**4. Diagnosis**

**3. Clinical manifestations**

258 Recent Advances in Liver Diseases and Surgery

**3.1. Complications**

malignant cells.

of malignant degeneration.

they are large, fast growing, multiple, or complicated.

its functional disturbance with consecutive gallstones.

Generally, patients with nonparasitic hepatic cysts less than 3 cm are asymptomatic [2]. Cysts are classified as "large" when they are greater than 4 cm in the longest diameter. If the diagnosis of hepatic serous cyst is clear, there is no need of treatment, unless it becomes symptomatic, has a diameter more than 5 cm, or if the cyst grows rapidly within a short period of time [19].

Around 15% of patients with liver cysts develop symptoms at some stage in life. When the patients start complaining, the most common symptom is pain in the right upper quadrant. Other encountered symptoms are nausea, vomiting, abdominal meteorism, shoulder or lumbar pain, dyspnea, and/or postprandial fullness. Hepatic cysts become symptomatic when

Complications occur in approximately 10% of patients [20]. Obstructive jaundice, portal hypertension, intracystic hemorrhage, infection, intraperitoneal and/or intrahepatic rupture, torsion, and inflammation represent complications of nonparasitic hepatic cysts [21–24]. The compression exerted by a large hepatic cyst on the adjacent structures can manifest as cardiac arrhythmia or inferior vena cava thrombosis [25, 26]. The vicinity with the cholecyst can cause

Hemorrhage into a simple liver cyst is rather uncommon but poses issues regarding differential diagnosis. The differential diagnosis between intracystic hemorrhage, cystadenoma, and cystadenocarcinoma is difficult with the imaging studies currently available. One consequence is to assume a simple cyst with intracystic hemorrhage as being neoplastic lesion and perform an unnecessary hepatectomy. The other consequence is to assume a neoplastic lesion as being benign and perform laparoscopic fenestration with subsequent peritoneal dissemination of

There are situations when an intracystic hemorrhage occurs unrecognized. Even if no acute symptoms supervene, the hemorrhage causes a rapid enlargement of the cyst, raising suspicion

Infection of hepatic cyst can occur through common bile duct or blood stream. The most common encountered microorganisms are *Escherichia coli* and *Klebsiella pneumoniae*. *Proteus*, *Bacteroides*, and *Clostridium* are also incriminated in infection of hepatic cysts. The most likely source of infection for simple liver cysts is the gastrointestinal tract. Diverticulitis of the sigmoid colon and gut manipulation during abdominal operations have been found to be the cause of infectious complications of hepatic cysts [27]. The patients with diabetes mellitus, undergoing chronic hemodialysis or immunosuppressive therapy (e.g., after kidney transplant in patient with polycystic liver and kidney disease), are prone to develop such infections.

The patient with infected liver cyst presents with acute onset of right upper quadrant abdomi‐ nal pain, diarrhea, and/or fever. There are situations when pain is absent, and the only symptoms are fever and malaise that render a complete workup to rule out other causes.

Percutaneous abdominal ultrasonography (US) is the best imaging modality for diagnosis of serous hepatic cysts. US is generally the first choice diagnostic procedure because it is sensitive, specific, noninvasive, and ready available. The typical appearance of simple cyst on US is as follows: round or oval anechoic mass, well circumscribed, with thin and smooth borders or indiscernible walls, strong posterior echo enhancement, without mural vegetations, calcifica‐ tions, or septations (Table 1).

Although US can offer reliable data regarding relations of the hepatic cysts to the vascular and biliary tree, the standard diagnostic protocol in our clinic includes CT with i.v. contrast substance. MRI is also useful to establish a correct diagnosis (Algorithm 1) [29].

Intraoperative use of an ultrasound probe, where the abdominal wall thickness is not an issue, allows the placement of a higher MHz ultrasound transducer directly on the liver surface. Therefore, intraoperative ultrasound images are much sharper and well defined than those obtained through a transabdominal approach. Intraoperative US not only confirms the diagnosis but also adds important information to define the relation between the cysts and the surrounding structures (portal and hepatic veins, inferior vena cava, bile ducts), especially in deeply located cysts. Intraoperative US is also used to guide the surgeon for cyst approach in case no capsular expression is found. For laparoscopy, specially designed ultrasound probe and software are necessary.


