Imaging features of abdominal non-organi lymphangioma / 中华消化外科杂志

ABSTRACT

Objective To summarize the computed tomography (CT),magnetic resonance imaging (MRI) and fluorine-18 fluorodeoxy glucose (18 F-FDG) positron emission tomography (PET)/CT features of abdominal non-organi lymphangioma.Methods The retrospective cross-sectional study was conducted.The clinical data of 16 patients with abdominal non-organi lymphangioma who were admitted to the Affiliated Hospital of Ningbo University (11 patients) and the Changhai Hospital Affiliated to the Second Military Medical University (5 patients) between January 2009 and December 2015 were collected.All the patients received CT,MRI and 18F-FDG PET/CT examinations.Observation indicators:(1) imaging examinations;(2) imaging features of CT and MRI;(3) imaging features of PET/CT;(4) treatment and follow-up.Operations were applied to patients based on agreements of patients and families after finishing preoperative examinations,and postoperative pathological examinations were also performed.Follow-up using outpatient examination and telephone interview was performed once every 6-12 months postoperatively up to July 2016.Results (1) Imaging examinations:of 16 patients,12 underwent plan and contrast-enhanced CT scans,5 underwent plan and contrast-enhanced MRI scans,2 underwent plan MRI scans and 1 underwent 18 F-FDG PET/CT scan.One patient underwent simultaneously CT,MRI and 18 F-FDG PET/CT examinations and 2 patients underwent simultaneously CT and MRI examinations.(2) Imaging features of CT and MRI:① Classification of lymphangioma:unilocular cyst,plurilocular cyst and lymphangiomatosis were detected in 6,9 and 1 patients,respectively.② Lymphangioma location:9 of lymphangioma located in the single regions (6 with unilocular cyst and 3 with plurilocular cyst),7of lymphangioma involved multiple regions (6 with unilocular cyst and 1 with lymphangiomatosis).③ Lymphangioma diameter:lesion diameter was 4-25 cm,with an average of 12 cm,and diameter in 9 of lymphangioma was more than 10 cm.④ Lymphangioma shape:3 lymphangiomas were regular-shaped,showing round-like changes,and 13 lymphangiomas were irregular-shaped,showing'moulding'-like changes.⑤ Internal structure of lymphangioma:internal structures in 12 patients undergoing plain CT scans presented as liquid low density,with homogeneous density and-10-19 HU of CT value.MRI scans in 7 patients showed low signal on T1WI and high signal on T2WI,with homogeneous signals.No bleeding was found inside the abdominal non-organi lymphangiomas of 16 patients.The fluid-fluid level was detected in 1 patient with lymphangioma due to bleeding in pathological changes of liver.The septa and wall thickness was less than 2 mm in 15 patients with lymphangiomas,and was more than 3 mm in 1 plurilocular cyst lymphangioma,showing a equal density and isointensities on T1WI and T2WI.There was no nodule and calcification in 16 patients.⑥ Lymphangioma boundary:15 patients had clear boundary of lymphangioma and 1 had an unclear boundary of lymphangioma.⑦ Extrusion of adjacent organs:lymphangiomas in 10 patients were local concave,showing arc-shaped impression and hilar depression,lymphangiomas in 4 patients showed surrounding blood vessels,and fat density or signal inside lymphangioma was found in 2 patients.There were no surrounding intestine and lymph node enlargement in 16 patients.⑧ Lymphangioma reinforcement:of 14 patients with contrast-enhanced scans,septa and wall of lymphangiomas demostrated slight enhancement in 13 patients and moderate enhancement in 1 patient,and all contents showed no enhancement.(3) Imaging features of 18F-FDG PET/CT:inhomogeneous uptake of FDG was manifested in 1 plurilocular cyst lymphangioma,metabolic activity of the lesion was slightly higher than liver,SUVmax=3.71.(4) Treatment and follow-up:14 patients underwent single resection of lymphangioma (6 with unilocular cyst and 8 with plurilocular cyst);1 patient with plurilocular cyst lymphangioma underwent resection of lymphangioma,descending part of duodenum,pancreatic head and ascending colon;1 patient with lymphangioma underwent splenectomy due to smaller lesion.Sixteen patients were confirmed with lymphangioma by postoperative pathological examinations.Of 16 patients,13 were followed up for 6-31 months,with a median time of 15 months.During the follow-up,12 patients had no recurrence,with satisfactory outcomes,and 1 with recurrence of lymphangioma underwent multiple cervical and thoracic resections under right arm and sclerotherapy.Conclusion Abdominal non-organi lymphangioma has some imaging characteristics,it usually manifests as a larger mass with plurilocular cyst,moulding,liquid density/signal,thin septa and wall and clearly boundary.Plurilocular cyst lymphangioma has uptake of 18F-FDG.