pharyngeal involvement is usually in the hypopharynx. The Iipoma commonly takes its origin from structures lying between and including the aryepiglottic folds to the pyriform sinuses [3]. Of the pedunculated pharyngeal polyps, the simple lipoma is relatively uncommon compared with the more frequent fibrolipoma [4]. The potential mobility of a hypopharyngeal lipoma and its location at the bifurcation of the aerodigestive tract accounts for the signs and symp- toms of dysphagia, fullness in the throat, change in voice, sudden episodic attacks of dyspnea, and sleep apnea (Fig. 7)
D ow
nl oa
de d
fr om
w w
w .a
jr on
lin e.
or g
by 1
71 .2
43 .0
.1 61
o n
03 /1
1/ 23
f ro
m I
P ad
dr es
s 17
1. 24
3. 0.
16 1.
C op
yr ig
ht A
R R
S. F
or p
er so
AJR:155, December1990 GASTROINTESTINAL LIPOMAS 1209
Fig. 7.-Llpoma of hypopharynx. A 66-year- old man had an 18-month history of dysphagia and episodic paroxysms of cough.
A, Oblique view from an esophagogram shows a smooth, pedunculated 7-cm mass that appears to emanate from hypopharynx. (Re- printed with permission from Olson et al (4].)
B, Immediately after a swallow, mass elon- gates. In this case, intrinsic peristalsis of viscus shows complIance of mass. This phenomenon is referred to as “autopalpation.” (Reprinted with permission from Olson et aL (4].)
C, Image from pharyngeal endoscopy shows a smooth pinkish-orange mass (straight solid arrows) In left pyriform sinus. (Open arrow = free edge of epiglottis, curved arrow = base of tongue).
0, Gross specimen shows mass has a pseu- dostalk.
Fig. 8.-Lipoma shown by water enema. A, Initial single-contrast barium enema shows
a smooth mass (arrows) opposite ileocecal valve.
B, Subsequent enema with water shows mass (arrows) Is lucent compared with surrounding water. This finding is compatible with a lipoma, which subsequently was proved at surgery. (Bar- ium-fllIed appendix projects over part of lipoma).
[4]. In some cases, the polyp may prolapse into the esopha- gus (Figs. 7A, 7B) and be mistaken for a mass of esophageal origin.
Of benign esophageal tumors, the sessile leiomyoma is
most frequent; the fibrovascular polyp is the most common pedunculated esophageal polyp [4]. The lipoma is next in frequency, generally arising from the upper one third of the esophagus near the level of the cricoid cartilage (Fig. 2) [4].
D ow
nl oa
de d
fr om
w w
w .a
jr on
lin e.
or g
by 1
71 .2
43 .0
.1 61
o n
03 /1
1/ 23
f ro
m I
P ad
dr es
s 17
1. 24
3. 0.
16 1.
C op
yr ig
ht A
R R
S. F
or p
er so
1210 TAYLOR ET AL. AJR:155, December 1990
Fig. 9.-Multiple gastric and duodenal lipo- mas. A 50-year-old woman had a 4-month history of epigastric pain, with recent onset of intermit- tent vomiting. Single anteroposterior view from an upper gastrointestinal series shows multiple smooth masses along greater curvature of stom- ach (long arrows). Mass lesions (short arrows) continue into duodenum. At surgery, mass le- sions were found to be lipomas. (Reprinted with permission from Deeths et al [6].)
Fig. 10.-Multiple colonic lipomas. An oblique view from single-contrast barium enema shows two smooth, well-circumscribed masses (ar- rows) at splenic flexure. At surgery, these proved to be lipomas.
Stomach
Gastric lipomas are a rare lesion accounting for only 5% of alimentary tract lipomas and for only 3% of all benign gastric masses [5]. Most gastric lipomas are located in the antrum; the remainder are spread throughout the body and fundus (Fig. 6). The usual antral location accounts for a high fre- quency of prolapse into the pylorus. Because of the lipoma’s supple nature, however, complete obstruction of the gastric outlet seldom occurs. As in other segments ofthe gut, lipomas are usually single but may be multiple (Fig. 9).
