Simple cysts with a twist!
1Fifth year Medicine, School of Medicine, Trinity College Dublin
A 40-year-old woman presented to the emergency department in March 2015 complaining of a one-week history of worsening right upper quadrant (RUQ) abdominal pain. The patient described the pain as being constant in nature with no radiation and reported that rest and paracetamol helped alleviate it. She denied the presence of any fever, chills, jaundice, changes in bowel habits, recent illness, and sick contacts. Additionally, the patient was not taking any regular medications, had no known drug allergies, and was a non-smoker and non-drinker. Her past medical history included malaria in 1997 and a prior diagnosis of multiple benign liver cysts in 2010. She was seen that year by the Hepato-Pancreato-Biliary (HPB) surgical sub-specialty team at the same hospital as this presentation, following an episode of RUQ pain. Imaging scans were completed which showed evidence of what were thought to be three cystic lesions of different dimensions. The HPB team reassured her that these lesions appeared benign in nature and that the pain may have been caused by a small haemorrhage into one of the cysts. As such, the patient was told to return to the clinic if further symptoms developed, but that there was currently no indication for surgical management.
At the time of presentation to the emergency department in 2015, the patient was afebrile, with a pulse rate of 82 beats per minute, and a blood pressure of 100/64 mmHg. On physical examination, she had a soft and non-tender abdomen, with an easily palpable mass present in the RUQ.
Investigations and Diagnosis
The patient underwent a computed tomography (CT) scan of the abdomen and pelvis while in the emergency department. It was compared to the CT and MRI images taken in 2010 (Figure 1). The most recent CT revealed three cystic lesions in the right hepatic lobe as previously visualised, with interval enlargement of the cysts in segment 5/6 and 7/8 (Figure 2). The cyst in segment 7/8 now showed hyper-attenuating debris that was layering dependently. The third cyst in segment 6 was smaller in size and had peripheral calcification. There were no new lesions present, and no enhancing internal septations or worrisome mural nodularity, which would have been significant for malignancy. It was concluded that the new internal debris in the segment 7/8 cyst might represent an internal haemorrhage. Therefore, the patient’s diagnosis remained the same as multiple simple liver cysts, and she was discharged home with a referral sent for an outpatient HPB follow-up appointment.
The patient was seen in the HPB clinic in May 2015. The patient is from the Middle East where she lived on her family’s farm and grew up around sheep, but she has lived in Canada for the past 18 years during which time she has made a few return trips. She had experienced intermittent RUQ pain since her appointment in 2010, but the pain was significantly worse when she attended the emergency department this past March. Her recent imaging was reviewed, and a review of systems was unremarkable. Of note, serology from her initial consultation in 2010 had revealed a ‘low positive’ status for Echinococcus. On exam, the patient was a thin lady with a non-tender abdomen and a definite mass in the RUQ.
The HPB team concluded that these recurrent episodes of RUQ abdominal pain were related to repeated haemorrhages into the cyst, and due to the persistence of the pain, they offered the patient surgical management. Following a review of her imaging which did not suggest the presence of hydatid liver disease, she consented for a laparoscopic unroofing of the cysts.
The patient was brought to the operating room in July of 2015, and the case began following standard surgical protocol. Upon gross visualisation of the abdomen following diagnostic laparoscopy, two large cysts were seen on the liver, both with a thick wall and a whitish appearance in colour. The inferior cyst was more visible as the superior one had inflammatory adhesions connecting it to the anterior diaphragm. The overall appearance was suggestive of simple cysts, and the surgery continued as usual for a laparoscopic cyst marsupialization. The inferior cyst was punctured anteriorly and inferiorly by a gynaecologic cyst aspirator needle and connected to suction. No fluid was collected through the suction system, and instead, thick yellow pus-like fluid oozed out around the site where the needle had entered alerting the team that a change of strategy was required. A standard suction method was successfully commenced, but small transparent spherical beads were seen in the proximity of the needle opening. A larger suction was applied to minimise the risk of any spillage of cyst contents. The cyst continued to be difficult to aspirate, and consequently, a larger opening was made in it to allow for better suctioning. On visualisation, the internal contents of the cyst contained many transparent spherical beads of varying diameters, and thick white membranous structures suspended in the fluid. The anaesthesiologist was immediately alerted to the possibility of a hydatid cyst, and the concern that an anaphylactic reaction and its associated hemodynamic changes following patient exposure to the spilt cyst contents. No such adverse event occurred and active spillage was halted, allowing for an immediate intra-operative team discussion and review of the case, along with an intra-operative consultation with a second HPB surgeon. A decision was made to remove a small part of the cyst wall and refer it to pathology for frozen section to verify the diagnosis. The report confirmed hydatid cyst disease.
