This document discusses different types of cysts, including their definitions, characteristics, locations and imaging appearances. It provides examples of cysts in the hepatobiliary system (choledochal cyst, gallbladder hydrops), gastrointestinal system (duplication cyst, omental/mesenteric cyst), urinary tract (renal cysts, urachal cyst), adrenals (resolving hemorrhage, neuroblastoma), pancreas (pseudocyst), and pelvis (ovarian cysts, dermoid cyst, abscess). For each location, the document describes features on ultrasound, CT, MRI and other imaging to help differentiate cyst types and guide diagnosis.

1. Asha Sheth, MD
June 25,2014

2. What is a cyst?
Types of cysts
Differentials
Imaging appearances

3.  Closed pocket or pouch of tissue
 It can be filled with air, fluid, pus,
or other material

4.  Thin /Thick walled
 With / Without wall calcifications
 Regular/ Irregular in shape
 Small / Large in size
 With / Without internal septa
• Thin / Thick
• Single / Multiple
 With /Without Solid component

5.  HEPATOBILIARY
• Choledochal Cyst
• Gallbladder Hydrops
 GASTROINTESTINAL
• Duplication Cyst
• Omental/Mesenteric Cyst
 URINARY TRACT
• Renal /parapelvic Cyst
• Severe Hydronephrosis/Pelviureteric junction
Obstuction.
• Cystic Wilm’s Tumour (rare)
• Urachal Cyst

6.  ADRENALS
• Resolving adrenal heamorrhage
• Cystic neuroblastoma/Ganglioneuroma(rare)
 PANCREATIC
• Pancreatic pseudocyst
 PELVIC
• Ovarian Cyst
• Teratoma/Dermoid Cyst
• Anterior Meningocele
• Abscess

7.  CHOLEDOCHAL CYST
 GALLBLADDER HYDROPS

8.  Congenital dilatations of the biliary tree
 Most cause symptoms in childhood and
adult life
 Todani’s classification
• Type I- Fusiform
• TypeII- Diverticulum
• Type IlI- Choledochocele of intraduodenal
common bile duct
• Type IV- Extra- and intrahepatic cysts
• Type V- Intrahepatic dilatations (Caroli’s Disease)

10.  Complications include cholangitis, biliary
calculi, pancreatitis and biliary cirrhosis
 Biliary tree dilatation or cyst can be seen on
Ultrasound or CT
 99mTc-HIDA scinitraphy will show accumulation
of tracer within the cyst
 Percutanous or endoscopic cholangiography and
MRCP are helpful in preoperative planning

11. Fusiform choledochal cyst with a long common channel
and associated stricture at the pancreaticobiliary
junction.

13. Ultrasound study shows a cystic mass between pancreatic head and the
gallbladder. Smooth wall and homogeneous anechoic contents, tortuous
cystic duct that joins the gall bladder to the cystic mass

15.  Duplication Cyst
 Omental/Mesenteric Cyst

16.  May occur anywhere along the gastrointestinal
tract
 The most frequent sites of duplication are the
ileum, followed by esophagus, stomach,
duodenum and jejunum
• 1/3rd of cases involve the distal small bowel
 Colonic and rectal duplications are rare
 Etiology is incomplete recanalization around 8
weeks gestation
 Cysts lined with GI epithelium

17. Can be spherical or tubular
Most duplications do not communicate
with the adjacent bowel, although there
is a higher incidence of persistent
communication in tubular anomalies
Presentation depends on the site of
duplication and its size
Incidental ultrasound finding in the first
few years of life

18.  Large cysts, especially those associated with
the stomach or duodenum, may present with
• Abdominal pain
• Obstruction
• Vomiting
 Can serve as lead point for intussusception
 Be a source of gastrointestinal bleeding from
ectopic gastric mucosa

19.  Abdominal radiographs may show mass
effect with displacement of adjacent bowel
loops
 Ultrasound demonstrates a simple anechoic
or hypoechoic cyst
• characteristic 'gut-wall signature'
 TREATMENT: Surgical resection

20. Abdominal x-ray of a patient with a duplication cyst. Note the mass effect of the cyst
pressing against the areas of colon (arrows).

