Tuberculosis in the head and neck--a forgotten differential diagnosis.

The aim of the present review is to illustrate the pathogenesis and imaging findings of tuberculosis in specific head and neck regions to avoid pitfalls in diagnosis. It is imperative to be aware of, and provide an early diagnosis for, extra-pulmonary tubercular lesions in the head and neck. A high index of suspicion combined with an appropriate clinical setting serves as an important background to diagnose tubercular lesions in the head and neck region and differentiate them from malignancy and other disease entities. Early diagnosis and treatment can prevent irreversible and debilitating complications and mortality from disseminated tuberculosis.

Imaging of salivary gland tumours.

Salivary gland neoplasms account for <3% of all tumors. Most of them are benign and parotid gland is the commonest site. As a general rule, the smaller the involved salivary gland, the higher is the possibility of the tumor being malignant. The role of imaging in assessment of salivary gland tumour is to define intra-glandular vs. extra-glandular location, detect malignant features, assess local extension and invasion, detect nodal metastases and systemic involvement. Image guided fine needle aspiration cytology provides a safe means to obtain cytological confirmation. For lesions in the superficial parotid and submandibular gland, ultrasound is an ideal tool for initial assessment. These are superficial structures accessible by high resolution ultrasound and FNAC which provides excellent resolution and tissue characterization without a radiation hazard. Nodal involvement can also be assessed. If deep tissue extension is suspected or malignancy confirmed on cytology, an MRI or CT is mandatory to evaluate tumour extent, local invasion and perineural spread. For all tumours in the sublingual gland, MRI should be performed as the risk of malignancy is high. For lesions of the deep lobe of parotid gland and the minor salivary glands, MRI and CT are the modalities of choice. Ultrasound has limited visualization of the deep lobe of parotid gland which is obscured by the mandible. Minor salivary gland lesions in the mucosa of oral cavity, pharynx and tracheo-bronchial tree, are also not accessible by conventional ultrasound. Recent study suggests that MR spectroscopy may differentiate malignant and benign salivary gland tumours as well as distinguishing Warthin's tumor from pleomorphic adenoma. However, its role in clinical practice is not well established. Similarly, the role of nuclear medicine and PET scan, in imaging of parotid masses is limited. Sialography is used to delineate the salivary ductal system and has limited role in assessment of tumour extent.

A short review of basic head and neck interventional procedures in a general radiology department.

Image-guided interventional procedures provide a safe way to diagnose and treat a variety of head and neck abnormalities. The procedure time is usually short, and most procedures can be performed on an outpatient basis. Knowledge about strengths and weaknesses, efficacy, potential complications, and pitfalls of these procedures allows the best treatment to be chosen for a particular lesion type. This review discusses some of the commonly performed interventional radiology procedures in a general radiology department in the management of patients with neoplastic diseases in the head and neck region.

Imaging of cystic or cyst-like neck masses.

Cystic or cyst-like neck masses form a unique category within head and neck radiology with unique differential diagnoses. The precise anatomical location and imaging appearances are important for accurate diagnosis and formulating the differential diagnoses of cystic lesions in the neck. In vast majority of cases ultrasound, sometimes supplemented by fine-needle aspiration cytology (FNAC), is adequate for pre-treatment assessment. For large, deep-seated lesions assessment using magnetic resonance imaging (MRI) or computed tomography (CT) often provides useful supplementary information. Radiologists should be aware of imaging findings of common cystic neck masses to help in their appropriate management.

Delayed complications of radiotherapy treatment for nasopharyngeal carcinoma: imaging findings.

Radiotherapy is used to treat a wide variety of head and neck tumours that arise in and around the skull base. The delayed effects of radiation damages a range of structures, including the nervous system, bone, major vessels, mucus membranes, pituitary and salivary glands, as well as increasing the risk of radiation-induced neoplasms. In this review the complications resulting from radiation treatment for nasopharyngeal carcinoma (NPC), a cancer treated with a high dose of radiation to a fairly large region, are illustrated. Many patients with NPC have a long-term survival, so are at risk of developing delayed radiation effects, and hence may demonstrate a wide range of complications on imaging. Other tumours around the skull base treated with radiotherapy include meningiomas, chordomas, chondrosarcomas, pituitary adenomas, paranasal sinus and nasal cavity tumours. In these cases similar complications may be encountered on imaging, although the severity, incidence and location will vary.