Figure 1
Ultrasound
Ultrasound image showing cystic mass ventral to the right kidney. The mass displays the characteristic “gut signature” wall, with an echogenic inner (mucosal) lining, and an outer echopoor rim.
Gastric-outlet obstruction in a neonate with a duodenal duplication cyst
SectionPaediatric radiology
Case TypeClinical Cases
AuthorsBlair PS, Mahmood A, McCullagh M, Paterson A.
Connected authors
1 months, female
Clinical History
A neonate pesented with symptoms and signs of gastric-outlet obstrucation at four weeks of age. She had an antenatal diagnosis of a cystic abdominal mass lesion which when imaged on day one of life was felt to be an enteric duplication cyst.
Imaging Findings
The incidental discovery of an intra-abdominal, unilocular, walled-off cyst occurred during routine ultrasound scanning at 36 weeks gestation. The cyst, seen inferior to the liver had no apparent connection to the renal tract or stomach, was presumed to be a duplication cyst arising from the antro-pylorus or duodenum. The paediatric surgical team advised follow-up by means of transabdominal ultrasound.
Ultrasound examination on the first postnatal day confirmed a well-defined hypoechoic structure beneath the liver margin, encroaching on the midline. The mass measured 4.0 x 4.9 cm in diameter. A multilayered wall with an echogenic lining was visualised and the cyst was seen to lie in close relation to the pylorus and first part of duodenum. The appearances were in keeping with a duplication cyst. A radiograph of the spine did not show any vertebral anomalies.
The baby was discharged home with elective admission for excision of the cyst planned for the near future. One month later, she presented with a four day history of intractable non-bilious vomiting; features in keeping with gastric-outlet obstruction.
Repeat ultrasound did not reveal any change in the cystic mass. An MRI scan of abdomen, performed to ensure there was no connection with the spinal canal, confirmed the sonographic findings.
Subsequent surgery confirmed the cyst arose in the angle between the first and second parts of the duodenum. It was unsafe to remove the cyst entirely; the portion not adherent to the duodenum was resected and the remainder stripped of its mucosal lining.
Ultrasound examination on the first postnatal day confirmed a well-defined hypoechoic structure beneath the liver margin, encroaching on the midline. The mass measured 4.0 x 4.9 cm in diameter. A multilayered wall with an echogenic lining was visualised and the cyst was seen to lie in close relation to the pylorus and first part of duodenum. The appearances were in keeping with a duplication cyst. A radiograph of the spine did not show any vertebral anomalies.
The baby was discharged home with elective admission for excision of the cyst planned for the near future. One month later, she presented with a four day history of intractable non-bilious vomiting; features in keeping with gastric-outlet obstruction.
Repeat ultrasound did not reveal any change in the cystic mass. An MRI scan of abdomen, performed to ensure there was no connection with the spinal canal, confirmed the sonographic findings.
Subsequent surgery confirmed the cyst arose in the angle between the first and second parts of the duodenum. It was unsafe to remove the cyst entirely; the portion not adherent to the duodenum was resected and the remainder stripped of its mucosal lining.
Discussion
Enteric duplication cysts are uncommon congenital malformations. They are defined as spherical or tubular cystic structures lined with alimentary tract epithelium, which are usually attached to the gastrointestinal tract [1]. Whilst they may arise from any part of the gastrointestinal tract, all have the following characteristics:
1. Proximity to the alimentary canal.
2. A common blood supply with the adjacent portion of alimentary canal.
3. An outer smooth muscle coat, usually common with the adjacent alimentary canal.
4. An alimentary epithelial lining (not necessarily of the same type as the adjacent gut) 2
The most prevalent location for a duplication cyst is the distal ileum, followed by the oesophagus and colon [1] Gastric duplications are seen in only 3.8%, with the rarer subtype of pyloric duplications seen in only 2.2% of these cases [3, 4]. The commonest position for a gastric duplication is along the greater curve; more often than not there is no communication with the stomach. Associated anomalies include other enteric duplications, and vertebral segmentation anomalies, which may be found in up to 50% of patients [2].
Whilst the exact aetiology for the formation of enteric cysts is unknown, a number of different theories have been postulated. Incomplete twinning, persistent embryological diverticula and split notochord hypotheses are all recognised [2].
Gastroduodenal duplication cysts are rare; only a few cases have been reported in the literature [2]. A third present in the neonatal period, typically with an abdominal mass. The majority of the remainder present later with symptoms of gastric outlet obstruction [3]. That said, at least three case reports have described neonates presenting with intractable non-bilious vomiting caused by pyloric duplication cysts [2, 3, 4]. Of these, one was diagnosed antenatally as having a cystic mass in the upper abdomen, as was our patient [3]. Other presentations of pyloric duplication cysts include: recurrent peptic ulceration, gastrointestinal haemorrhage or hypergastrinaemia, but the exact clinical features vary according to the precise site and nature of the cyst [4].
Surgery is the mainstay of treatment for pyloric duplication cysts. It may be possible to excise the cyst with or without a margin of the adjacent stomach. However, in more complex cases pyloroantrectomy and even gastrectomy have been reported. In all approaches, it is essential to remove all of the cyst lining, to prevent recurrence [2, 4].
The imaging characteristics of an enteric duplication cyst include: an elongated tubular or spherical sonolucent mass, with good through transmission, which parallels the bowel lumen. The ''muscular rim'' or ''gut signature'' sign of an echogenic inner mucosal lining and hypoechoic outer rim is regarded as characteristic [5]. All of these features were seen in this case.