21. Simple cystic mass with characteristic gut wall signature

22. Gastric duplication cyst causing gastric outlet
obstruction in a pediatric patient

23. Contrast-enhanced computed tomography image of the abdomen showing a well-
circumscribed, low-attenuation fluid collection seen in relation to the greater curvature
of the stomach with rim enhancement, suggestive of an intestinal duplication cyst

24.  Developmental anomalies of the
lymphatic system arising within the
mesentery or omentum
 Presentation is similar to duplication cysts
 Ultrasound is more likely to show a
multiloculated cyst with thin septations
 Require surgical resection

25. Mesenteric cyst
CT demonstrating a large left-sided cystic
abdominal mass with compression of the left kidney.
Ultrasound showed multiple fine septations within the cyst

26. Lymphangioma has enhancing septa. Unlike in cystic peritoneal
metastases, ascites is not a feature of lymphangioma.
When you see a septated cystic lesion without ascites the most likely
diagnosis is a lymphangioma.

27. Notice that CT does not always appreciate the
septations, although the specimen clearly
shows multiple septations.

29. Renal /Parapelvic Cyst
Severe Hydronephrosis/UPJ obstruction
Cystic Wilm’s Tumour (rare)
Urachal Cyst

36. Severe hydronephrosis with
proximal hydroureter

43. Resolving adrenal
heamorrhage
 Cystic neuroblastoma/
Ganglioneuroma(rare)

44. commonest cause of an adrenal mass
Associated with perinatal stress,
hypoxia, septicaemia and hypotension
may be unilateral or bilateral
Adrenal insufficiency is rare, even in
bilateral cases.
Ultrasound in the first few days of life
usually demonstrates an avascular
heterogenous adrenal mass that
becomes cystic and smaller over the
following weeks as clot retraction

47. Over half of them arise in the adrenals,
but 30% can arise
from sympathetic tissue elsewhere in
the abdomen
Calcification has been noted to occur in
over 50% of Cases
Ganglioneuroma is a mature form of
neurogenic tumour.
Calcification helps in suggesting a
diagnosis of neurogenic tumour

48. Adrenal ganglioneuroma with
hepatic metastasis

49. Pancreatic pseudocyst

50.  well-known complication of pancreatitis
 fluid collections may occur within the
pancreatic mass, or
in the peripancreatic spaces, or
elsewhere within the abdomen
following either acute / chronic pancreatitis
 In acute pancreatitis, the pseudocyst
contains enzyme-rich fluid and products of
autodegradation of the pancreas
 in chronic pancreatitis the cyst is a
consequence of duct obstruction.

51. Patients who have persistent abdominal
pain or persistently elevated levels of
pancreatic enzymes should be
suspected of harbouring a pseudocyst
one-third of pancreatic pseudocysts
will resolve spontaneously

54. Pancreatic pseudocyst Large septated cystic mass in the mid abdomen with
nodular component. In the absence of history of pancreatitis it would be
difficult to differentiate this from a cystic pancreatic tumour.

56.  Ovarian Cyst
 Teratoma/Dermoid Cyst
 Anterior Meningocele
 Abscess

57.  Cysts are fluid filled spaces within the ovary.
 very common and could be physiological /
pathological, benign/ malignant
 Functional or physiological cysts are either
follicular or of corpus luteum origin.
 Follicular cysts form when a follicle fails to
rupture at midcycle leading to its continuous
enlargement. Usually these cysts are
asymptomatic and disappear without any
intervention within one or two months
 Similarly a persistent corpus luteum might fail
to disintegrate before menstruation and
enlarge in size

58. Both follicular and luteal cysts could
become haemorrhagic if bleeding occured
within them leading to rapid increase in
size and severe pain.
they might cause severe pain only if they
are large in size (>7 cm) and cause
pressure symptoms or torsion of the
whole ovary compromising blood flow
when surgical intervention is indicated

60. A simple ovarian cyst on the right side of the uterus

61. Haemorrhagic ovarian cyst

62. A teratoma is an encapsulated tumor
with tissue or organ components
resembling normal derivatives of more
than one germ layer
They therefore contain
developmentally mature skin complete
with hair follicles and sweat glands,
sometimes luxuriant clumps of long
hair, and often pockets of sebum,
blood, fat, bone, nails, teeth, eyes,
cartilage, and thyroid tissue.

67.  A pus-filled cavity in the pelvis due to
infection
 A pelvic abscess is the end stage in the
progression of a genital tract infection and is
frequently an unnecessary complication
 Treatment : Surgical drainage of abscess and
dead tissue removal/ antibiotics

68. Abdominal computed
tomography showed pelvic
abscess (asterisk) and right tubo-
ovarian abscess (arrow).

69. Cysts may have different characteristics
and origins
Location, appearances, multi modality
can help in the diagnosis