Small Bowel
The small bowel ranks as the second most common loca- tion for lipomas of the gut. About 20-25% of lipomas occur here [7], most frequently in the ileum. Lipomas are found less frequently in the jejunum (Fig. 1) and duodenum (Fig. 9) [7]. The lipoma is the second most common benign tumor of the small bowel; the first is leiomyoma [7].
Colon
The colon is the most frequently involved segment of the bowel, accounting for 65-75% of lipomas [7]. In fact, lipomas are the second (albeit a distant second) most common benign tumor of the colon, after the adenomatous polyp [1]. Lipomas are found most commonly in the cecum (Fig. 6) and the right
side of the colon, and next most commonly in the sigmoid colon (Fig. 4). The true lipoma of the ileocecal valve should not be confused with the more frequent lipomatosis of the valve. In the former case, the fat is encapsulated, causing a well-defined mass emanating from the valve instead of the generalized enlargement seen with diffuse fatty infiltration.
Most colonic lipomas are solitary, but occasionally they may be multiple (Fig. 1 0). A rare condition of colonic lipoma- tosis exists in which innumerable small fatty deposits are present [8].
REFERENCES
1 . Femandez MJ, Davis RP, Nora PF. Gastrointestinal lipomas. Arch Surg 1983:118:1081-1083
2. Heiken JP, Forde KA, Gold RP. Computed tomography as a definitive method for diagnosing gastrointestinal lipomas. Radiology 1982:142: 409-414
3. Som PM, Scherl MP, Rao vM, Biller HF. Rare presentations of ordinary lipomas of the head and neck: a review. AJNR 1986;7:657-664
4. Olson DL, Dodds WJ, Stewart ET, Helm JF, Duncavage JA. Pedunculated pharyngeal lipoma presenting as an esophageal polyp. Dysphagia 1987:2:113-116
5. Chu AG, Clifton JA. Gastric lipoma presenting as peptic ulcer: case report
and review of the literature. Am J Gastroenterol 1983:78:615-618 6. Deeths TM, Madden PN, Dodds WJ. Multiple lipomas of the stomach and
duodenum. Dig Dis Sci 1975:20:771-774 7. Agha FP, Dent TL, Fiddian-Green RG, Braunstein AH, Nostrant U. Bleed-
ing lipomas of the upper gastrointestinal tract: a diagnostic challenge. Am
Surg 1985:51 :279-285 8. Yatto RP. Colonic lipomatosis. Am J Gastroenterol 1982;77:436-437
D ow
nl oa
de d
fr om
w w
w .a
jr on
lin e.
or g
by 1
71 .2
43 .0
.1 61
o n
03 /1
1/ 23
f ro
m I
P ad
dr es
s 17
1. 24
3. 0.
16 1.
C op
yr ig
ht A
R R
S. F
or p
er so
I All authors: Department of Radiology, The Medical College of Wisconsin, Milwaukee, WI 53226. Address reprint requests to A. J. Taylor, Department of Radiology, Froedtert Memorial Lutheran Hospital, 9200 W. Wisconsin Ave., Milwaukee, WI 53226.
AJR 155:1205-1210, December 1990 0361 -803x/90/1 556-1 205 C American Roentgen Ray Society
1205
Gastrointestinal Lipomas: A Radiologic and Pathologic Review Andrew J. Taylor,1 Edward T. Stewart, and Wylie J. Dodds
Lipomas of the gastrointestinal tract are an infrequent finding on radiologic examination; however, they occur often enough to warrant consideration in the differential diagnosis of mass lesions of the gut In many instances, their morphologic characteristics allow the specific diagnosis of a lipoma. In this report, we review gastrointestinal lipomas with an emphasis on their radiologic and pathologic correlation.
