keywords
Introduction
Splenic cysts are rare in pediatric surgery. They can be classified as “true” cysts or pseudocysts on the basis of the presence or absence of an epithelial lining. Congenital cysts represent 10% of splenic cysts, most of which are epidermoid lesions[1]. Splenectomy was initially the surgical treatment employed due to size, risk of operative complications, and fear of postoperative bleeding[2]. With the introduction of minimally invasive surgery, several cases have been documented where laparoscopy has been used safely and with good results[2]. The use of laparoscopy is less aggressive, resulting in less postoperative discomfort, and requires a shorter stay in the hospital and with the same results as with the open approach[3-5]. We report a new case of congenital splenic cyst handled successfully by laparoscopy including a follow-up period of more than 2 years.
Case Report
An 11-year-old boy with left-sided palpable abdominal mass was admitted to our department for investigation of a splenic tumor in October 2005. He had no injury, or infection that might have caused splenic disease. Physical examination did not reveal any other pathologic finding except for an elastic, hard mass, (approximately 10 cm in diameter) that was palpable in the left upper quadrant. Ultrasonography (US) revealed a huge cystic lesion of the spleen measuring approximately 10 cm in diameter (Fig.1). Magnetic resonance imaging (MRI) showed a 10 cm large cystic lesion in the spleen (Fig.2A& B). The lesion was not enhanced after injecting contrast materials (Fig.2C). There were no laboratory findings of parasitic or bacterial infection. The results of routine laboratory examinations (including hemoglobin, complete blood count, renal and liver function tests, and coagulation profile) were normal.
Abdominal ultrasonography showing a large (about 10 cm in diameter) splenic hypoechoic lesion in the spleen.
A&B, Axial MRI showing a large cystic lesion about 10 cm in diameter occupied almost the entire spleen and displaced the stomach medially; which is hyperintense on T2-weighted image. C, Coronary MRI showing the lesion is not enhanced after injected contrast materials.
With the diagnosis of a giant splenic cyst, the patient underwent a laparoscopic operation under general anesthesia. During the operative procedure, the child was placed in a supine position. The first 10-mm trocar was placed in an opening way through the umbilicus. A pneumoperitoneum was established, with CO2 at a pressure of 10 mmHg. The cyst was situated on the outer side of the spleen and covered by omentum. Two 5-mm trocars were positioned under direct vision in the right upper abdomen and the left lower quadrant. There was no adhesion between the omentum and the anterior abdominal wall. A search revealed no accessory spleens. So, an unroofing procedure of the splenic cyst was done to preserve the function of the spleen. Approximately 700 ml of clear fluid was aspirated. The operation was finished after an adequate opening was created between the cyst and the celiac space. All incisions were closed in the usual way. The intraoperative and postoperative course was uneventful. The duration of surgery was 90 min, and the intraoperative blood loss was insignificant. The histopathology of the lesion showed characteristic features of a congenital splenic cyst (Fig.3).
Pathological examination showing the lining was composed of a single layer of flattened or low-cuboidal epithelium (H&E stain, × 100).
The patient was discharged on the sixth postoperative day in excellent condition, and was followed-up for more than 2 years with no evidence of recurrence.
Discussion
Non-parasitic cysts of the spleen are uncommon and of varying etiology. These lesions can be classified as true (primary), or false (secondary) cysts. True splenic cysts, which have a cellular layer, include vascular, serous and infectious cysts, congenital cysts, and neoplasms (epidermoid, dermoid, hemangioma and lymphangioma). Their prognosis is good. False cysts or pseudocysts, which have a fibrous capsule, may be post-traumatic, inflammatory or degenerative[6]. Approximately 25% of congenital splenic cysts are of unknown etiology. Possible etiological mechanisms include: i) involution and metaplasia of pluripotent cells in the splenic parenchyma during development; ii) inclusion of celomic mesothelium during organogenesis; iii) invagination of peritoneal endothelial cells (mesothelium) within the developing spleen; iv) dilatation of normal lymph spaces[7].
The majority of splenic cysts are benign. Some cysts, however, enlarge and become symptomatic with a risk of post-traumatic rupture, hemorrhage and infection[7]. The differential diagnosis of a fetal splenic cyst includes cystic masses in the upper left quadrant of the abdomen. They may arise from the urinary tract (renal cysts, cystic dysplasia, hydronephrosis, and obstructed duplication), genital tract (ovarian cysts and neoplasms, hydrosalpinx), adrenal gland, or gastrointestinal tract (duplication cyst, choledochal cyst, pancreatic pseudocyst, mesenteric cysts, omentum cysts and liver cysts).
The optimal treatment strategy for patients with nonparasitic splenic cysts remains controversial. Serial monitoring by ultrasound examination should be carried out in uncomplicated cases so that invasive therapy can be avoided. Cysts larger than 5 cm should be treated, as well as symptomatic and complicated cysts[7-9]. Percutaneous aspiration and sclerosis of cysts is reported to be ineffective[8,9]. Surgical treatment options for nonparasitic splenic cysts include spleen-preserving resection, either partial splenectomy, or cystectomy[10], or cyst decapsulation[11]. In the latter, a laparoscopic approach has been used increasingly in recent years. The procedure can involve complete splenectomy, partial splenectomy, marsupialization, or fenestration, the choice depending on the location of the cyst and the volume it occupies in the spleen. However, splenectomy in young patients entails a risk of overwhelming postsplenectomy infection and this may be avoided using spleen-preserving techniques. Therefore, the surgeon should attempt to preserve as much of the spleen parenchyma as possible. Thus, a laparoscopic unroofing technique was used. During the operation, the content of the cyst is aspirated at the beginning and followed by unroofing a part of the cyst wall. Although this technique is considered successful, there have been reports of recurrence, unless total removal of the cyst wall is performed[12]. Furthermore, we thought the adequate opening between the cyst and the celiac space is important to avoid recurrence.
In conclusion, laparoscopic treatment of a congenital splenic cyst that becomes symptomatic and potentially life-threatening through enlargement, rupture, or secondary infection is associated with minimal morbidity and a shorter hospital stay, as compared with open procedures.
Acknowledgements
The authors grateful acknowledge Dr. Linsheng Zhao and Chunxiang Wang, Tianjin Children’s Hospital, for their assistance with reproduction of photographic images.
- Received March 6, 2008.
- Accepted May 22, 2008.
- Copyright © 2008 by Tianjin Medical University Cancer Institute & Hospital and Springer