**Table 1.** Ultrasonographic features for the diagnosis of monocystic diseases of the liver

CT and MRI can resolve the diagnosis of the doubtful cases and provide more information on the location of the cyst and relations with the great vessels and biliary tree. Thus, CT and/or MRI are mandatory for an appropriate treatment planning. US, CT, and MRI are complemen‐ tary in evaluation of hepatic cysts. Based on imagistic examinations, parasitic cysts, neoplastic degeneration, and complications must be ruled out before pursuing any therapy decision.

On CT scan, simple hepatic cysts are well-defined, space occupying, round or oval-shaped, thin-walled, homogenous masses, with a density close to water (0–5 Hounsfield) and modest enhancement after contrast injection.

The presence of septa is not a common feature of the simple cyst, but multiple contiguous cysts can simulate it. For countries where hydatid disease is endemic, the differential diagnosis must include it because it is essential for therapeutic decision making.

The injection of intravenous contrast allows the manifestation of a possible communication between the cyst and the biliary tree on CT and MRI [29]. The communication of the hepatic cyst with the bile ducts can also be visualized using cystography, intraoperative cholangiog‐ raphy, and ERCP.

The mural calcifications are nonspecific but are usually present in echinococcal cysts and malignant lesions.

MRI provides valuable information concerning the nature of the cyst content and helps differentiating between blood and mucin [12]. MRI can identify a hypointense pseudocapsule characteristic of the echinococcal cyst. MRI, especially associated with MRCP, is helpful for the diagnosis of biliary cysts, localized Caroli disease (Figure 4), intrahepatic biliary cystade‐ noma, and cystadenocarcinoma.

obtained through a transabdominal approach. Intraoperative US not only confirms the diagnosis but also adds important information to define the relation between the cysts and the surrounding structures (portal and hepatic veins, inferior vena cava, bile ducts), especially in deeply located cysts. Intraoperative US is also used to guide the surgeon for cyst approach in case no capsular expression is found. For laparoscopy, specially designed ultrasound probe

**echinococcosis**

centre

Appearance No septa Multiseptated Multivesicular Septations and/or papillary

CT and MRI can resolve the diagnosis of the doubtful cases and provide more information on the location of the cyst and relations with the great vessels and biliary tree. Thus, CT and/or MRI are mandatory for an appropriate treatment planning. US, CT, and MRI are complemen‐ tary in evaluation of hepatic cysts. Based on imagistic examinations, parasitic cysts, neoplastic degeneration, and complications must be ruled out before pursuing any therapy decision. On CT scan, simple hepatic cysts are well-defined, space occupying, round or oval-shaped, thin-walled, homogenous masses, with a density close to water (0–5 Hounsfield) and modest

The presence of septa is not a common feature of the simple cyst, but multiple contiguous cysts can simulate it. For countries where hydatid disease is endemic, the differential diagnosis must

The injection of intravenous contrast allows the manifestation of a possible communication between the cyst and the biliary tree on CT and MRI [29]. The communication of the hepatic cyst with the bile ducts can also be visualized using cystography, intraoperative cholangiog‐

The mural calcifications are nonspecific but are usually present in echinococcal cysts and

MRI provides valuable information concerning the nature of the cyst content and helps differentiating between blood and mucin [12]. MRI can identify a hypointense pseudocapsule

ring and hypoechogenic

Dorsal shadowing (calcified areas)

**Cystadenoma and cystadenocarcinoma**

Hypoechogenic, with hyperechogenic floating material, fluid–fluid sedimentation

Dorsal shadowing (calcified

projections

areas)

**Simple cyst Cystic echinococcosis Alveolar**

Echo pattern Anechoic Anechoic or atypical Hyperechogenic outer

**Table 1.** Ultrasonographic features for the diagnosis of monocystic diseases of the liver

include it because it is essential for therapeutic decision making.

