Laparoscopic excision of a large retroperitoneal lymphovascular malformation in an adult.

Retroperitoneal lymphangioma is a rare benign tumour of the retroperitoneal lymphatics that usually manifests in infancy. It is worth reporting of an unexpected presentation, especially in an adult. They frequently affect the neck (75%) and the axilla (20%). Intra-abdominal lymphangiomas (<5%) have been reported in the mesentery, gastrointestinal tract, spleen, liver and pancreas. Retroperitoneal lymphangiomas account for nearly 1% of all lymphangiomas and are uncommon incidental findings usually at surgery, autopsy or lymphography. Differentiating cystic lymphangiomas from other cystic growths by imaging studies alone is often inconclusive, and surgery is frequently required for definitive diagnosis. An interesting and rare case of a retroperitoneal lymphangioma in an adult patient which was removed laparoscopically is described here.

INTRODUCTION

Lymphangiomas are slow-growing benign lesions characterised by proliferating lymphatics.[1] These may be capillary, cystic or cavernous. Although retroperitoneal lymphangiomas may sometimes be asymptomatic,[2] they usually present as a palpable abdominal mass and are easily confused with other retroperitoneal cystic tumours including those arising from the liver, pancreas and kidney. They may become symptomatic if they become large enough to impose on surrounding structures. They manifest with clinical symptoms of abdominal pain, fever, fatigue, weight loss and haematuria due to their size, and occasionally might be complicated by intra-cystic haemorrhage, rupture, volvulus or infection.[34]

CASE REPORT

A 22-year-old male presented with nausea and abdominal pain which was diffuse, cramping type with no aggravating or relieving factors for a few weeks. There was no history of per rectal bleeding, dysuria, dyspnoea or vomiting. The abdominal distention was moderate and no mass was palpated per abdomen. The bowel sounds were normal. His past medical and surgical history was not significant.

Laboratory parameters were within normal limits. Contrast-enhanced computed tomography of the abdomen showed a large 94 mm × 41 mm × 38 mm lesion with thin mildly enhancing septations, anterior to the left kidney and psoas muscle, lateral to aorta and posterior to the pancreas, encasing the left renal vein and ureter. There was no associated ascites or bowel obstruction. With a pre-operative diagnosis of retroperitoneal lymphangioma, the patient underwent laparoscopic total excision of the cyst.

Under all aseptic precautions and general anaesthesia with the patient in the supine position and the left side tilted slightly upwards, pneumoperitoneum was created and a subumbilical 10 mm port was introduced for the scope. Under direct vision, two additional 5 mm ports were inserted, one in the midline 5 cm above the umbilicus and the other in the left lower quadrant parallel to the umbilicus. Figure 1 shows an intra-operative image of the lymphovascular malformation.

Figure 1

Intra-operative image showing vital steps of surgery

Laparoscopy revealed a large retroperitoneal lymphovascular malformation after mobilisation of the left colon. The mass was separated posteriorly from the left kidney, psoas muscle and the pancreas and medially from the aorta. Posterolaterally, the mass was encasing the left renal vessels and ureter. Apart from the usual monopolar electrocautery, ultrasonic scalpel was also used which made the dissection and mobilisation much easier. The mass was excised completely with meticulous dissection and thus preserving the renal vessels and ureter. For retrieval of the specimen, the cyst was punctured, contents were aspirated and the cyst wall was extracted through the 10 mm port. Figure 2 shows the retrieved specimen.

Figure 2

Specimen image after complete excision and retrieval

The patient was shifted to ward and post-operative course was uneventful. The patient was asymptomatic at 2 weeks, 1 month and 6 months of follow-up after discharge. Repeat ultrasound scan of the abdomen and pelvis was done during each follow-up and there was no evidence of any residual cyst or retroperitoneal collection.

Gross examination of the specimen showed a mass of yellowish brown tissue measuring 5 cm × 2 cm × 1 cm while microscopy revealed numerous small to large vascular channels lined by endothelial cells, lymphoid aggregates and presence of adipose tissue and fibro-collagenous tissue infiltrated by mixed inflammatory cells, which was suggestive of cystic lymphangioma. Figure 3 shows a microscopic image of the mass.

Figure 3

Histopathology picture showing numerous small to large vascular channels lined by endothelial cells with lymphoid aggregates and presence of adipose and fibro-collagenous tissue infiltrated by mixed inflammatory cells

Thus, the diagnosis of a retroperitoneal lymphangioma was histologically confirmed.

DISCUSSION

A retroperitoneal tumour accounts for a wide differential diagnosis, including malignant tumours such as mesothelioma, undifferentiated sarcoma, mesenchymoma, benign tumours such as lymphangioma and other tumours such as retroperitoneal haematoma, haemangioma, duplication cysts, ovarian cysts and pancreatic pseudocysts.[5]

Lymphangiomas are benign lesions characterised by proliferating lymphatic vessels. Approximately, 50% of lymphangiomas are present at birth and almost 90% are diagnosed before 2 years of age. They occur in any location where lymphatics are encountered. The most frequently affected sites are the head and neck (75%), where they are commonly referred to as cystic hygromas, followed by the axilla (20%).[6] The remainder (approximately 5%) of the lymphangiomas are intra-abdominal[7] arising from the mesentery or greater omentum[8] where they are referred to as ‘mesenteric or omental cysts’. The retroperitoneum is the second most common location for the lymphangiomas.

In general, lymphangiomas are classified into three types; capillary, cavernous and cystic, depending on the size of the lymphatic spaces.[5] Retroperitoneal lymphangiomas are almost always benign.[3] It is speculated that their development is due to an abnormal connection between the iliac and retroperitoneal lymphatic sacs and the venous system, leading to lymphatic fluid stasis in the sacs.

Majority of the retroperitoneal lymphangiomas are asymptomatic[2] and are discovered incidentally. The most common clinical manifestation is that of a slowly enlarging abdominal mass[34] with abdominal pain, nausea and loss of appetite, as seen in this case.

A simple total excision is usually the preferred treatment and the outcome is generally good. Other forms of surgical management such as cysto-enterostomy or marsupialisation have now become obsolete.[3] There is a possibility of recurrence with incomplete removal[13] of the lesion, arising from or involving an abdominal organ.[3]

We performed a simple laparoscopic excision of the retroperitoneal lymphangioma that was an appropriate treatment for our patient.

Cystic lymphangioma, a malformation of the lymphatic vessels, should be considered among the many differential diagnosis of a retroperitoneal cystic lesion. These rare tumours have an excellent prognosis after complete surgical excision with symptomatic relief and cure.

CONCLUSION

Retroperitoneal lymphangioma is a rare benign tumour with unclear intra-abdominal manifestations and its laparoscopic excision is feasible, safe and provides excellent cosmesis and has all the other advantages of laparoscopy.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.