AJR 2002; 178:92
© American Roentgen Ray Society
Radiologic-Pathologic Conference of
St. Joseph's Hospital and
Medical Center |
CT of a Duodenal Angiomyolipoma
Leon R. Toye1 and
Lawrence A. Czarnecki2
1
Department of Radiology, St. Joseph's Hospital and Medical Center, 350 W.
Thomas Rd., Phoenix, AZ 85013.
2
Department of Pathology, St. Joseph's Hospital and Medical Center, Phoenix, AZ
85013.
Received May 7, 2001;
accepted after revision July 10, 2001.
Address correspondence to L. R. Toye.
Introduction
A 60-year-old woman reported early satiety without vomiting, pain, or
melena for 6 months. She had a medical history of only iron-deficient anemia
and diet-controlled diabetes. She had no history of tuberous sclerosis or
underlying malignancy.
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Fig. 1D. —60-year-old woman with 6-month history of early satiety.
Photomicrograph of histopathologic specimen shows mature adipocytes (thick
arrow) with intervening thick-walled blood vessels (thin arrow)
and spindle cells (arrowhead). (H and E, x100)
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Helical CT (LightSpeed QX/i; General Electric Medical Systems, Milwaukee,
WI) of the abdomen was performed with and without IV administration of 150 mL
of iohexol at 240 mg I/mL (Omnipaque; Nycomed, Princeton, NJ) and oral barium
contrast material.
CT revealed a 3.6 x 3.6 cm well-circumscribed predominantly
fat-containing mass in the bowel wall of the descending duodenum. This mass
displayed a small central area of soft-tissue density. Considerable
intraluminal mass effect was noted, with only a small portion of the
descending duodenal lumen remaining patent. There was no enhancement on the IV
contrast-enhanced images (Figs.
1A and
1B). A simple right-sided renal
cyst was also noted.
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Fig. 1A. —60-year-old woman with 6-month history of early satiety. CT
scan of abdomen reveals well-circumscribed predominantly fat-containing mass
in bowel wall of descending duodenum (arrow). Small central area of
soft-tissue density is seen in mass. Considerable intraluminal mass effect is
present. Incidental right renal cyst is seen.
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The patient underwent surgical excision of the lesion, and the descending
duodenum was resected. Postoperative gross evaluation revealed a polypoid
submucosal mass arising near the papilla of Vater
(Fig. 1C). Microscopic
examination of the polypoid mass showed a focally ulcerated and inflamed
duodenal mucosa overlying an expanded submucosa. The submucosa contained an
ill-defined mass of mature adipocytes with intervening thick-walled blood
vessels and spindle cells. The spindle cells resembled smooth muscle and were
positive for smooth-muscle actin and negative for S-100 protein and HMB-45.
The final pathologic diagnosis was angiomyolipoma.
Angiomyolipoma is a benign tumor composed of mature adipocytes and sheets
of smooth muscle; thick-walled blood vessels are present in an abnormal
arrangement. Typically, angiomyolipomas are seen in the kidney, where they may
present as incidental findings. The prevalence of renal angiomyolipomas is
between 0.3-3% [1,
2]. There are two clinical
variants: a sporadic form composes approximately 80% of cases, whereas the
remaining cases are associated with tuberous sclerosis and, less commonly,
lymphangiomyomatosis [1,
2].
To our knowledge, case reports of extrarenal angiomyolipomas are rare with
fewer than 50 cases reported. Although three cases of colonic and one case of
gastric angiomyolipoma exist, to our knowledge, no cases have been reported in
the small bowel. Other cases have been reported in the liver, retroperitoneum,
heart, lung, spinal cord, skin, nasal cavity, parotid gland, fallopian tube,
vaginal wall, spermatic cord, and penis. The liver is the most common site for
extrarenal angiomyolipoma [3,
4].
CT is an effective means of imaging and identifying renal angiomyolipomas.
Thin-section (3-5 mm) scanning is performed in an attempt to show fatty-tissue
attenuation. Renal angiomyolipomas are characteristically well marginated,
cortical-based, smaller than 5 cm, and predominately fatty (-160 to -20 H)
with heterogeneous soft tissue interspersed throughout. Contrast enhancement
is variable because of the amount of associated soft tissue. Sonography can
suggest the diagnosis but is not diagnostic, showing a well-defined
hyperechoic renal lesion. On MR imaging, lesions are bright on T1-weighted
images and dark on fat-suppressed images.
Radiologic diagnosis of extrarenal angiomyolipoma is difficult because of
the rarity of the condition. A lipoma would be the more probable diagnosis in
the radiologic differential of a fatty bowel lesion. A high index of suspicion
or a genetic predisposition may aid in the preoperative diagnosis.
References
-
Wagner B, Wong-You-Cheong J, Davis CJ. Adult renal hamartomas.
RadioGraphics
1997;17:155
-169[Abstract]
-
Helenon O, Merran S, Paraf F, et al. Unusual fatcontaining tumors
of the kidney: a diagnostic dilemma. RadioGraphics
1997;17:129
-144[Abstract]
-
Fegan J, Shah H, Mukunyadzi P, Schutz M. Extrarenal retroperitoneal
angiomyolipoma. South Med J
1997;90:59
-62[Medline]
-
Sajima S, Kinoshita H, Okuda K, et al. Angiomyolipoma of the liver:
a case report and review of 48 cases reported in Japan [in Japanese].
Kurume Med J
1999;46:127
-131[Medline]
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Introduction
References