Relative accentuation

of echoes

enhancement after contrast injection.

Border Sharp and smooth Laminated, thick Irregular Irregular Shape Spherical or oval Round or oval Irregular Round or oval

> Dorsal shadowing (calcified areas)

and software are necessary.

260 Recent Advances in Liver Diseases and Surgery

Posterior acoustic

raphy, and ERCP.

malignant lesions.

feature

A liver cyst with intracystic hemorrhage appears as a heterogeneous echogenic cyst on US. For improved US imaging, an ultrasound contrast substance (e.g., Levovist, Bayer Australia Limited; SonoVue, Bracco International B.V.) can be used. The procedure is known as contrastenhanced ultrasound (CEUS) and uses a microbubble agent that produces multiple small (approximately 3 μm) stabilized air bubbles when suspended in water. After intravenous injection of Levovist, Doppler enhancement of the blood pool is observed for 2–5 min, followed by a late hepatosplenic phase that lasts for more than 30 min. If no enhancement of the intracystic structures but an enhanced smooth cyst wall is observed on Levovist US, then an intracystic clot is suspected. On plain CT, the hemorrhagic cyst appears heterogeneous lowdensity (Figure 11). On MRI, T1-weighted images reveal the clot as low intensity and the fluid as high intensity, whereas T2-weighted images show the clot as low intensity and the fluid as high intensity [30].

**Figure 11.** CT, axial view: multiple hepatic cysts, the largest cyst, located in segment VI–VII is ruptured in hepatic pa‐ renchyma; intracystic hematoma and extensive subcapsular hematoma are visible on the right hepatic lobe. (A, C) Na‐ tive examination; (B,D) Examination with i.v. contrast administration.

the intracystic mural protrusions, then malignancy is highly considered.

On US, the differential diagnosis between intracystic hemorrhage and neoplastic degeneration may be challenging when intracystic parietal protrusions are identified (Figure 12). If no Doppler signal exists, these protrusions may be interpreted as sedimentations of hematin on the cyst wall. On macroscopic examination during operation, these protrusions have the equivalent of the blackish-brown deposits that stain the cyst wall. If Doppler signal is certified in the intracystic mural protrusions, then malignancy is highly considered. intracystic hematoma and extensive subcapsular hematoma are visible on the right hepatic lobe. (A, C) Native examination; (B, D) with i.v. contrast administration. On US, the differential diagnosis between intracystic hemorrhage and neoplastic degeneration may be challenging when intracystic parietal protrusions are identified (Figure 12). If no Doppler signal exists, these protrusions may be interpreted as sedimentations of hematin on the cyst wall. On macroscopic examination during operation, these protrusions have the equivalent of the blackish‐brown deposits that stain the cyst wall. If Doppler signal is certified in

**Figure 11.** CT, axial view: multiple hepatic cysts, the largest cyst, located in segment VI–VII is ruptured in hepatic parenchyma;

border, without calcifications, but with small hyperechoic parietal protrusions that do not change with patient's position. On Doppler examination, these protrusions are avascular and on CT are not visible. The intraoperative and histological diagnosis was serous hepatic cyst with hemorrhagic content. Cystadenocarcinoma had to be ruled out. Patient was submitted to open surgery. **Figure 12.** Transabdominal US for a cystic mass in the liver: the mass is anechoic, homogenous, with thin border, with‐ out calcifications, but with small hyperechoic parietal protrusions that do not change with patient's position. On Dop‐ pler examination, these protrusions are avascular and on CT are not visible. The intraoperative and histological diagnosis was serous hepatic cyst with hemorrhagic content. Cystadenocarcinoma had to be ruled out. Patient was submitted to open surgery.