General Considerations
Lipomas of the gastrointestinal tract are uncommon, slow growing, fatty tumors that can occur anywhere along the gut. Although generally single, they may be multiple. Peak occur- rence is in the fifth to seventh decade of life, with a slight female preponderance. The tumor itself is composed of well- differentiated adipose tissue surrounded by a fibrous capsule. The cut surface is yellow and lobulated with a gross appear- ance of subcutaneous fat (Fig. 1 D).
Approximately 90% to 95% of lipomas are located in the
submucosa; the remaining 5% to 1 0% are subserosal [1]. Because of its usual position immediately superficial to the muscularis propria, underlying muscular contractions tend to
draw the tumor into the bowel lumen, forming an intraluminal polyp on a pseudopedicle (Figs. 2A, 3B, 4A).
Lipomas usually are found incidentally during an examina- tion done for another reason (Fig. 5). The size and location of the lipoma and the mobility afforded by the pseudopedicle, when present, account for the clinical signs and symptoms
produced. Lesions larger than 2 cm may produce abdominal pain, intussusception, diarrhea, constipation, or gastrointes- tinal blood loss [1 , 2]. The gastrointestinal blood loss is usually chronic and can cause anemia [1]. Acute hemorrhage, how- ever, can occur and usually is caused by ulceration of the overlying mucosa (Figs. 6C, 3E) or possibly intussusception (Figs. 1B, 3A).
Diagnosis
Endoscopy
Endoscopy and radiology play a major role in the diagnosis of lipomas. Endoscopy relies on the gross appearance of the mass to suggest the correct diagnosis. A smooth-surfaced mass that may vary from red-orange to yellow suggests the diagnosis of lipoma (Fig. 7C). Various maneuvers are used to confirm the diagnosis: (1) The “tenting” sign consists in grasp- ing the mucosa with forceps and pulling or “tenting” it away from the underlying mass. (2) The “cushion” sign reflects the spongy nature of the mass when indented with a closed forceps. (3) The “naked fat” sign is produced when fat pro- trudes from the mass after multiple biopsies remove the overlying mucosa. A lipoma occasionally can be lobulated or have an apical ulceration (Fig. 3D). At times, ulceration can be fairly extensive, (Fig. 1 C), leading to the false impression of a more aggressive lesion.D
ow nl
oa de
d fr
om w
w w
.a jr
on lin
e. or
g by
1 71
.2 43
.0 .1
61 o
n 03
/1 1/
23 f
ro m
I P
ad dr
es s
17 1.
24 3.
0. 16
1. C
op yr
ig ht
A R
R S.
F or
p er
so na
1206 TAYLOR ET AL. AJR:155, December 1990
Fig. 1.-Small-bowel lipoma. A 39-year-old man had a 1-week history of increasing, inter- mittent, crampy epigastric pain. He had been followed up for 5 years because of a low hema- tocrit and guaiac-positive stools, thought to be a resuft of “runner’s anemia.”
A, On small-bowel series, a 3 x 4 cm polypoid mass was seen just distal to ligament of Treitz. At fiuoroscopy, there was intermittent intussus- ception. Note subtle Irregularity of mass, partic- ularly at its apex (arrows).
B, At surgery, intussusception of jejunum was found. Point of intussusception (curved arrow) is seen between dilated jejunum proximally (open arrow) and normal caliber of jejunum just distally (straight solid arrow).
C, Resected specimen shows marked irregu- larity of mucosal surface due to healing of over- lying ulcerated and necrotic mucosa.
D, Bivalved specimen shows fatty internal ar- chitecture of a lipoma.
Fig. 2.-Esophageal lipoma. A 50-year-old woman had intermittent dysphagia. (Courtesy of J. Lammers, Brookfield, WI).
A, Anteropostenor view from an esophago- gram shows a large, smooth, mobile, peduncu- lated polyp in upper esophagus.
B, Subsequent CT scan shows homogeneous internal architecture of mass (arrow) with an attenuation similar to that of subcutaneous fat. These findings are diagnostic of a lipoma, which subsequently was proved by surgery. Lipoma had its origin just distal to cricoid cartilage.
