MCLs are rare benign tumours of the lymphatic system with a reported incidence of less than 1 per 100 000 hospital admissions.1 2
Exact aetiology is unknown. It is probably a developmental anomaly of the lymphatic system,3
explained by its primary occurrence in children, with over 80% diagnosed in the first few years of life.4
However, they can also form secondarily as a result of inflammatory process, lymphatic obstruction, surgery, radiation and abdominal trauma.5 6
Over 95% of lymphangiomas are found in the head, neck and axillary region. Isolated small bowel lesions are seen in less than 1% of cases,7
but this accounts for 70% of all intraperitoneal lymphatic tumours.
MCLs are classified as simple, cavernous and cystic.8
The simple type is mostly situated superficially in the skin and is composed of small thin-walled lymphatic vessels, while the cavernous variety has dilated lymphatic vessels and has connection with the normal adjacent lymphatics.8
Cystic lymphangioma, which was reported in our patient, is composed of large macroscopic lymphatic spaces surrounded by collagen and smooth muscles and does not have connection with adjacent normal lymphatics (CD34 and CD31 positive).8
Lymphangiomas are rarely seen in adults4
and are either discovered incidentally or may present with features of acute abdomen, as in our case, requiring urgent surgical intervention. There is literature evidence of this rare tumour presenting with life-threatening complications, which include traumatic rupture, anaemia secondary to intra-abdominal or intra-cavitary bleeding, intestinal gangrene secondary to volvolus and intermittent intestinal obstruction.1 5 8
Only three cases have been reported having some resemblance as noted in our case.
The role of plain abdominal film is debatable as no diagnostic features are confirmatory of lymphangiomas but would show evidence of intestinal obstruction.1 3
Ultrasonography, which has a high diagnostic yield for cystic lesions, is sensitive and relatively specific for diagnosing MCL.9
CT and MRI both give precise information of the size, anatomical location, extent of cysts and involved structures for the operative intervention;6 10
however, they are insufficient in establishing an accurate preoperative diagnosis9
as was evident in our case.
Primary treatment of MCL is radical surgical excision even when asymptomatic for its potential to grow enormously to invade adjacent structures, develop complications and its risk of sarcoma transformation on irradiation.6 10
However, radical excision can sometimes be technically impossible due to its infiltration of vital structures.11
MCL has been classified into four categories by way of the relation between the cyst and the intra-abdominal anatomy (degree of mesenteric or abdominal organ involvement) to optimise surgical planning.1 6
Type 1: pedicled; type 2: sessile and less mobile and may alter the bowel's vascular supply requiring bowel resection, as in our case;3
type 3: retroperitoneal extension and can involve vital structures; and5
type 4: multicentric having doubtful prognosis especially in cases with extensive organ involvement.
Small bowel volvulus is rare in adults12
with two distinct categories: primary type defined as torsion of the small bowel mesentery without evidence of predisposing anatomical abnormalities and secondary type precipitated by underlying anatomical abnormalities, including postoperative adhesion, malrotation, congenital bands, intussusceptions, colostomy, fistula, tumours and Meckel's diverticulum.12
Large mesenteric masses can rarely cause volvulus of the small bowel.6 13 14
Our patient's initial presentation was features of subacute bowel obstruction. Despite extensive investigations, recurrent volvolus of the small bowel due to the MCL was elusive. He was enlisted for an elective exploration; however, recurrence of his symptoms required early intervention that confirmed the MLC causing volvulus of the mid small bowel as a closed loop obstruction accounting for his symptoms. Our patient had a risk of life-threatening complication of ischaemia and infarction of the small bowel. Timely surgical intervention and radical excision helped to preserve most of the small bowel with a successful outcome.
Our conclusion is that mesenteric lymphangioma should be included in the differential diagnosis of acute mechanical small bowel obstruction in a young adult in the absence of previous history of operative intervention and hernia.
- Mesenteric lymphangioma should be included in the differential diagnosis of acute mechanical small bowel obstruction.
- Primary treatment of MCL is radical surgical excision even when asymptomatic because of its potential to invade adjacent structures.
- Preoperative investigations, including CT and MRI, give information about the size, anatomical location and extent of cysts; however, they are insufficient in establishing an accurate preoperative diagnosis.
- Early surgical exploration can prevent life-threatening complications that include traumatic rupture, intra-abdominal or intra-cavitary bleeding and intestinal gangrene secondary to volvolus.