**Figure 12.** Transabdominal US for a cystic mass in the liver: the mass is anechoic, homogenous, with thin

Gallium scintigraphic study can be used to search for the site of infection in a patient with a previous diagnosis of simple hepatic cyst [27]. 18‐F‐fluorodeoxyglucose is useful for the detection of cyst infection using positron emission tomography in patients with multiple liver and renal cysts [31]. In a patient diagnosed with hepatic cyst, any febrile status should raise the question of its possible infectious complication. In case of cyst rupture, on imaging scans, irregularities of the partially evacuated cyst wall, heterogeneous content, fluid Gallium scintigraphic study can be used to search for the site of infection in a patient with a previous diagnosis of simple hepatic cyst [27]. 18-F-fluorodeoxyglucose is helpful for the detection of cyst infection using positron emission tomography in patients with multiple liver and renal cysts [31]. In a patient diagnosed with hepatic cyst, any febrile status should raise the question of its possible infectious complication.

under the liver capsule, or free liquid in the peritoneal or pleural cavity are depicted. Nonparasitic hepatic cysts may coexist with other hepatic lesions, bringing out the issue of correlation the lesion with the patient's symptoms and also of adopting the right management decision. In case of cyst rupture, on imaging scans, irregularities of the partially evacuated cyst wall, heterogeneous content, fluid under the liver capsule, or free liquid in the peritoneal or pleural cavity are depicted.

> Nonparasitic hepatic cysts may coexist with other hepatic lesions, bringing out the issue of correlation the lesion with the patient's symptoms and also of adopting the right management decision.

> 9 Nonparasitic cysts may coexist with parasitic ones (Figure 13). Even if the size of nonparasitic cyst does not justify its fenestration, it is recommended to solve both types of cysts in the same operation in order to avoid future misdiagnosis between the nonparasitic and parasitic cyst.

> Nonparasitic hepatic cysts may coexist with other benign or malignant liver tumors. When a benign tumor lesion (e.g., hepatic hemangioma) is diagnosed besides hepatic cyst, there is an issue regarding which lesion should be treated to elevate the pain in the right upper quadrant (Figure 14).

#### 262 Recent Advances in Liver Diseases and Surgery Diagnostic and Therapeutic Challenges in Nonparasitic Liver Cysts http://dx.doi.org/10.5772/61057 263

On US, the differential diagnosis between intracystic hemorrhage and neoplastic degeneration may be challenging when intracystic parietal protrusions are identified (Figure 12). If no Doppler signal exists, these protrusions may be interpreted as sedimentations of hematin on the cyst wall. On macroscopic examination during operation, these protrusions have the equivalent of the blackish-brown deposits that stain the cyst wall. If Doppler signal is certified

On US, the differential diagnosis between intracystic hemorrhage and neoplastic degeneration may be challenging when intracystic parietal protrusions are identified (Figure 12). If no Doppler signal exists, these protrusions may be interpreted as sedimentations of hematin on the cyst wall. On macroscopic examination during operation, these protrusions have the equivalent of the blackish‐brown deposits that stain the cyst wall. If Doppler signal is certified in

> **Figure 12.** Transabdominal US for a cystic mass in the liver: the mass is anechoic, homogenous, with thin border, without calcifications, but with small hyperechoic parietal protrusions that do not change with patient's position. On Doppler examination, these protrusions are avascular and on CT are not visible. The intraoperative and histological diagnosis was serous hepatic cyst with hemorrhagic content.

> **Figure 12.** Transabdominal US for a cystic mass in the liver: the mass is anechoic, homogenous, with thin border, with‐ out calcifications, but with small hyperechoic parietal protrusions that do not change with patient's position. On Dop‐ pler examination, these protrusions are avascular and on CT are not visible. The intraoperative and histological diagnosis was serous hepatic cyst with hemorrhagic content. Cystadenocarcinoma had to be ruled out. Patient was

Gallium scintigraphic study can be used to search for the site of infection in a patient with a previous diagnosis of simple hepatic cyst [27]. 18‐F‐fluorodeoxyglucose is useful for the detection of cyst infection using positron emission tomography in patients with multiple liver and renal cysts [31]. In a patient diagnosed with hepatic cyst, any febrile

