- Email: [email protected]
Inverted Meckel's diverticulum
089561 I l/89 S3.00 + .OO
ComputoizdMedical Imaging and Graphics, Vol. 13, No. 6, pp. 417-479,1989 Printed in the U.S.A. All rights reserved.
Copyright Q 1989 Pqmnon
Press plc
INVERTED MECKEL’S DIVERTICULUM Yu Men Chen’, Randall S. Teague2, Neil T. Wolfman’ and David J. Ott’ ‘Department of Radiology, Bowman Gray School of Medicine, Wake Forest University, Winston-Salem, NC 27 103, and *Department of Radiology, Randolph Medical Center, Asheboro, NC 27204 (Received 9 March 1989)
Abstract-Although Meckel’s diverticulum is a relatively common anomaly, inverted Meckel’s diverticulum has been reported rarely. We describe a 5kyear-old woman with inverted Meckel’s diverticulum located at the distal ileum simulating a benign tumor. Computed tomography density, and appearance not described previously.
showed a small mass with a central area of low fat
Key Words: Meckel’s diverticulum, Diverticulum
Meckel’s diverticulum, one of the most common anomalies of the gastrointestinal tract, occurs in about 2-3% of the general population (1). However, inverted Meckel’s diverticulum is rare and usually appears as a benign mass or intussusception on the small bowel study (1, 2). Computed tomography (CT) of inverted Meckel’s diverticulum has infrequently been reported (3). We describe a 59-year-old woman with inverted Meckel’s diverticulum in the distal ileum mimicking a benign tumor and presenting as a central area of low fat density on CT. CASE
or malignant neoplasm, intussusception, or inverted Meckel’s diverticulum. At operation, an inverted Meckel’s diverticulum measuring 4.5 cm X 2.5 cm was found in the distal ileum and resected. The mucosal lining of the small bowel appeared normal. There was a 1 cm ulceration near the mouth of the diverticulum and another 0.7 cm ulcer at its tip. The mesenteric lymph nodes were unremarkable. Permanent slides revealed focal mucosal ulceration in the distal portion of the Meckel’s diverticulum without ectopic gastric mucosa or malignancy. The patient had an uneventful recovery.
REPORT
A 59-year-old woman was evaluated for anemia. She had a history of hypertension, peptic ulcer, and cholecystectomy. The physical examination was unremarkable. Her hemoglobin was 8 g/ 100 ml and she had a positive stool guaiac test. An upper gastrointestinal series showed only small hiatal hernia. Double-contrast barium enema was normal except for large diverticula in the ascending colon. Standard small bowel examination identified a nonspecific elongated 1.5 X 6 cm filling defect in a lower abdominal ileal loop. The mass appeared changeable without adjacent loop fixation or small bowel caliber changes. Enteroclysis performed one week later confirmed this elongated ileal mass (Fig. 1). Subsequent abdominal and pelvic CT with oral contrast solution demonstrated the mass with a central area of fat density in the right lower abdomen (Fig. 2). Differential considerations included benign Fig. 1. Enteroclysis showing an intraluminal polypoid mass at the borderline of an interssusception within the barium-
Reprint requests to: Yu Men Chen, M.D., Department of Radiology, Bowman Gray School of Medicine, Winston-Salem, NC 27 103.
filled distal ileum (arrow).
477
478
Computerized Medical Imaging and Graphics
November-December/ 1989, Volume 13, Number 6
Fig. 2. CT scan showing a mass (arrow) within oral contrast solution in the distal ileum. A central fat density was seen in the mass.