Increased sophistication of radiologic studies now enables lipomas larger than 2 cm to be diagnosed with a high degree of accuracy [2]. The classic findings of a sharply marginated, smooth, ovoid or spherical mass with compressibility on fluoroscopic examination are supportive evidence of a lipoma (Figs. 7A and 7B). Other findings seen during studies follow directly from the gross appearance of lipoma wherein lobula-
tion and ulceration can be seen (Fig. 6A). However, with the use of a positive-contrast examination, it is only rarely possible to discern the relative low density of a mass when outlined by barium (Fig. 5). The imaginative water enema, developed to circumvent this problem (Fig. 8), has fallen from favor with the advent of newer imaging techniques.
CT, in the properly prepared patient, is able to take advan- tage of the fat content, thereby identifying a mass as a lipoma. CT examination is now an appropriate first step for a definitive
D ow
nl oa
de d
fr om
w w
w .a
jr on
lin e.
or g
by 1
71 .2
43 .0
.1 61
o n
03 /1
1/ 23
f ro
m I
P ad
dr es
s 17
1. 24
3. 0.
16 1.
C op
yr ig
ht A
R R
S. F
or p
er so
AJR:155, December1990 GASTROINTESTINAL LIPOMAS 1207
Fig. 3.-Colonic lipoma. A 67-year-old woman with 2-year history of vague pain in right lower quadrant had a recent change in bowel habits. She was having three to four loose stools each day and associated crampy pain and blood.
A, Single-contrast barium enema shows a colonic intussusception with tip of intussusceptum (arrow) at tip of distal transverse colon. B, On reduction of intussusception during barium enema, a large mass with a wide stalk is seen originating from ileocecaI valve. C, CT scan shows mass (straight arrows) intussuscepted to distal transverse colon once again. Low attenuation value of mass is compatible with fat.
Note central linear strand of higher attenuation material at base of mass (curved arrow). D, At colonoscopy, a large pinkish-orange mass capped with an ulcer (arrow) is seen. E, Surgical specimen shows a 6 x 5 x 4 cm mass with a broad-based pseudostalk and a large superficial ulcer at apex of mass (arrow). Note discolored
fat protruding through ulcer.
Fig. 4.-Lipoma of sigmoid colon. A 36-year- old woman had a 2-day history of crampy pain in left lower quadrant. She recentiy had passed bright red blood per rectum.
A, Anteroposterior view of sigmold colon from a single-contrast barium enema shows an oval, well-circumscribed mass with a short, thick ped- ide.
B, Surgical specimen shows a lipoma with superficial ulceration at apex (arrow).
D ow
nl oa
de d
fr om
w w
w .a
jr on
lin e.
or g
by 1
71 .2
43 .0
.1 61
o n
03 /1
1/ 23
f ro
m I
P ad
dr es
s 17
1. 24
3. 0.
16 1.
C op
yr ig
ht A
R R
S. F
or p
er so
1208 TAYLOR ET AL. AJR:155, December1990
Fig. 5.-Small incidental colonic lipoma. A 27- year-old man had bright red blood per rectum.
A, Anteroposterior coned-down view from a double-contrast barium enema shows sessile mass (arrows) in distal transverse colon. Mass was 1.0 x 2.5 cm, smooth and oval, with a very low density.
B, A lateral view of same bowel segment shows mass in profile (arrows). Better visualized in this view is low density of mass, which is compatible with fat. Patient had endoscopy to locate source of bleeding: an anal fissure. Li- poma was not seen.
Fig. 6.-Gastric lipoma. An 83-year-old woman had a 2-week history of melena and decreasing hematocrit, necessitating transfusion of 5 unIts of blood.
A, Upper gastrointestinal examination shows a relatively smooth gastric mass (straight solid arrows) with an ulcer (curved arrow), and a lobulation off side of mass (open arrows).
B, CT scan shows a mass (straight arrows) of fatty internal architecture, -50 HU, with a curvilinear density (curved arrow) extending into fat from base of mass.
