Congenital cystic masses of the neck: radiologic-pathologic correlation

Tumeurs et malformations vasculaires, classification anatomopathologique et imagerie

The understanding of vascular anomalies (vascular tumours and vascular malformations) was obscured, for a long time, by confusion and uncertainties in nosology and terminology. The International Society for the Study of Vascular Anomalies (ISSVA) recently adopted a classification scheme, clearly separating vascular tumours (hemangiomas of different types) which result from active cell proliferation, from vascular malformations, which are inborn defects in vascular morphogenesis. These two types of lesions have different clinical behaviour and require different diagnostic and therapeutic strategies. The most frequent vascular tumour is infantile hemangioma. Its clinical aspects and evolution are well-known. New data have been recently obtained concerning the phenotype of tumour cells and its histogenesis. Of the numerous new vascular tumours, which have been recently described, only the congenital hemangiomas, the vascular tumours associated with the Maffucci syndrome and the tumours that may be complicated by a profound thrombocytopenia (Kasabach and Merritt phenomenon) will be considered. Vascular malformations can be classified according to the vessel(s) types they are composed of. A classification table is presented, separating the malformations of vascular trunks from tissular malformations which are more intimately embedded in the surrounding tissues. The different syndromes associated with vascular anomalies take also place in this table. The clinical, imaging and histological aspects of the most frequent malformations (capillary, venous, lymphatic and arteriovenous) are presented. This classification intend to clarify the nosology and terminology of the complex field of vascular tumours and malformation and to offer a common language to the different physicians and specialists contributing, preferably with a interdisciplinary approach, to the diagnosis and treatment of these difficult lesions.

A rare cause of parotid swelling: Primary hydatid cyst

Hydatid disease is a zoonotic infection caused by Echinococcus species. Cystic form of this infection mostly involves liver and lung. Hydatid disease of the parotid gland is a very rare entity that may be easily overlooked in daily practice. On the other hand, rupture of the cyst during surgery may give rise to serious complications. We present a case of hydatid cyst of the parotid and discuss the differential diagnosis of this rare condition.

Multimodality imaging evaluation of the pediatric neck: techniques and spectrum of findings

Neck masses are a common finding in children and can present a difficult diagnostic challenge. These masses may represent a variety of conditions having a congenital, acquired inflammatory, neoplastic, or vascular origin. The fascial spaces and compartments of the neck provide an approach to differential diagnosis, and extensive knowledge of the anatomy and contents of each cervical compartment is mandatory in the diagnosis of pediatric neck lesions. Several imaging techniques, including radiography, gray-scale and Doppler ultrasonography, conventional and three-dimensional computed tomography, magnetic resonance (MR) imaging, and MR angiography, have been proposed for the evaluation of such lesions, and each has its own advantages and limitations. The imaging findings in 120 children who had been referred or treated for cervical lesions were retrospectively reviewed, and a systematic multimodality imaging approach to pediatric neck lesions based on the involvement of anatomic compartments of the cervical region was developed to increase diagnostic efficiency. Careful attention to clinical history and physical examination findings, along with knowledge of the embryologic features and anatomy of the cervical region and a multimodality imaging approach, is very helpful in the diagnosis and management of pediatric neck lesions.

A case of mesenteric cystic lymphangioma: fat saturation and chemical shift MR imaging

Mesenteric cystic lymphangioma is an uncommon lesion that may be difficult to diagnose radiologically. In our case, a septate cystic mass showed fluid attenuation on a computed tomography scan. We were able to define the fat content within the cystic tumor by magnetic resonance (MR) imaging. The presence of fat within an intra-abdominal cystic mass is suggestive of a dermoid cyst, cystic lymphangioma, or lymphocele. The pathologic diagnosis revealed a cystic lymphangioma, which originated from the mesentery. Although the MR imaging features of dermoid cysts and lymphangiomas are well known, the demonstration of fat content by chemical shift and fat saturation MRI has not yet been reported for a cystic lymphangioma.