DISCUSSION
Meckel’s diverticula, occurring in about 2-3% of the population, is one of the most common congenital anomalies of the gastrointestinal tract (1). It is estimated that 2.5-5% of small bowel intussusceptions are caused by Meckel’s diverticula (4). Only six cases of inverted Meckel’s diverticula have been reported previously in the English language literature (2,4-7). Meckel’s diverticulum is usually asymptomatic and found incidentally. Massive or chronic rectal bleeding is a common complication often caused by ectopic gastric mucosa. Intussusception is another complication of Meckel’s diverticulum. Abdominal pain and distention, nausea, vomiting, diarrhea, or intestinal obstruction may be other clinical presentations. On small bowel studies, Meckel’s diverticulum typically appears as a saccular outpouching on the antimesenteric border of the ileum. An inverted Meckel’s diverticulum usually appears as a nonspecific polypoid mass in the lumen of the distal ileum, as in our case. The inverted anomaly has a smooth contour and mimics a benign or malignant neoplasm. All reported inverted Meckel’s diverticula have had a similar appearance. In one case, partial small bowel obstruction was present (7). The role of abdominal CT in evaluating inverted Meckel’s diverticula is unclear due to the rarity of the complication. A large Meckel’s diverticulum may
appear as an elongated cystic structure directly attached to a distal bowel loop (1). The fibrous remnant of the vitelline duct may also be visible as a band of soft tissue density between the Meckel’s diverticulum and the posterior aspect of the umbilicus. The presence of a calcified enterolith and luminal contrast material assists the CT diagnosis of Meckel’s diverticulum and its differentiation from mesenteric cysts or intestinal duplication. In our case, a central area of fat density, representing mesenteric fat, with well-defined margins within a mass is considered a CT sign of inverted Meckel’s diverticulum. The core of the small bowel intussusception may have sausage-like or crescentshape fat density representing mesentery fat and lymph nodes between intussusceptum and intussuscipien (3). Some primary malignancies of the ileum, such as lymphoma, leiomyosarcoma, a necrotic metastases from lung cancer, endometrial carcinoma, gastric cancer, or colonic cancer may also show a central area of water density within a mass (1). However, the necrotic cavity usually has a water density higher than fat and irregular margins. Infected Meckel’s diverticulum may also show a mass with central water density but it has clinical manifestations of inflammation (8). REFERENCES 1. Ghahremani, G.G. Radiology of Meckel’s diverticulum. CRC Crit. Rev. D&I. Imaging 26: l-43; 1986.
Inverted Meckel’s diverticulum 0 Y. M. 2. Freeny, P.C.; Walker, J.H. Inverted diver&da of the gastrointestinal tract. Gastrointest. Radiol. 457-59; 1979. 3. Lee, J.K.T.; !&gel, S.S.; Stanley, R.J. Computed body tomography. New York: Raven Press; 1983. 4. Gay, B.B., Jr. Radiologic demonstration of an invaginated intussuscepted Meckel’s diverticulum. Radiology 60:60-63; 1953. of 5. Shull, L.N. Jr.; Jones, E.E. Chronic intussusception Meckel’s diverticulum. J. SC. Med. Assoc. 71:363-365; 1975. 6. Boldero, J.L. Inverted Meckel’s diverticulum as a cause of anaemia and continuing blood loss. Br. J. Radiol. 5 1:829-830; 1978. 7. Silver, B.; Demos, T. Symptomatic inverted Meckel’s divertio ulum: case report. J. Can. Assoc. Radiol. 34314-315; 1983. 8. Russ, P.D.; Friefeld, G.D.; Nauck, C.J.; Wilmouth, R.J. Infarcted Meckel diverticulum detected by CT. AJR 150:299300; 1988.
About the Author-DR. Yu MEN CHEN received his M.D. from the Shanghai Chinese Medical School in 1964. He completed his radiology residency at the Yang Poo Medical Center. In addition, he was a resident and a practicing radiologist at the Shanghai Chinese Medical Hospital. He was a research fellow at the Bowman
CHEN et al.
479
Gray School of Medicine and is currently a Research Assistant Professor there. About the Author-RANDALL Scorr TEAGuE received the B.S. degree from the University of North Carolina in 1970, and the M.D. degree from the Bowman Gray School of Medicine of Wake Forest University in 1974. Afier serving as Director of the Emergency Department at Randolph Hospital, Dr. Teague returned to Bowman Gray School of Medicine for a residency in radiology. He is now a member of Randolph Radiological Associates, Inc. About the Author-DR. WOLFMANreceived a B.A. degree for New York University. He attended the University of Bologna School of Medicine and received his M.D. degree from Albany Medical College of Union University. He was a resident and teaching fellow at the University Health Center of Pittsburgh. Dr. Wolfman completed a fellowship in imaging (ultrasound/computed tomography) at the University of Pittsburgh Health Center. He is presently the Chief of CT/Ultrasound at Bowman Gray School of Medicine. About the Author-DR. DAVID JAMB Gr’r received his M.D. from the University of Michigan Medical School in 197 1. He completed his internship and residency at North Carolina Baptist Hospital. Dr. Ott began as an Instructor in 1977 at the Bowman Gray School of Medicine and is currently a Professor in the Department of Radiology there.
