Update on MR Imaging of cystic retroperitoneal masses

Imaging Findings and Misdiagnosis of Bronchogenic Cysts: A Study of 83 Cases

Objective

We characterize computed tomography (CT) and magnetic resonance imaging (MRI) features of bronchogenic cysts (BCs) and analyze misdiagnosis.

Methods

The retrospective study consisted of 83 patients with BCs. CT and MRI images were assessed for mass location, maximum diameter, density, calcification, signal intensity, and enhancement pattern. Eighty-three patients underwent plain CT in which 53 underwent enhanced CT. Thirteen patients received both plain and enhanced MR, and only one received just a plain MR.

Results

Eighty-three masses were all solitary, with 71 having a roundish morphology, and twelve having a lobulated or irregular morphology. Sixty-six masses are mediastinal type, four are intrapulmonary type, and 13 are ectopic type. Calcification occurred in 14 lesions. On plain CT, 13 lesions displayed water-like attenuation (-20-20 Hu), and 70 showed soft-tissue attenuation (≥21 Hu). On T1WI, eight masses were hyperintense, three were isointense, and three were hypointense. Fourteen masses were hyperintense on T2WI and (Apparent Diffusion Coefficient) ADC sequence. On (Diffusion Weighted Imaging) DWI, six masses were hypointense and eight were hyperintense. Enhanced T1WI showed seven cases were unenhanced, while six were marginally enhanced. Twenty cases were misdiagnosed as thymomas, eleven as neurogenic tumors, six as lymphangiomas, and two as lung cancer. Five cases were misdiagnosed as other diseases. Patients with BCs underwent MR (42.9%) had a lower rate of misdiagnosis than those who underwent CT alone (53.0%).

Conclusion

The imaging findings of BCs in the chest are generally consistent. Misdiagnosis occurs frequently when CT attenuation values exceed 20 Hu. Diagnostic accuracy of BCs tends to improve with preoperative MR examination.

A Rare Case of Subclavicular Cystic Lymphangioma in Adults Adhering to Axillary Vessels

Cystic lymphangiomas are rare and benign lymphatic malformations. They often sit in the cervico-facial or axillary region. We report the case of a 31-year-old patient admitted for a left subclavicular mass symptomatic of pain on arm abduction. The CT scan of the chest suggests a cystic lymphangioma adhering to the axillary vascular pedicle. The patient had a complete resection of this mass with a simple postoperative course.

Adult upper-limb forearm lymphoma hygroma (cystic lymphangioma): A case report

INTRODUCTION

Lymphoma hygroma (LH) that is the most common type of lymphangioma, but it rarely occurs in the forearm. It may show localized invasive behavior, but is benign.

CASE PRESENTATION

A 42-year-old woman presented to our hospital with a growing strip-like mass in the right forearm that had been detected 3 years earlier. Ultrasound examination showed a subcutaneous strip of low back vocal cords on the right forearm. Further magnetic resonance imaging (MRI) showed irregular strip-like dilated lymphatic vessels characteristic of LH with low T1 signal intensity and high T2 signal intensity. After radical surgical resection, hematoxylin-eosin (H & E) and immunohistochemical (IHC) staining of cystic LH endothelial cells labeled with monoclonal antibody D2-40 showed a dilated lymphangioma with no evidence of malignancy. After 7 months of follow-up, no tumor recurrence was seen and the effect was satisfactory.

CLINICAL DISCUSSION

A combination of previous trauma history, signs and symptoms, and imaging evaluation are necessary to provide clues to LH, but the final diagnosis is likely to be made by pathologic evaluation of the resected specimen. Although there are many treatment modalities, all also have different outcomes. The absence of complete resection resulting in a tumor remnant is the foremost cause of LH recurrence, so we believe that the preferred approach against LH remains complete surgical resection.

CONCLUSIONS

LH is benign and generally asymptomatic lesions with mild bio-behavior. As there are occasional confusing presentations, similar cystic lesions should still be considered with caution for the disease. Although MRI provides superior advantages for its diagnosis, the confirmation of diagnosis still requires histological examination. Radical lesion resection is a very safe and effective option for the treatment of LH.

Retroperitoneal lymphangioma mimicking malignant tumor treated by pancreaticoduodenectomy

Lymphangiomas are classified as lymphatic malformations, which are more common in children and rare in adults. It frequently occurs in the cervical and axillary regions and uncommonly in the retroperitoneum. A 39-year-old woman presented to our department for the investigation for a 55 mm asymptomatic mass in the right anterior adrenal cavity. Abdominal ultrasound showed a tumor containing cysts in the right anterior adrenal cavity. Contrast-enhanced computed tomography showed that the tumor was poorly contrasted and ill-defined. Magnetic resonance imaging suggested that the tumor contained a small amount of fat. The tumor tended to grow, and the possibility of malignant diseases such as liposarcoma could not be excluded. Therefore, surgical resection was performed. Since intraoperative findings showed that the tumor tightly invaded to the duodenum and pancreatic head, a pancreaticoduodenectomy was selected. The entire tumor was removed without exposing the tumor. Macroscopic findings indicated that the specimen was 55 mm in size, indistinctly demarcated, yellow-white in color, and polycystic. Histologically, lymphovascular proliferation was observed with infiltration of the pancreatic head and the duodenal muscle layer. The diagnosis of lymphangioma was finally made. There was no recurrence 2 years after surgery.