Imaging Features of Cervical Lymphangiomas As A Cause of Respiratory Distress and Vascular-Lymphatic Disturbance

Abstract

Objective

Our aim is to present the imaging features of cervical lymphangiomas, which may be related with respiratory and vascular disturbances.

Materials and Methods.

Nine patients with cervical lymphangioma were evaluated with ultrasound (US), computed tomography (CT), and/or magnetic resonance imaging (MRI). While one case was a fetus in the second trimester, eight cases with tracheal stenosis were neonates or in childhood.

Results

One case was diagnosed in utero with US. All lymphangiomas were hypoechoic on the US and were of low-density (20–25 HU) on the CT. They showed a heterogeneous hypo- or hyperintense signal on T1-weighted MR images and a heterogeneous hyperintense signal on T2-weighted images. Upon contrast-enhanced CT and MR imaging, mild contrast enhancements were detected, particularly on the thick septations.

Conslusion.

Cervical lymphangiomas present as cystic lesions with septations, and they may cause respiratory distress or vascular-lymphatic disturbance.

Introduction

Lymphangiomas are benign congenital lesions of unknown origin, believed to originate from congenital obstructions of lymphatic drainage. Although they are most commonly found as asymptomatic cervical masses, their clinical course varies from aggressive infiltration into surrounding structures to complete spontaneous regression [1]. When they grow aggressively, substantial disfigurement and management problems occur as a consequence [2]. Mediastinal extension of the lesion may cause life-threatening complications such as a vascular-lymphatic disturbance or a respiratory tract obstruction on the trachea and main bronchus.

Materials and Methods

Nine patients with cervical lymphangiomas were evaluated with ultrasound (US), computed tomography (CT), and/or magnetic resonance imaging (MRI). One case was diagnosed in utero at 17 weeks of gestation with routine US scanning. While five of the cases were neonatal with cervical lesions, three cervical lymphangiomas were detected in childhood. All lymphangiomas were presented clinically as cervical masses, and three of the neonatal cases were admitted with respiratory distress. All of the cases were evaluated with US. CT scanning and MRI were performed with contrast enhancement. In all cases, a pathologic examination confirmed the diagnosis of a lymphangioma.

Results

The prenatal cervical lymphangioma was diagnosed with a routine US examination, and it was detected as a cervical cystic mass with thin septations (Fig. 1). Although there were no other fetal anomalies, a follow-up US examination showed massive pleural fluid collection and an enlargement of the cyst. Because there was no cardiac activity, a fetal abortion was induced at this time. Upon macroscopic examination, the fetus had a cervical cystic lesion, extending into the upper mediastinum (Fig. 2). In a childhood case, the cervical cysts extended to the level of the main bronchus (Fig. 3). Although the cysts showed thin septations as linear structures in four cases, they had thick septations in two cases and thick septations with solid parts in three cases (Fig. 4a–b). The lesions were of low density (20–25 HU) on the CT. Six cases showed a heterogeneous hypointense signal on the T1-weighted images and a hyperintense signal on the T2-weighted images (Fig. 5). The cysts of two cases had heterogeneous high signal on the T1- and T2-weighted images. On the contrast-enhanced CT and MR images, mild contrast enhancements were detected on the septations (Fig. 6).

Fig. 1.

Prenatal US scan showing an anechoic fetal neck lesion with thin septations.

Fig. 2.

Aborted fetus with a neck mass extending into the upper mediastinum.

Fig. 3.

Upon intravenous contrast enhanced computed tomography, the hypodense mass with cystic density extends from the cervical region to the level of the heart and carina. There are also mild contrast enhancements of the septations.

Fig 4A, B.

US scans show a mixed solid and cystic neck mass with internal thin septations and posterior acoustic enhancement (A) and a cystic lesion with thick septations and a solid part (B).

Fig 5A, B.

A newborn with an anterior neck mass (A). Upon T1-weighted MR imaging (TE/TR, 450/20), the mass has a heterogeneous low signal intensity with hyperintense septations.

Fig. 6.

A computed tomography scan showing the hypodense cervical mass with contrast-enhancing septations and a narrowed trachea.

