Background

Nonparasitic hepatic cysts (NPHCs) are the most common diseases of the liver. Most patients with NPHC are asymptomatic and do not require treatment, while those with large cysts might be symptomatic and require treatment. Spontaneous rupture of hemorrhagic NPHC is extremely rare. There is no standard recommended treatment for a ruptured hemorrhagic NPHC. Herein, we report two rare cases in which laparoscopic deroofing was performed to treat spontaneous rupture of a hemorrhagic NPHC.

Case presentation

Case 1

An 85-year-old man who had been followed up for a simple hepatic cyst (89 × 85 mm) for 2 years was referred for sudden-onset right hypochondralgia and fever. He had no history of previous surgery and was a known case of hypertension. The patient was not on anticoagulants. The onset of pain was spontaneous, and there was tenderness in the right upper quadrant without guarding; there was no history of trauma. Laboratory test results revealed mild anemia (Table 1).

Table 1 Blood examination on arrival
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Computed tomography (CT) showed a simple hepatic cyst 13 cm in diameter, occupying the right lobe of the liver. The cystic wall was not smooth but serrated. The Hounsfield Unit level was 40 at the lower level of the cyst and less than 10 at the upper level. Fluid collection was observed on the liver surface (Fig. 1). These findings indicated a ruptured cyst and intracystic hemorrhage. Following the diagnosis and considering stable vital signs and no symptoms of peritonitis, a semi-urgent elective surgery was scheduled. However, the hemoglobin level rapidly decreased from 13.1 g/dL to 11.2 g/dL on the following day. Therefore, urgent laparoscopic intervention was performed.

Fig. 1
figure 1

Enhanced CT of case 1. A CT demonstrated a simple hepatic cyst occupying the right lobe of the liver, and fluid collection on the surface of the liver (arrow). B The Hounsfield Unit level was 40 at the lower level of the cyst (arrowhead). C A part of the cystic wall was not smooth but serrated (dotted arrow)

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Abundant hemoperitoneum and a voluminous hepatic cyst occupying the right lobe were observed through laparoscopy. The anterior wall of the cyst was deroofed and resected (Fig. 2). Approximately 1 L of partially coagulated blood was removed. After evacuation, continuous oozing which might be venous was found at the posterior wall of the cyst, and hemostasis was confirmed after cauterization. Results of the laboratory tests of the cystic fluid showed a normal level of total bilirubin. No bacteria or malignant cells were identified in the cystic fluid. Pathological investigation revealed no evidence of malignancy or Echinococcus species infection. The postoperative course was uneventful, and the patient was discharged on postoperative day 6.

Fig. 2
figure 2

Intraoperative findings of case 1. A Surgical exploration revealed hemoperitoneum (arrow) and a voluminous hepatic cyst, occupying the right lobe. B Continuous oozing was found at the posterior wall of the cyst (arrow heads)

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Case 2

A 72-year-old woman, who had been followed up for a simple hepatic cyst (13 cm) for 3 years was referred for sudden onset of right hypochondralgia. She had previously undergone partial mastectomy and was treated for hypertension and hyperlipidemia. She had no history of anticoagulant drug intake or trauma. The onset of pain was spontaneous and there was tenderness in the right upper quadrant, with no guarding. Results of the laboratory tests revealed elevated WBC and CRP levels (Table 2).

Table 2 Blood examination on arrival
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CT demonstrated a simple hepatic cyst 9.9 cm in diameter occupying segment 4 of the liver. Fluid accumulation was seen between the spleen and abdominal wall (Fig. 3); the diagnosis was a ruptured cyst. Following the diagnosis, stable vital signs, and no symptoms of peritonitis, a semi-urgent surgery was scheduled.

Fig. 3
figure 3

Enhanced CT of case 2. A CT demonstrated a simple hepatic cyst (13 cm) in segment 4 previously. B CT showed ruptured cyst (9.9 cm) and fluid collection between the spleen and the abdominal wall

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Two days later, laparoscopic deroofing was performed. Hemoperitoneum and a hepatic cyst occupying segment 4 of the liver were observed through the laparoscope. The anterior wall of the cyst was deroofed and resected. Approximately 470 mL of partially coagulated blood was removed. After evacuation, continuous oozing which might be venous was observed at the posterior wall of the cyst, and hemostasis was confirmed after cauterization. Results of the laboratory tests of the cystic fluid showed a normal level of total bilirubin. No bacteria or malignant cells were identified in the cystic fluid. Pathological investigation revealed no evidence of malignancy or infection. The postoperative course was uneventful, and the patient was discharged on postoperative day 6.