C, At surgery, mass (solid arrows) shows an ulcer (open arrow).
diagnosis of a lipoma. The finding of a homogeneous mass with Hounsfield units between -80 and -1 20 is nearly pa- thognomonic for a lipoma (Fig. 2B). Heiken et al. [2] reported
that lipomas seen on CT did not have nonfatty elements. However, in two of our cases (Figs. 3, 6), linear strands of soft-tissue attenuation were shown at the base of the lipomas (Figs. 3C, 6B). Both of these tumors had an associated ulcer. On pathologic examination, these strands seen on CT corre- lated with prominent fibrovascular septa, which are normally microscopic. These septa presumably enlarged from drainage of the inflammation associated with an ulcer. We therefore suggest that the presence of basilar strands of nonfatty elements in an otherwise uniform fatty tumefaction would qualify the lesion as a benign lipoma, probably containing an ulcer. This pattern should not be mistaken for a liposarcoma, which is extremely rare in the alimentary tract [2].
Location Within Alimentary Tract
Pharynx and Esophagus
Lipomas may develop in the pharynx or in the esophagus, although these are the least common areas of involvement in the alimentary tract. Pharyngeal involvement is usually in the hypopharynx. The Iipoma commonly takes its origin from structures lying between and including the aryepiglottic folds to the pyriform sinuses [3]. Of the pedunculated pharyngeal polyps, the simple lipoma is relatively uncommon compared with the more frequent fibrolipoma [4]. The potential mobility of a hypopharyngeal lipoma and its location at the bifurcation of the aerodigestive tract accounts for the signs and symp- toms of dysphagia, fullness in the throat, change in voice, sudden episodic attacks of dyspnea, and sleep apnea (Fig. 7)
D ow
nl oa
de d
fr om
w w
w .a
jr on
lin e.
or g
by 1
71 .2
43 .0
.1 61
o n
03 /1
1/ 23
f ro
m I
P ad
dr es
s 17
1. 24
3. 0.
16 1.
C op
yr ig
ht A
R R
S. F
or p
er so
AJR:155, December1990 GASTROINTESTINAL LIPOMAS 1209
Fig. 7.-Llpoma of hypopharynx. A 66-year- old man had an 18-month history of dysphagia and episodic paroxysms of cough.
A, Oblique view from an esophagogram shows a smooth, pedunculated 7-cm mass that appears to emanate from hypopharynx. (Re- printed with permission from Olson et al (4].)
B, Immediately after a swallow, mass elon- gates. In this case, intrinsic peristalsis of viscus shows complIance of mass. This phenomenon is referred to as “autopalpation.” (Reprinted with permission from Olson et aL (4].)
C, Image from pharyngeal endoscopy shows a smooth pinkish-orange mass (straight solid arrows) In left pyriform sinus. (Open arrow = free edge of epiglottis, curved arrow = base of tongue).
0, Gross specimen shows mass has a pseu- dostalk.
Fig. 8.-Lipoma shown by water enema. A, Initial single-contrast barium enema shows
a smooth mass (arrows) opposite ileocecal valve.
B, Subsequent enema with water shows mass (arrows) Is lucent compared with surrounding water. This finding is compatible with a lipoma, which subsequently was proved at surgery. (Bar- ium-fllIed appendix projects over part of lipoma).
[4]. In some cases, the polyp may prolapse into the esopha- gus (Figs. 7A, 7B) and be mistaken for a mass of esophageal origin.
Of benign esophageal tumors, the sessile leiomyoma is
most frequent; the fibrovascular polyp is the most common pedunculated esophageal polyp [4]. The lipoma is next in frequency, generally arising from the upper one third of the esophagus near the level of the cricoid cartilage (Fig. 2) [4].
D ow
nl oa
de d
fr om
w w
w .a
jr on
lin e.
or g
by 1
71 .2
43 .0
.1 61
o n
03 /1
1/ 23
f ro
m I
P ad
dr es
s 17
1. 24
3. 0.
16 1.