Discussion

Lymphangiomas are congenital cystic lesions. Cysts having thin walls may vary from capillary size to a few centimeters, and they may be unilocular or multilocular [3]. While the cystic content is usually wealthy for protein, it may be hemorrhagic or infected in cases of combined venous-lymphatic malformation. In nearly all cases, there are internal focal inhomogeneities corresponding to fibrous septa visualized as linear structures of variable thickness. Although the cysts occurring in loose tissues have well-defined and regular borders, the other lesions arising in more strict tissue have poorly defined borders. Histologically, lymphangiomas are divided into three types as simple lymphangiomas, cavernous lymphangiomas, or cystic hygromas according to the size of the lymphatic channels [2].

About 70–80% of lymphangiomas localize in the neck, and the others typically appear in the axilla, mediastinum, mesentery, retroperitoneum, orbita, and bones [1,2]. Cervical lymphangiomas usually occur in the posterior triangle of the neck, and 3–10% of these lesions may extend into the upper mediastinum [2]. Although these lesions are frequently asymptomatic, they may rarely be symptomatic due to complications. During the intrauterine period, they may cause fetal deterioration by the mass effect on the neck and mediastinal structures such as the esophagus and main vessels, as in the presented fetal case. In neonates, they may be associated with a high risk for potentially life-threatening complications such as severe osteolysis of adjacent bone, infection of the lesion with bacteremia, and respiratory distress secondary to tracheal compression. Therefore, a prompt and accurate diagnosis and immediate treatment of the lesion may be required. Although spontaneous regression of the lesions may occur, they usually gradually enlarge with a patient’s growth. Acute overgrowth of the masses occasionally occurs as a consequence of infection or hemorrhage [3,4].

Because the mass recurrence will occur with an inadequate tumor resection, preoperative evaluation of the full extent and relationship of the tumor with adjacent vessels is crucially important. Lymphangiomas may be diagnosed by US during the intrauterine period. Magnetic resonance (MR) imaging may be useful for a differential diagnosis and evaluation of the mass extent at this time [5]. Although mediastinal extension of cervical masses could be shown with US on neonates, a CT scan is superior to US on the determination of the extent within the thoracic cavity and deep structures of the neck [2]. On a CT scan, they are visualized as cystic masses with a characteristic feature such as an ‘enveloping effect’ around the trachea, esophagus, great vessels, and even the heart [6]. While cysts frequently have low attenuation values, these values may be variable depending on the nature of the cystic content. MR imaging is more sensitive than CT scanning and US for the delineation of a lesion’s nature and extent. The relationship with adjacent vessels and muscles may also be clearly visualized. Upon MR imaging, lymphangiomas have typically heterogeneous low signal intensity similar to those of muscles on T1-weighted images and a higher signal intensity than fat on T2-weighted images. However, they may show variable signal intensities due to variable protein content or hemorrhage on T1- and T2-weighted images [2]. Our cases showed similar signal intensities on the non-contrast series and mild contrast enhancements of internal septations on the contrast enhanced series.

Branchial cleft cysts and thyroglossal duct cysts may be considered in differential diagnose, in spite of their usual unilocular nature and rare localization in the posterior triangle of the neck. While hemangiomas have similar MR imaging features with lymphangiomas, it may be suggested in cases where the feeding arteries and/or draining veins can be visualized. Although the abscesses may also have a cystic nature similar to a lymphangioma, they have a thick wall and a prominent capsular feature that are revealed by contrast enhancement, differentiating them from lymphongiomas [2]. In contrast to cranio-cervical masses such as cystic teratoma, meningo-encephalocele, or other neural tube defects, lymphangiomas do not have solid components with intact medullary channels.

The main therapeutic route is a total surgical resection of the cysts with a preoperatively accurate delineation of the extent, size, and location of the lesion [2]. The surgical treatment for mediastinal cysts may be performed by thoracotomy or thoracoscopic surgery [7]. Radiotheraphy is currently controversial, because it has some complications such as necrosis, radiation injury, growth retardation, malignant transformation for angiosarcoma, and other radiation-related malignancies [4].

In summary, a cervical cystic lesion in the intrauterine period or childhood is suggestive of cervical lymphangioma, and attention should be paid to respiratory distress or vascular-lymphatic disturbance.