Vascular malformations in the extremities: emphasis on MR imaging features that guide treatment options

Vascular malformations can be classified into high-flow arteriovenous malformations (AVM) and low-flow venous or lymphatic malformations (VM/LM). VMs and LMs have the ability to cross multiple tissue boundaries. Not only is subcutaneous tissue often involved, but multiple muscle groups, tendons, bone cortex and bone marrow are also not uncommonly violated. Magnetic resonance imaging (MRI) provides valuable information for the assessment and treatment of malformations. Firstly, MRI can characterize the flow pattern of these malformations to guide treatment towards trans-arterial embolization for AVMs and percutaneous embolization for low flow malformations. MRI is essential to define the anatomic extent and involvement of various tissue layers (a distinct advantage over ultrasound), and to correlate treatable components of the malformation with patient symptoms. Treatment is decided by the need to alleviate clinical symptoms, and is dependent on the extent of the malformation as defined by MRI. We present MRI features of vascular malformations to demonstrate the potential spectrum of involvement of these lesions, illustrating the value of MRI in treatment planning.

Thyroglossal Duct Cysts: A Consideration in Adults

Thyroglossal duct cysts (TDC) are one of the most common pediatric midline neck lesions. Although they are present from birth, they usually become symptomatic in early childhood as a mass or draining sinus. Infection and abscess formation are frequent complications due to a communication between the cyst and the mouth with subsequent contamination by oral flora. We present a case of a 37-year-old male who presented with a newly symptomatic thyroglossal duct cyst. The patient presented to the infirmary with pain in the anterior neck particularly with swallowing. A midline mass was visible and palpable on examination. Subsequent neck exploration revealed a thyroglossal duct cyst filled with purulent material. Although uncommon in adults, thyroglossal duct cysts should be a part of the surgeon's differential diagnosis when presented with a neck mass. One should remember that an infected neck mass is the common presentation of thyroglossal duct cysts in adults, and the appropriate diagnostic studies need to be performed in order to best determine the diagnosis. Once diagnosed, the TDC is best treated using the Sistrunk procedure to limit recurrence.

Cystic malformations of the neck in children

The most common cystic malformations of the neck are the result of abnormal embryogenesis involving the thyroglossal duct (TGD), lymphatic primordia and the branchial apparatus. When the basic embryology of these structures is considered, a reasonable differential diagnosis-and in some cases a definitive diagnosis-can be achieved based on the location and the imaging characteristics of the cystic mass.

Imaging for thyroglossal duct cyst: the bare essentials

Thyroglossal duct cyst is the most common congenital cyst in the head and neck, and imaging features have been well documented in the literature. However, there are several practical important points to bear in mind during preoperative imaging, which are often overlooked. This review aims to summarize the imaging findings and emphasize important points for trainees and radiologists, particularly those who may encounter this lesion infrequently.

Intracranial dural venous anomalies in familial cervical cystic hygroma

This report describes a 3-year-old male with a familial cervical cystic hygroma and intracranial dural venous abnormalities consisting of a falcine sinus between the superior sagittal and the straight sinus with a rudimentary posterior part of the superior sagittal sinus; a prominent occipital sinus with narrowed transverse sinuses; and no intraparenchymal vascular abnormality. We hypothesize that a genetic factor that resulted in familial cervical cystic hygromas may also have caused the intracranial dural venous anomalies.

Carcinomas arising in multilocular thymic cysts of the neck: a clinicopathological study of three cases

AIMS

To report three cases of primary carcinoma of the neck arising in multilocular thymic cysts (MTC).

METHODS AND RESULTS

The patients were three men aged 47, 50 and 52 years who presented with a painless neck mass of several weeks' duration. The patients had no history of previous surgical procedures or of malignancy elsewhere. The tumours in all three patients were located on the right lateral side of the neck; all patients underwent complete surgical resection of the mass. Grossly, the tumours were cystic and measured between 20 and 30 mm in greatest diameter. Histologically, the tumours showed cyst walls lined by squamous epithelium. The cyst walls contained prominent germinal centres with lymphoid hyperplasia, cholesterol cleft granulomas, and scattered keratinized structures reminiscent of Hassall's corpuscles. In addition, a neoplastic cellular proliferation composed of round to oval cells arranged in sheets and originating from the lining of the cystic structures was present. The neoplastic cells showed moderate amounts of eosinophilic cytoplasm, round nuclei, and, in some areas, prominent nucleoli. Mitotic figures were easily found, and cellular pleomorphism was present in several areas. In two cases the tumours showed features of basaloid carcinoma of the thymus, while in one case the pattern was that of squamous cell carcinoma. Immunohistochemical studies for keratin showed a strong positive reaction in the tumour cells, while leucocyte common antigen strongly stained the lymphoid background. Follow-up information obtained in two patients showed them to be alive 6 months after initial diagnosis. One patient was lost to follow-up.