C op
yr ig
ht A
R R
S. F
or p
er so
1210 TAYLOR ET AL. AJR:155, December 1990
Fig. 9.-Multiple gastric and duodenal lipo- mas. A 50-year-old woman had a 4-month history of epigastric pain, with recent onset of intermit- tent vomiting. Single anteroposterior view from an upper gastrointestinal series shows multiple smooth masses along greater curvature of stom- ach (long arrows). Mass lesions (short arrows) continue into duodenum. At surgery, mass le- sions were found to be lipomas. (Reprinted with permission from Deeths et al [6].)
Fig. 10.-Multiple colonic lipomas. An oblique view from single-contrast barium enema shows two smooth, well-circumscribed masses (ar- rows) at splenic flexure. At surgery, these proved to be lipomas.
Stomach
Gastric lipomas are a rare lesion accounting for only 5% of alimentary tract lipomas and for only 3% of all benign gastric masses [5]. Most gastric lipomas are located in the antrum; the remainder are spread throughout the body and fundus (Fig. 6). The usual antral location accounts for a high fre- quency of prolapse into the pylorus. Because of the lipoma’s supple nature, however, complete obstruction of the gastric outlet seldom occurs. As in other segments ofthe gut, lipomas are usually single but may be multiple (Fig. 9).
Small Bowel
The small bowel ranks as the second most common loca- tion for lipomas of the gut. About 20-25% of lipomas occur here [7], most frequently in the ileum. Lipomas are found less frequently in the jejunum (Fig. 1) and duodenum (Fig. 9) [7]. The lipoma is the second most common benign tumor of the small bowel; the first is leiomyoma [7].
Colon
The colon is the most frequently involved segment of the bowel, accounting for 65-75% of lipomas [7]. In fact, lipomas are the second (albeit a distant second) most common benign tumor of the colon, after the adenomatous polyp [1]. Lipomas are found most commonly in the cecum (Fig. 6) and the right
side of the colon, and next most commonly in the sigmoid colon (Fig. 4). The true lipoma of the ileocecal valve should not be confused with the more frequent lipomatosis of the valve. In the former case, the fat is encapsulated, causing a well-defined mass emanating from the valve instead of the generalized enlargement seen with diffuse fatty infiltration.
Most colonic lipomas are solitary, but occasionally they may be multiple (Fig. 1 0). A rare condition of colonic lipoma- tosis exists in which innumerable small fatty deposits are present [8].
REFERENCES
1 . Femandez MJ, Davis RP, Nora PF. Gastrointestinal lipomas. Arch Surg 1983:118:1081-1083
2. Heiken JP, Forde KA, Gold RP. Computed tomography as a definitive method for diagnosing gastrointestinal lipomas. Radiology 1982:142: 409-414
3. Som PM, Scherl MP, Rao vM, Biller HF. Rare presentations of ordinary lipomas of the head and neck: a review. AJNR 1986;7:657-664
4. Olson DL, Dodds WJ, Stewart ET, Helm JF, Duncavage JA. Pedunculated pharyngeal lipoma presenting as an esophageal polyp. Dysphagia 1987:2:113-116
5. Chu AG, Clifton JA. Gastric lipoma presenting as peptic ulcer: case report
and review of the literature. Am J Gastroenterol 1983:78:615-618 6. Deeths TM, Madden PN, Dodds WJ. Multiple lipomas of the stomach and
duodenum. Dig Dis Sci 1975:20:771-774 7. Agha FP, Dent TL, Fiddian-Green RG, Braunstein AH, Nostrant U. Bleed-
ing lipomas of the upper gastrointestinal tract: a diagnostic challenge. Am
Surg 1985:51 :279-285 8. Yatto RP. Colonic lipomatosis. Am J Gastroenterol 1982;77:436-437
D ow
nl oa
de d
fr om
w w
w .a
jr on
lin e.
or g
by 1
71 .2
43 .0
.1 61
o n
03 /1
1/ 23
f ro
m I
P ad
dr es
s 17
1. 24
3. 0.
16 1.
C op
yr ig
ht A
R R
S. F
or p
er so
Related Documents
