**3. Clinical manifestations**

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

#### **3.1. Complications**

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 its functional disturbance with consecutive gallstones.

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 malignant cells.

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 of malignant degeneration.

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.

The rupture of serous hepatic cyst is a rare complication that needs emergency intervention. The cyst rupture is generally secondary to trauma, but a spontaneous one is also possible. The cyst fluid can enter the pleural or peritoneal cavity, causing pain in right upper quadrant or even diffuse abdominal pain due to peritoneal irritation.

Granuloma degeneration is a rare complication of the hepatic cysts (Figure 10). In severe form, it can resemble malignant invasion into surrounding tissues. The differential diagnosis is difficult to make even intraoperatively. Extensive excision of involved tissues is sometimes necessary [28]. Eventually histology delineates the diagnosis.

**Figure 10.** Serous cyst with granulomatous transformation, hyaline collagen fibrosis and focal, nonspecific chronic in‐ flammation. Hematoxylin and eosin staining ×100.