CONCLUSION

The cases described here represent an unusual variant of carcinoma arising in multilocular thymic cyst in the neck region.

Pediatric head and neck masses

Most neck masses in the pediatric head and neck region are benign. Congenital, developmental, and inflammatory lesions make up most of the masses in the pediatric head and neck. For example, neck masses due to inflammatory lymphadenitis are common in children because of the frequency of upper respiratory tract infections. Although many of the malignant tumors in children are found in the head and neck, they account for only a small portion of the neck masses. The choice of the imaging modality is based on a number of factors, several of which are unique to the pediatric population. Although the bulk of disease entities are adequately evaluated by CT, MRI can provide additional vital information in many cases. MRI provides better soft tissue characterization than CT, has multiplanar capabilities. In this article, we will attempt to provide an overview of conditions that present as neck masses.

Lingual Thyroid

A case report is presented in which magnetic resonance imaging, nuclear medicine, and ultra-sound were used to diagnose a lingual thyroid and exclude a thyroglossal cyst.

Acute neck infections: prospective comparison between CT and MRI in 47 patients

PURPOSE

The purpose of this work was to assess the advantages and disadvantages of MRI versus CT in the initial evaluation of acute infections involving the neck.

METHOD

We prospectively evaluated 47 patients with neck infections. All patients underwent CT and MRI with contrast of the area of interest using similar slice thickness. Final diagnosis was achieved by percutaneous aspiration, surgical exploration and drainage, or follow-up after successful antibiotic therapy in all patients. Two radiologists reviewed all imaging studies with special attention to lesion conspicuity, location, extension, bone involvement, source of infection (odontogenic versus nonodontogenic), and presence of gas and/or calcium in the lesions. A 3 point scale was used to grade these parameters, and statistical comparison was done using paired t test.

RESULTS

As used in our population, MRI was superior to CT in regard to lesion conspicuity, number of anatomic spaces involved, extension, and source. Additionally, although not statistically significantly, MRI detected a greater number of abscess collections. CT was superior to MRI in the detection of intralesional gas and calcium and showed fewer motion artifacts. These advantages of CT were, however, not significantly better than those of MRI.

CONCLUSION

As used in our study, MRI was considered superior to CT in the initial evaluation of neck infections. Our findings suggest that MRI may be used as the first and perhaps the only modality to initially evaluate patients with neck infections when clinically feasible.

Oral cavity and oropharynx

Cross-sectional imaging has become an essential element in the evaluation of disease processes involving the oral cavity and oropharynx. This article is an overview of the anatomy and typical pathology of the these areas. The radiologist, working in conjunction with the physical examination and the clinical evaluation of a careful head and neck surgeon, can provide information that is critical to the treatment of patients with oral cavity and oropharyngeal disease.

Imaging of cystic lesions

Cystic neck masses are varied in their histology and embryogenesis. Because neural, vascular, and lipomatous lesions may all appear cystic, a multimodality imaging approach can help identify these potential mimics. Developmental neck cysts include thyroglossal duct, thymic, and branchial cleft cysts, and teratomatous lesions or lymphangiomas. Although laryngoceles are acquired lesions, congenital anomalies (e.g., abnormally long saccules) may play a role in their formation. Lesion location is at least as important a determinant as morphology in formulating the differential diagnosis of a cystic neck mass. Midline cystic lesions are most commonly thyroglossal duct cysts, although dermoid tumors are also frequently midline. Squamous cell carcinoma metastatic to anterior triangle lymph nodes (Fig. 17), and cystic, necrotic schwanommas, can mimic the typical appearance of an infected second branchial cleft cyst. Posterior triangle lymphadenopathy and lipomatous lesions may resemble cystic hygromas. Cystic-appearing masses in the carotid space include neurogenic tumors, vascular thromboses, and carotid chain lymphadenopathy. Neural-based lesions typically occur posterolateral to the carotid artery. Necrotic lymphadenopathy may be suggested by lesion multiplicity, or by the presence of ancillary features, such as systemic symptoms, or the existence of a primary tumor. It must be emphasized that the primary role of the radiologist in head and neck imaging is to help stage disease and guide surgery. Despite clinical and radiographic analysis, the diagnosis of many lesions ultimately depends on image-guided or excisional biopsy.