Mesenteric Cysts Surgical Triumph in Rare Abdominal Case

Mesenteric cysts, although rare, represent intriguing abdominal lesions that have the potential for malignant transformation in a small percentage of cases. These cysts often present with vague and variable symptoms, and in approximately 40% of cases, they are discovered incidentally during physical examinations or imaging procedures.

While mesenteric cysts can affect individuals of any age, they typically manifest in the first decade of life, with an equal gender distribution. These cysts can develop in various parts of the mesentery, with the most common locations being the mesentery of the small bowel (ileum: 60%) and the mesocolon (ascending colon: 24%). A recent case at King Faisal Hospital highlighted the diagnostic challenges and management of mesenteric cysts.

A 20-year-old unmarried female sought medical attention due to a painless abdominal swelling in the right upper quadrant that had persisted for three months. The swelling had gradually increased in size and was accompanied by symptoms of nausea and anorexia. Importantly, the patient did not report abdominal pain, vomiting, changes in bowel habits, hematemesis, melena, or urinary symptoms.

Moreover, there was no history of fever or abdominal trauma. The patient had experienced weight loss over several months, leading to noticeable pallor but without episodes of dizziness or palpitations. She had regular menstrual cycles, and there was no family history of similar mesenteric diseases, malignancies, or congenital anomalies. Her past medical history was unremarkable, with no prior surgical interventions or medication use. This case report was published in Cureus.  

Upon clinical examination, the patient appeared conscious, oriented, and not pale, with vital signs within normal limits. Abdominal examination did not reveal signs of distension or swelling. However, a round mobile cystic mass was palpated in the right hypochondrial region, becoming more prominent when the patient lay on her left side.

Importantly, the mass was not tender and measured approximately 7 x 10 cm in size. Bowel sounds were positive, and there were no observable skin changes or dilated veins. A digital rectal examination did not reveal any external pathologies or palpable masses, and no lymph nodes were palpable. The etiology of mesenteric cysts remains unclear, but several potential contributing factors have been proposed.

These include a failure of lymph nodes to communicate with the lymphatic or venous systems, as well as blockages within the lymphatic system resulting from previous pelvic surgery, trauma, pelvic inflammatory disease, infection, endometriosis, or neoplasia. To further investigate the patient’s condition, she underwent an exploratory laparotomy.

This surgical procedure revealed a cyst measuring 9 x 9 cm arising from the transverse mesocolon, exerting pressure on parts of the duodenum. The cyst contained brownish fluid. The surgical team carefully dissected adhesions between the cyst and the surrounding structures. The nature of the cyst’s adhesion to the colon and its mesentery necessitated partial resection of approximately 8 cm of the transverse colon, followed by a side-to-side anastomosis. 

While mesenteric cysts are typically benign, they often present with variable and nonspecific symptoms, such as abdominal pain, nausea, vomiting, anorexia, and changes in bowel habits. Additionally, they can lead to complications such as intestinal obstruction, volvulus, torsion, bleeding, or rupture. These cysts are more commonly found in the small intestine (66%) compared to the large intestine (33%). In cases involving the large bowel, they tend to occur in the right colon, though they can rarely affect the mesentery of the descending colon, sigmoid colon, or rectum. 

Diagnosing mesenteric cysts can be challenging due to their ability to mimic other pathologies, including pancreatic pseudocysts, cystic tumors, pelvic diseases, and aortic aneurysms. The use of imaging techniques, such as ultrasonography (US), CT scans, and nuclear MRI, can assist in achieving a preoperative diagnosis. CT scans, in particular, play a crucial role in localizing the cystic mass and identifying the involved anatomical structures, aiding in surgical planning. 

Despite extensive research, the exact cause of mesenteric cysts remains uncertain. Proposed theories include disturbances in lymphatic drainage, venous drainage, or the blockage of lymphatic vessels due to various factors like prior surgeries, trauma, infections, or inflammatory conditions. Complete surgical excision is considered the primary treatment for mesenteric cysts, primarily to prevent recurrence and reduce the risk of malignant transformation.

Surgical removal may entail resection of part of the mesentery along with the cyst. The choice between laparotomy and laparoscopy depends on factors such as cyst size, its relationship with surrounding abdominal structures, and the surgeon’s expertise.

In the case discussed, a laparotomy was chosen as the preferred procedure, and the patient underwent successful surgical resection of the cyst, which, due to its adherence to the colon and its mesentery, required partial colon resection. Mesenteric cysts, though rare, present unique challenges in terms of diagnosis and management.

This case exemplifies the importance of considering mesenteric cysts as a differential diagnosis when evaluating abdominal masses and highlights the potential complications associated with these cysts. With advancements in imaging techniques and surgical approaches, medical professionals can provide effective care and treatment for patients with mesenteric cysts, emphasizing the importance of complete surgical excision to ensure the best possible outcomes and minimize the risk of recurrence and malignant transformation.