ComputoizdMedical Imaging and Graphics, Vol. 13, No. 6, pp. 417-479,1989 Printed in the U.S.A. All rights reserved.
Copyright Q 1989 Pqmnon
Press plc
INVERTED MECKEL’S DIVERTICULUM Yu Men Chen’, Randall S. Teague2, Neil T. Wolfman’ and David J. Ott’ ‘Department of Radiology, Bowman Gray School of Medicine, Wake Forest University, Winston-Salem, NC 27 103, and *Department of Radiology, Randolph Medical Center, Asheboro, NC 27204 (Received 9 March 1989)
Abstract-Although Meckel’s diverticulum is a relatively common anomaly, inverted Meckel’s diverticulum has been reported rarely. We describe a 5kyear-old woman with inverted Meckel’s diverticulum located at the distal ileum simulating a benign tumor. Computed tomography density, and appearance not described previously.
showed a small mass with a central area of low fat
Key Words: Meckel’s diverticulum, Diverticulum
Meckel’s diverticulum, one of the most common anomalies of the gastrointestinal tract, occurs in about 2-3% of the general population (1). However, inverted Meckel’s diverticulum is rare and usually appears as a benign mass or intussusception on the small bowel study (1, 2). Computed tomography (CT) of inverted Meckel’s diverticulum has infrequently been reported (3). We describe a 59-year-old woman with inverted Meckel’s diverticulum in the distal ileum mimicking a benign tumor and presenting as a central area of low fat density on CT. CASE
or malignant neoplasm, intussusception, or inverted Meckel’s diverticulum. At operation, an inverted Meckel’s diverticulum measuring 4.5 cm X 2.5 cm was found in the distal ileum and resected. The mucosal lining of the small bowel appeared normal. There was a 1 cm ulceration near the mouth of the diverticulum and another 0.7 cm ulcer at its tip. The mesenteric lymph nodes were unremarkable. Permanent slides revealed focal mucosal ulceration in the distal portion of the Meckel’s diverticulum without ectopic gastric mucosa or malignancy. The patient had an uneventful recovery.
REPORT
A 59-year-old woman was evaluated for anemia. She had a history of hypertension, peptic ulcer, and cholecystectomy. The physical examination was unremarkable. Her hemoglobin was 8 g/ 100 ml and she had a positive stool guaiac test. An upper gastrointestinal series showed only small hiatal hernia. Double-contrast barium enema was normal except for large diverticula in the ascending colon. Standard small bowel examination identified a nonspecific elongated 1.5 X 6 cm filling defect in a lower abdominal ileal loop. The mass appeared changeable without adjacent loop fixation or small bowel caliber changes. Enteroclysis performed one week later confirmed this elongated ileal mass (Fig. 1). Subsequent abdominal and pelvic CT with oral contrast solution demonstrated the mass with a central area of fat density in the right lower abdomen (Fig. 2). Differential considerations included benign Fig. 1. Enteroclysis showing an intraluminal polypoid mass at the borderline of an interssusception within the barium-
Reprint requests to: Yu Men Chen, M.D., Department of Radiology, Bowman Gray School of Medicine, Winston-Salem, NC 27 103.
filled distal ileum (arrow).
477
478
Computerized Medical Imaging and Graphics
November-December/ 1989, Volume 13, Number 6
Fig. 2. CT scan showing a mass (arrow) within oral contrast solution in the distal ileum. A central fat density was seen in the mass.
