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Laparoscopy for evaluating mesenteric lymphangiomatosis: A case report

Background Lymphangiomatosis is an extremely rare disease with potential soft tissue, bone, and spleen involvement, which can be characterized by lymphangioma. Only a few cases of colon and mesenteric lymphangiomatosis have been reported. We report a case presenting with fatigue, periumbilical pain, and intermittent bloody stools. This patient underwent a series of examinations. Exploratory laparoscopy, in particular, yielded very valuable images and videos for this disease, which can provide evidence for the diagnosis of this disease. Case summary The current patient had fatigue, periumbilical pain, and intermittent bloody stools. Colonoscopy indicated numerous variable-sized hyaline cysts in the colon. Submucosal puncture was performed during colonoscopy. The patient was readmitted to the hospital due to periumbilical pain. B-ultrasound and abdominal CT showed multiple hypoechoic nodules in the mesenteric area. Exploratory laparoscopy was performed, and histopathology revealed that D2-40 was positive. Based on auxiliary examination and laparoscopic biopsy, surgeons and pathologists reached the diagnosis of mesenteric lymphangiomatosis. Conclusion Clinicians need to comprehensively improve their knowledge of lymphangiomatosis, and the combination of clinical symptoms, histological characteristics, and colonoscopy biopsy findings should be considered to improve lymphangiomatosis diagnosis, thereby reducing misdiagnosis. Core tip Colon and mesenteric lymphangiomatosis is an extremely uncommon benign condition of unknown etiology and pathogenesis in adult patients. We report a case of mesenteric lymphangiomatosis in a 37-year-old woman who presented with fatigue, periumbilical pain, and intermittent bloody stools, as well as lesions in the kidney, spleen, and bones. This case provides new insights into the diagnosis and treatment of this disease.


Introduction
Colon and mesenteric lymphangiomatosis is an extremely uncommon benign condition of unknown etiology and pathogenesis, which could lead to compression symptoms caused by mechanical pressure. Here, we report a case of abdominal lymphangiomatosis evaluated by laparoscopy, which has not been previously reported.

Case presentation
Colonoscopy indicated numerous variable-sized hyaline cysts, involving the ascending colon, transverse colon, and descending colon ( Figure 1A), while no biopsy was carried out. Submucosal puncture was performed during colonoscopy. One year later, the patient returned with periumbilical pain. In abdominal ultrasound, multiple hypoechoic nodules with marked intranodular blood flow were observed in the spleen with a maximum size of 1.2 * 1.2 cm, with well-defined margins. In the inferior pole of the left kidney, a hypoechoic nodule was found, with an approximate diameter of 1.6 cm and no blood flow signal. Enlarged lymph nodes (1.9 * 1.1 cm 2 ) were found in the retroperitoneum (Figures 2A-C). Abdominal CT revealed multiple diffuse low-density shadowing zones without enhancement distributed in the mesenteric area, which partly surrounded the small bowel and presented a doughnut shape. The boundaries were blurred ( Figure 2D). Lowdensity shadowing zones were observed in the left kidney, spleen, ilium, and fifth lumbar vertebra on CT scan images ( Figures 2E-H). Based on the images, lymphangiomatosis was highly suspected, which was further confirmed by laparoscopic biopsy ( Figure 3A). Further exploratory laparoscopy showed numerous hyalines, smooth-walled, variable-sized cystic microstructures in the root of the mesentery, involving total mesenteric excision ( Figure 3B). The liquid inclusions were clear and pale yellowish (Video S1). Histopathology revealed diffuse or multi-centric proliferation of thin-walled, dilated lymphatic vessels ( Figure 4A). D2-40 (a monoclonal antibody), a highly sensitive and specific marker of lymphatic endothelium in the normal tissue and a subset of vascular lesions, confirmed mesenteric lymphangiomatosis by immunoreaction ( Figure 4B). D2-40-positive lymphatic vessels were shown in mesentery ( Figures 4C, D). The patient was treated with sirolimus (0.8 mg/ m 2 , Bid) for 3 months, and follow-up colonoscopy was performed. Colonoscopy indicated decreased number and size of cysts compared with the condition observed 6 months before ( Figure 1B).

Discussion
In 2014, generalized lymphatic anomaly (GLA) was proposed by the International Society for the Study of Vascular Anomalies (ISSVA) as a new term for lymphangiomatosis (1).
Mesenteric lymphangiomatosis is a benign cystic tumor of lymphatic vessels that occurs rarely in adults, while its etiology and pathogenesis remain elusive (2). It has variable clinical presentations and can involve different sites, including the mesentery, bone, spleen, mediastinum, lungs, and soft tissues (3). The clinical course and compression symptoms are directly correlated to the affected sites, mechanical pressure, and extent of the disease. In most cases, these lesions are multicystic and characterized by hypodense regions on CT images, without increased vascular flow on color Doppler ultrasound. We analyzed 11 previous cases of lymphangiomatosis involving the gastrointestinal tract and summarized them in Table 1. We listed the symptom and examination procedure of these cases so that colleagues can learn more about the disease. Reviews of the literature confirm that lymphangiomatosis progresses slowly and can be well controlled with appropriate treatment. A case report of mesenteric lymphangiomatosis indicated that surgical resection of the mesentery could be an option in case of mechanical obstruction (15). However, the defect caused by the operation may lead to internal herniation, eventually resulting in bowel obstruction and intestinal volvulus. Repairing the defect with Permacol was performed with no complications after 4 years (14). Biomaterial implant may be an option for closing the mesenteric defect caused by surgery. Lymphorrhea after open or laparoscopic biopsy is  one of the possible complications. Minor lymphatic leakage can be resolved by conservative management. Massive lymphatic leaks can be treated by embolization, but surgery may be necessary in some cases (16). Regarding the pharmacotherapy of lymphangiomatosis, sirolimus is an inhibitor of mammalian target of rapamycin (mTOR). Elisa Boscolo reached the conclusion that sirolimus suppresses the growth of lymphatic endothelial cells by inhibiting VEGF-Aand VEGF-C-driven proliferation and migration, thus impeding lymphangiogenesis (17). It is very effective in the treatment of multiple complicated vascular anomalies and has potential antitumor effects (18). Follow-up of the present case observed a significant decrease in number and size of cysts by colonoscopy.
Exploratory laparoscopy has not been utilized to evaluate mesenteric lymphangiomatosis so far, although a case report suggested that surgical resection of the mesentery could be an option in case of mechanical obstruction (14). The present case revealed the multi-systemic imaging manifestations of a rare systemic disease and highlighted the importance of exploratory laparoscopy in the diagnosis of mesenteric lymphangiomatosis.

Data availability statement
The datasets presented in this study can be found in online repositories. The names of the repository/repositories and accession number(s) can be found in the article/Supplementary Material.