Gallium scintigraphic study can be used to search for the site of infection in a patient with a previous diagnosis of simple hepatic cyst [27]. 18-F-fluorodeoxyglucose is helpful for the detection of cyst infection using positron emission tomography in patients with multiple liver and renal cysts [31]. In a patient diagnosed with hepatic cyst, any febrile status should raise

In case of cyst rupture, on imaging scans, irregularities of the partially evacuated cyst wall, heterogeneous content, fluid

In case of cyst rupture, on imaging scans, irregularities of the partially evacuated cyst wall, heterogeneous content, fluid under the liver capsule, or free liquid in the peritoneal or pleural

Nonparasitic hepatic cysts may coexist with other hepatic lesions, bringing out the issue of correlation the lesion with the

Nonparasitic hepatic cysts may coexist with other hepatic lesions, bringing out the issue of correlation the lesion with the patient's symptoms and also of adopting the right management

**Figure 11.** CT, axial view: multiple hepatic cysts, the largest cyst, located in segment VI–VII is ruptured in hepatic parenchyma; intracystic hematoma and extensive subcapsular hematoma are visible on the right hepatic lobe. (A, C) Native examination; (B, D) with

9

Nonparasitic cysts may coexist with parasitic ones (Figure 13). Even if the size of nonparasitic cyst does not justify its fenestration, it is recommended to solve both types of cysts in the same operation in order to avoid future misdiagnosis between the nonparasitic and parasitic cyst.

Nonparasitic hepatic cysts may coexist with other benign or malignant liver tumors. When a benign tumor lesion (e.g., hepatic hemangioma) is diagnosed besides hepatic cyst, there is an issue regarding which lesion should be treated to elevate the pain in the right upper quadrant

in the intracystic mural protrusions, then malignancy is highly considered.

Cystadenocarcinoma had to be ruled out. Patient was submitted to open surgery.

the intracystic mural protrusions, then malignancy is highly considered.

status should raise the question of its possible infectious complication.

the question of its possible infectious complication.

submitted to open surgery.

cavity are depicted.

decision.

(Figure 14).

patient's symptoms and also of adopting the right management decision.

under the liver capsule, or free liquid in the peritoneal or pleural cavity are depicted.

i.v. contrast administration.

**Figure 13.** CT, axial view: voluminous hydatid cyst in the right hepatic lobe and small cyst mass in segment II-III. (A) Native; (B) after administration of i.v. contrast.

**Figure 14.** CT showing coexistence of two hepatic lesions: central simple hepatic cyst, in close proximity with gallblad‐ der, and hepatic hemangioma in segment VI. (A) Axial view, native; (B) axial view, after i.v. contrast, arterial phase; (C) sagittal view, after i.v. contrast, arterial phase. Patient was submitted to laparoscopic fenestration of the hepatic cyst. The operation was successful in abolishing the right quadrant pain.

Nonparasitic cysts can also coexist with peripheral cholangiocarcinoma. The association was found in patients with PLD after kidney transplantation. The presence of liver metastasis from colorectal cancer was also found in patients with PLD (Figure 15).

**Figure 15.** CT, axial view, with (A) and without (B) i.v. contrast showing coexistence of a bulk solid liver metastasis from colonic cancer in a patient with previously known PLD.

Serological tests for *Echinococcus* are electrosyneresis, hemagglutination, and ELISA (enzymelinked immunosorbent assay) (the latter two being quantitative) [32]. The specific serology for *Echinococcus* has a sensitivity of 80% in the diagnostic process of parasitic cysts.

Serum tumor markers (e.g., CA 19-9 and CEA) must be checked to rule out neoplasia.

Right upper pain requires workup to exclude other associated pathology that may be the only or in addition responsible for causing the symptoms. Thus the surgeon should rule out cholelithiasis, gastroesophageal reflux disease, peptic ulcer disease, acute gastritis, or color‐ ectal cancer. Upper and lower gastrointestinal endoscopy can reveal such pathologies and help avoiding misdiagnosis and mistreatment based solely on the pain supposedly caused by the hepatic cyst.