The patient’s serology and 2010 radiology were reviewed (Figure 1). Although the MRI report suggested that both large cysts represented simple cysts, it did report on a smaller third cyst which was not visually present at the time of surgery, but a hydatid cyst had been given as its differential. The 2015 CT scan was reviewed, and given the current surgical presentation, the internal debris in the superior cyst that was thought to be due to cyst haemorrhage could, in fact, have been membranes inside the cyst as seen intra-operatively (Figure 2).
The procedure was converted to an open resection of the hydatid cysts in liver segments 6 and 7 (Figure 3). Both cysts were completely evacuated by D&C suction and were 80% resected. The residual medial walls of the cysts and liver surface were ablated using argon and cautery. Adequate mobilisation of the liver was achieved before beginning the transection of the posterior liver. The remaining cyst contents were completely aspirated without additional spillage. All remaining small bead daughter cysts were carefully and successfully removed. The fluid from the superior cyst was sent for bacteriology. A mixture of iodine and saline was infused into the inferior cyst for ten minutes before its resection, and 20% hypertonic saline was instilled into the superior cyst following its evacuation. A hypertonic saline solution was also applied to the retroperitoneum, the anterior wall of the diaphragm, and Gerota’s fascia, along with saline-soaked laparotomy pads prior to closing. Sufficient time was given to soak the area, aspirate the hypertonic saline and remove the laparotomy pads. The entire surgical field was fastidiously inspected for any remaining daughter cysts. Finally, omentum was generously placed over the residual medial cyst walls. A JP drain and intercostal nerve block were inserted, and the fascia was closed with sutures and staples. General anaesthesia was reversed, and the patient was transferred to the recovery room in a stable condition.
Outcome and Follow-up
The patient recovered well in hospital post-operatively. As an inpatient, she was seen by the Infectious Disease team and prescribed a one-month course of albendazole. She was discharged home following its commencement and seen in clinic for a six-month follow-up visit in January 2016. The patient has had an uncomplicated course thus far except for a small incisional hernia, and there is no evidence of hydatid disease recurrence on follow-up CT imaging.
Hydatid disease is most commonly caused by Echinococcus granulosus or Echinococcus multilocularis parasites, and 75% of infected cases present with liver involvement (Nunnari et al, 2012). Annually there are 1-200 cases per 100,000 individuals globally. The disease is most prevalent in sheep and cattle farming regions, especially in the Middle East, as seen with our patient (Nunnari et al, 2012). This case highlights the importance of pre-operative imaging in surgical cases, especially for hydatid cysts, the need for appropriate surgical consultation with experienced abdominal radiologists, and possibly repeating imaging closer to the date of surgery. Hydatid liver cysts can be diagnosed by distinguishing radiological features present on imaging, along with Echinococcal serology, and post-operative pathological investigation (Martel et al, 2014). This makes pre-operative imaging vital to the patient consultation before surgery, and to the surgical decision-making (Martel et al, 2014). The World Health Organization recommends surgical treatment of hydatid cysts if they are large, symptomatic, infected, and/or representing fistulization into neighbouring structures (WHO Informal Working Group, 1996). Radical surgical resection is the desired approach at Western tertiary HPB centres (Martel et al, 2014). Usually complete surgical removal would consist of a liver resection and peri-cystectomy; however, lack of experience in peri-cystectomy at Western centres is common, and therefore it is not frequently used (Kayaal, 2006; Martel et al, 2014). A recent study of the surgical treatment of hydatid liver disease at a North American tertiary HPB centre highlighted the rareness of operating on this condition, with only 40 cases occurring during a 14 year period (Martel et al, 2014). These cases were associated with a high rate of post-operative complications, as seen in 48% of patients. Most significantly, though, this retrospective review demonstrated that complete liver resection offers the best long-term outcomes in terms of minimal post-operative morbidity and high recurrence-free survival, as compared to the results achieved by the use of other surgical techniques (Martel et al, 2014). Therefore, the identification of hydatid liver disease pre-operatively by radiologic investigations is essential to ensure the best possible patient outcomes following surgery. This makes the surgeons aware of the most likely diagnosis beforehand and can help them properly prepare for the surgery in advance. In the case of this patient, finding hydatid liver cysts was completely unexpected intra-operatively, and serious complications could have arisen if the appropriate precautions had not been taken.
I would like to thank Dr. Guillaume Martel and Dr. Kristina Lemon for their invaluable support and assistance with this case report, and for their excellent guidance and teaching during my surgical elective.
Conflicts of Interest
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