DISCUSSION
Meckel’s diverticula, occurring in about 2-3% of the population, is one of the most common congenital anomalies of the gastrointestinal tract (1). It is estimated that 2.5-5% of small bowel intussusceptions are caused by Meckel’s diverticula (4). Only six cases of inverted Meckel’s diverticula have been reported previously in the English language literature (2,4-7). Meckel’s diverticulum is usually asymptomatic and found incidentally. Massive or chronic rectal bleeding is a common complication often caused by ectopic gastric mucosa. Intussusception is another complication of Meckel’s diverticulum. Abdominal pain and distention, nausea, vomiting, diarrhea, or intestinal obstruction may be other clinical presentations. On small bowel studies, Meckel’s diverticulum typically appears as a saccular outpouching on the antimesenteric border of the ileum. An inverted Meckel’s diverticulum usually appears as a nonspecific polypoid mass in the lumen of the distal ileum, as in our case. The inverted anomaly has a smooth contour and mimics a benign or malignant neoplasm. All reported inverted Meckel’s diverticula have had a similar appearance. In one case, partial small bowel obstruction was present (7). The role of abdominal CT in evaluating inverted Meckel’s diverticula is unclear due to the rarity of the complication. A large Meckel’s diverticulum may
appear as an elongated cystic structure directly attached to a distal bowel loop (1). The fibrous remnant of the vitelline duct may also be visible as a band of soft tissue density between the Meckel’s diverticulum and the posterior aspect of the umbilicus. The presence of a calcified enterolith and luminal contrast material assists the CT diagnosis of Meckel’s diverticulum and its differentiation from mesenteric cysts or intestinal duplication. In our case, a central area of fat density, representing mesenteric fat, with well-defined margins within a mass is considered a CT sign of inverted Meckel’s diverticulum. The core of the small bowel intussusception may have sausage-like or crescentshape fat density representing mesentery fat and lymph nodes between intussusceptum and intussuscipien (3). Some primary malignancies of the ileum, such as lymphoma, leiomyosarcoma, a necrotic metastases from lung cancer, endometrial carcinoma, gastric cancer, or colonic cancer may also show a central area of water density within a mass (1). However, the necrotic cavity usually has a water density higher than fat and irregular margins. Infected Meckel’s diverticulum may also show a mass with central water density but it has clinical manifestations of inflammation (8). REFERENCES 1. Ghahremani, G.G. Radiology of Meckel’s diverticulum. CRC Crit. Rev. D&I. Imaging 26: l-43; 1986.
Inverted Meckel’s diverticulum 0 Y. M. 2. Freeny, P.C.; Walker, J.H. Inverted diver&da of the gastrointestinal tract. Gastrointest. Radiol. 457-59; 1979. 3. Lee, J.K.T.; !&gel, S.S.; Stanley, R.J. Computed body tomography. New York: Raven Press; 1983. 4. Gay, B.B., Jr. Radiologic demonstration of an invaginated intussuscepted Meckel’s diverticulum. Radiology 60:60-63; 1953. of 5. Shull, L.N. Jr.; Jones, E.E. Chronic intussusception Meckel’s diverticulum. J. SC. Med. Assoc. 71:363-365; 1975. 6. Boldero, J.L. Inverted Meckel’s diverticulum as a cause of anaemia and continuing blood loss. Br. J. Radiol. 5 1:829-830; 1978. 7. Silver, B.; Demos, T. Symptomatic inverted Meckel’s divertio ulum: case report. J. Can. Assoc. Radiol. 34314-315; 1983. 8. Russ, P.D.; Friefeld, G.D.; Nauck, C.J.; Wilmouth, R.J. Infarcted Meckel diverticulum detected by CT. AJR 150:299300; 1988.
About the Author-DR. Yu MEN CHEN received his M.D. from the Shanghai Chinese Medical School in 1964. He completed his radiology residency at the Yang Poo Medical Center. In addition, he was a resident and a practicing radiologist at the Shanghai Chinese Medical Hospital. He was a research fellow at the Bowman
CHEN et al.
479
Gray School of Medicine and is currently a Research Assistant Professor there. About the Author-RANDALL Scorr TEAGuE received the B.S. degree from the University of North Carolina in 1970, and the M.D. degree from the Bowman Gray School of Medicine of Wake Forest University in 1974. Afier serving as Director of the Emergency Department at Randolph Hospital, Dr. Teague returned to Bowman Gray School of Medicine for a residency in radiology. He is now a member of Randolph Radiological Associates, Inc. About the Author-DR. WOLFMANreceived a B.A. degree for New York University. He attended the University of Bologna School of Medicine and received his M.D. degree from Albany Medical College of Union University. He was a resident and teaching fellow at the University Health Center of Pittsburgh. Dr. Wolfman completed a fellowship in imaging (ultrasound/computed tomography) at the University of Pittsburgh Health Center. He is presently the Chief of CT/Ultrasound at Bowman Gray School of Medicine. About the Author-DR. DAVID JAMB Gr’r received his M.D. from the University of Michigan Medical School in 197 1. He completed his internship and residency at North Carolina Baptist Hospital. Dr. Ott began as an Instructor in 1977 at the Bowman Gray School of Medicine and is currently a Professor in the Department of Radiology there.