Discussion

Intrahepatic cysts are generally classified as congenital, traumatic, inflammatory, parasitic, or neoplastic [1]. NPHC is the most common disease of the liver and is found in approximately 1–5% of the general population [2]. The female-to-male ratio is 3:1. Most patients with NPHC are asymptomatic and do not require treatment. However, patients with symptoms, such as appetite loss due to compression of adjacent structures, abdominal pain, intracystic infection, jaundice, cyst–biliary communication, and rupture, which require treatment [3].

Although rupture of hepatic cysts is sometimes seen in cases of infection with Echinococcus species, spontaneous rupture of a hemorrhagic NPHC is extremely rare [4]. A search of English-language reports published in PubMed using the keywords ‘liver’, ‘hepatic’, ‘cyst’, ‘rupture’, ‘spontaneously’, and ‘hemorrhage’ from 1999 to 2021 returned only 14 cases that described spontaneous rupture of hemorrhagic NPHC, including our cases (Table 3) [5,6,7,8,9,10,11,12,13,14,15,16]. Since the cystic lesions of autosomal dominant polycystic kidney disease (ADPKD) have different pathogeneses, patients with ADPKD were excluded from the results of our keyword search. There were no differences between the sexes. Eleven patients were more than 60 years old. The chief complaints of 11 patients were abdominal pain, and four of them had peritonitis. Twelve patients had sudden-onset pain, including chest pain. The diameter of the cyst exceeded 10 cm in 12 patients. The final diagnoses were simple hepatic cysts in nine cases, biliary cysts in three cases, and bacterial infection in one case. In cases with sudden-onset pain during follow-up of an NPHC larger than 10 cm, rupture of a hemorrhagic hepatic cyst should be suspected.

Table 3 Summary of patients with spontaneously ruptured hemorrhagic hepatic cyst
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Takahashi et al. reported that an increase in intracystic pressure induces necrosis in the cyst wall and consequent intracystic bleeding and rupture [17]. An increase in intracystic pressure might be related to the secretion of the cystic epithelium, exudation due to an infection, or intracystic bleeding. A fragile cyst wall due to invasion of cancer could also increase the risk of spontaneous rupture.

There is no standard strategy for the management of ruptured hemorrhagic NPHC. In general, the therapeutic options include surgical procedures and non-surgical procedures, such as transcatheter arterial embolization (TAE), percutaneous drainage, and sclerotherapy. Non-surgical management might be a useful option for patients with stable vital signs. However, high recurrence rates have been reported after non-surgical treatment in patients with symptomatic hepatic cysts [6, 18, 19]. In recent times, a laparoscopic approach has been proposed and is considered as a minimally invasive treatment. In our review, of the ten patients who underwent surgical treatment, three were treated using laparoscopy. Patients who underwent laparoscopic treatment were discharged earlier than those treated with other modalities and had no recurrence. Recurrence was observed in only one patient who underwent TAE and percutaneous drainage. While HCC is fed with the artery and TAE is effective for the ruptured HCC, a hemorrhagic hepatic cyst is caused by the damage of the cystic wall and bleeding is peripheral. It might be the reason why TAE was not effective.

In our review, 12 of 14 cases, including our case, had sudden-onset pain. Furthermore, two of them developed hemorrhagic shock and were in a life-threatening condition. Sudden-onset pain in patients with a history of hepatic cysts could be an indicator of a ruptured hemorrhagic cyst. These patients require imaging studies, including ultrasonography and CT. Dynamic CT with contrast agent is very useful to diagnose hemorrhage by showing the extravasation. However, in cases of hemorrhagic hepatic cysts, bleeding is not so active and not from the artery or the portal vein, but from the peripheral vein of the cystic wall. Thus, dynamic CT could not show the extravasation from the cystic wall in our cases. Emergency surgery should be considered in patients with unstable vital signs or peritonitis. In addition, we suggest that in patients with a decrease in hemoglobin concentration, such as in case 1, urgent surgery should be considered even when vital signs are stable. Elective surgery might be appropriate for patients without unstable vital signs, peritonitis, or progressive decrease in hemoglobin.

Conclusion

Spontaneous rupture of a hemorrhagic NPHC is extremely rare. Laparoscopic deroofing was successfully performed in patients with spontaneous rupture of hemorrhagic NPHC.