The improved ultrasonic resolution and increased pick-up rates of pathology on routine antenatal ultrasound scanning, allow the visualisation and recognition of duplication cysts prior to birth. This means the appropriate paediatric surgical team can be consulted and an elective surgical procedure planned before the onset of clinical symptoms to avoid the risks involved with emergency surgery.
1. Proximity to the alimentary canal.
2. A common blood supply with the adjacent portion of alimentary canal.
3. An outer smooth muscle coat, usually common with the adjacent alimentary canal.
4. An alimentary epithelial lining (not necessarily of the same type as the adjacent gut) 2
The most prevalent location for a duplication cyst is the distal ileum, followed by the oesophagus and colon [1] Gastric duplications are seen in only 3.8%, with the rarer subtype of pyloric duplications seen in only 2.2% of these cases [3, 4]. The commonest position for a gastric duplication is along the greater curve; more often than not there is no communication with the stomach. Associated anomalies include other enteric duplications, and vertebral segmentation anomalies, which may be found in up to 50% of patients [2].
Whilst the exact aetiology for the formation of enteric cysts is unknown, a number of different theories have been postulated. Incomplete twinning, persistent embryological diverticula and split notochord hypotheses are all recognised [2].
Gastroduodenal duplication cysts are rare; only a few cases have been reported in the literature [2]. A third present in the neonatal period, typically with an abdominal mass. The majority of the remainder present later with symptoms of gastric outlet obstruction [3]. That said, at least three case reports have described neonates presenting with intractable non-bilious vomiting caused by pyloric duplication cysts [2, 3, 4]. Of these, one was diagnosed antenatally as having a cystic mass in the upper abdomen, as was our patient [3]. Other presentations of pyloric duplication cysts include: recurrent peptic ulceration, gastrointestinal haemorrhage or hypergastrinaemia, but the exact clinical features vary according to the precise site and nature of the cyst [4].
Surgery is the mainstay of treatment for pyloric duplication cysts. It may be possible to excise the cyst with or without a margin of the adjacent stomach. However, in more complex cases pyloroantrectomy and even gastrectomy have been reported. In all approaches, it is essential to remove all of the cyst lining, to prevent recurrence [2, 4].
The imaging characteristics of an enteric duplication cyst include: an elongated tubular or spherical sonolucent mass, with good through transmission, which parallels the bowel lumen. The ''muscular rim'' or ''gut signature'' sign of an echogenic inner mucosal lining and hypoechoic outer rim is regarded as characteristic [5]. All of these features were seen in this case.
The improved ultrasonic resolution and increased pick-up rates of pathology on routine antenatal ultrasound scanning, allow the visualisation and recognition of duplication cysts prior to birth. This means the appropriate paediatric surgical team can be consulted and an elective surgical procedure planned before the onset of clinical symptoms to avoid the risks involved with emergency surgery.
Differential Diagnosis List
Gastric-outlet obstruction caused by duplication cyst arising from the duodenum.
Final Diagnosis
Gastric-outlet obstruction caused by duplication cyst arising from the duodenum.
References
[1] Hur J, Yoon C-S, Kim M-J, Kim O-H (2007) Imaging features of gastrointestinal tract duplications in infants and children: from oesophagus to rectum. Pediatr Radiol 37:691-699. (PMID: 17541575)
[2] Patel MP, Meisheri IV, Waingankar VS, Ramesh S, Naregal AM, Muthaal PB (1997) Duplication cyst of the pylorus-a rare cause of gastric outlet obstruction in the newborn. J Postgrad Med 43:43-45. (PMID: 10740718)
[3] Shah A, More B, Buick R (2005) Pyloric duplication in the neonate: a rare entity. Pediatr Surg Int 21:220-222. (PMID: 15578189)
[4] Sinha CK, Nour S, Fisher R (2007) Pyloric duplication in the newborn: A rare cause of gastric outlet obstruction. J Indian Assoc Pediatr Surg 12:34-35.
[5] Cheng G, Soboleski D, Daneman A, Poenaru D, Hurlbut D (2005) Sonographic Pitfalls in the Diagnosis of Enteric Duplication Cysts. AJR Am J Roentgenol 184:521-525. (PMID: 15671373)
Case information
| URL: | https://www.eurorad.org/case/7034 |
| DOI: | 10.1594/EURORAD/CASE.7034 |
| ISSN: | 1563-4086 |
Figure 2
Ultrasound
Ultrasound image showing the cyst in the right upper quadrant of the abdomen, inferior to the hepatic margin. The cyst is seen to be remote from the common hepatic duct.
Figure 3
MRI abdomen
T2-weighted sequence from MRI of abdomen showing high signal cystic like structure in the upper abdomen separate from the gallbladder and common hepatic duct.
Figure 4
Intraoperative photograph
Intraoperative photograph of cyst arising from duodenum.
Ultrasound
Ultrasound image showing cystic mass ventral to the right kidney. The mass displays the characteristic “gut signature” wall, with an echogenic inner (mucosal) lining, and an outer echopoor rim.
Ultrasound
Ultrasound image showing the cyst in the right upper quadrant of the abdomen, inferior to the hepatic margin. The cyst is seen to be remote from the common hepatic duct.
MRI abdomen
T2-weighted sequence from MRI of abdomen showing high signal cystic like structure in the upper abdomen separate from the gallbladder and common hepatic duct.
Intraoperative photograph
Intraoperative photograph of cyst arising from duodenum.