This is a 59-year-old patient with widely metastatic breast cancer who developed severe abdominal pain. A computed tomography (CT) scan of the abdomen shows a stone impacted in the cystic duct. A hepatobiliary iminodiacetic acid (HIDA) scan revealed nonfilling of the gallbladder. Magnetic resonance cholangiopancreatography (MRCP) was performed to rule out a common bile duct stone because the patient’s bilirubin level was mildly elevated. No stone was seen in the common bile duct. The interesting abnormality in the distal common bile duct (choledochocele vs. web) is discussed in the Liver section of this chapter. The EUS images (Fig. 5.5) show echogenic bile and a thickened gallbladder wall but no pericholecystic fluid and no stones in the gallbladder itself. During surgery the gallbladder was densely adherent to the liver and filled with pus. A stone was stuck in the cystic duct.

When diagnosed incidentally during cholecystectomy, surgical resection can be curative. However, most often the tumor is unresectable at the initial presentation of the patient. Fortunately, gallbladder cancer is rare in North America. The highest incidence of gallbladder cancer is found among Andean populations, North American Indians, and Mexican Americans [3]. Early diagnosis could improve the clinical outcome and cure rate. However, conventional imaging modalities such as transcutaneous abdominal ultrasound and CT can be difficult to interpret, as this case shows. This is an 84-year-old patient who initially presented with obstructive jaundice. Endoscopic retrograde cholangiopancreatography (ERCP) performed by a different examiner revealed a stricture of the common hepatic duct, which was stented. The gallbladder did not fill. The abnormalities on the CT scan suggesting a gallbladder mass were initially not appreciated, presumably because there were other more impressive things to be seen, such as a large pseudocyst. A HIDA scan was ordered and showed nonfilling of the gallbladder. Cholecystitis was suspected and, because of the patient’s debilitated state, arrangements were made for the placement of a cholecystotomy tube. Fortunately, an EUS also was requested and showed an obvious gallbladder cancer. The cholecystomy tube was not placed.

EUS typically uses higher scanning frequencies than transcutaneous abdominal ultrasound (5–10 vs. 2–5 MHz) and can visualize the gallbladder from a closer distance (from the antrum or duodenal bulb), providing more detailed views of gallbladder abnormalities, including a double-layer wall ultrasound pattern [4]. A gallbladder wall thicker than 10 mm, disruption of the normal two layers of the gallbladder wall, hypoechoic internal echogenicity, and the absence of gallstones were found to correlate with gallbladder neoplasia [4].

Intramural cysts of the gallbladder are rare; according to one case report only 13 cases have been reported in the world literature up to 2002 [4]. Here we present is an elderly patient who was sent to us for EUS evaluation of a dilated main pancreatic duct. The pancreas was otherwise normal. The cystic lesion in the gallbladder was incidentally found. The EUS clearly shows the epithelial origin of the cyst.

Courvoisier’s law states that in the presence of a palpable gallbladder, jaundice is unlikely to be caused by gallstones. However, Courvoisier was not quite as dogmatic. Here is what he actually wrote in his Treatise on the Pathology and Surgery of the Biliary Passages (translated from the German) [5]:

Obstruction by stone is supported by

1.

prior (self-limited) jaundice attacks

 

2.

continuing but fluctuating jaundice

 

3.

jaundice present for years

 

4.

prior typical biliary colic attacks, especially if they were associated with jaundice

 

5.

previous passage of gallstones

 

6.

no or only mild distention of the gallbladder

 

7.

fever with more or less intermittent character

 

Obstructions of other types are indicated by the lack of these characteristics and most importantly by the presence and considerable size of a distended gallbladder [5].

This is a 61-year-old patient with obstructive jaundice secondary to cancer of the pancreatic head who has a very dilated gallbladder.

The function of the spiral mucosal folds seen in the cystic duct are unknown. The duct and spiral folds contain muscle fibers that apparently respond to a variety of stimuli but there is no discrete muscular sphincter. It is speculated that the spiral valves are mechanical devices that keep the tortuous cystic duct patent. During endosonography the Heister valves can sometimes be demonstrated.

This is a 40-year-old woman with a symptomatic subhepatic cyst initially believed to be a choledochalcyst. The size of the cyst increased significantly over the course of 2 years and the patient eventually became deeply jaundiced. A preoperative CT scan surprisingly showed no connection to the biliary system, but the cyst caused extrinsic compression of the biliary tree. The excised cyst was lined by a squamous epithelium, an unusual feature, but contained no malignancy. Choledochal cysts are lined by a biliary-type epithelium but often have focal or extensive squamous metaplasia in response to chronic inflammation. The exact taxonomy of this cyst remains unclear but is does not appear to derive from the biliary tree. There are several reviews about common presentations, diagnostic methods, and treatment of congenital and acquired liver cysts [6, 7].

Typical ultrasound features of hepatic hemangiomas are their small size, uniform hyperechogenicity, well-defined margins, and posterior echo enhancement. These typical characteristics are modified as the hemangioma grows larger.

Not all hemangiomas are hyperechoic. In one recent large series, hepatic hemangiomas diagnosed with contrast-enhanced CT were classified by internal echo pattern as homogeneous hyperechoic (35.0 %), homogeneous hypoechoic (22.9 %), isoechoic (5.2 %), mixed hyperechoic (22.1 %), or mixed hypoechoic (14.8 %) [8].

Hepatomas, especially small ones, are difficult to diagnose or biopsy. Obviously, some segments of the liver are not accessible by EUS. Nevertheless, EUS should be considered when the lesions are within the reach of the echoendoscope. The valuable role EUS can play in the detection and biopsy of small hepatomas that are not well visualized or would be difficult to access by percutaneous ultrasound is increasingly being recognized [9]. According to published retrospective series, EUS-guided FNA provides adequate tissue for diagnosis and with minimal risk of complications [10]. Moreover, metastatic lesions, especially to lymph nodes, can also easily be biopsied as this next case and others show [11]. This patient is a 51-year-old man with a history of chronic liver disease who had increasing alpha-fetoprotein levels and large bilateral adrenal masses without known liver lesions. An initial EUS-guided fine-needle aspiration (FNA) could not be completed because of problems during sedation. The study did, however, show liver lesions suspicious for hepatoma that were not previously recognized by CT. Magnetic resonance imaging also demonstrated the lesions seen during EUS. During a subsequent EUS with anesthesia support, FNA biopsies or aspirates were obtained from two liver lesions (showing hepatoma), ascites (negative), the left adrenal lymph node (benign), and two small perigastric lymph nodes (metastatic hepatoma).