HIV Infection INFECTION DWI Fig Axial CT and MRI images show multiple enlarged lymph nodes in the neck as well as in the parotid gland bilaterally. These nodes were suppurative with positive diffusion. Salivary gland involvement in HIV is well recognized and is seen more commonly on children. Wide spectrum of imaging findings may be seen: bilateral enlargement of the parotid gland, bilateral enlarged lymph nodes and benign lymphoepithelial lesions / cyst (BLL). BLL and HIV are seen as multiple cyctis and solid masses enlarging both parotid gland and is commonly associated with tonsilar hyperplasia and cervical reactive adenopathy.
Ranula INFECTION Fig Axial and reformated images show large ranula filling sublingual space with narrowing of the anterior isthmus Mucocele / retension cyst: results from partial obstruction of a salivary duct. Obstruction may be due to a calculus, stricture, surgery or accidental trauma. Mucocele most commonly arise from SMG. Lesion in the sublingual region is called Ranula. When the mucocele extend to the SMG space around the posterior border of the mylohyoid muscle it is known as plunging ranula. Simple ranula are oval lenticular shape and shows low density on CT. Fig Axial and sagittal images ranula in the sublingual space without extension in the submandibular space.
Plunging Ranula INFECTION mylohyoid muscle Diving Ranula Fig CECT shows a diving ranula originating in the left SL space passing through mylohyoid muscle to extend into anterior and posterior submandibular space. Diving ranula / extravasation psuedocyst is a term used when a simple ranula becomes large, ruptures out of posterior sub lingual space into sub mandibular space lacking epithelial lining. On imaging it shows a tail collapsed in the SLS with a large oval shaped component in the SMS. Microscopically simple ranula have a epithelial lining while the diving ranula is without and is a psuedocysst. Most common clinically presentation is painless swelling in the SMS. 50% have history of trauma.
SARCOIDOSIS INFLAMMATORY Fig CECT shows bilateral heterogenous enlargement of the parotid gland with multiple hypodensities. Patient also showed bilateral mediastinal lymphadenopathy. Sarcoidosis is a multi-system granulomatous disease characteristically causing bilateral hilar lymphadenopathy. Parotid gland swelling has been reported in 4 to 6 percent of patients diagnosed with sarcoidosis. The most common pattern is represented by major salivary gland swelling, and xeorstomia. Sarcoidosis may present with uveoparotid fever, or Heerfordt s syndrome, which consists of a triad bilateral parotid swelling, uveitis and cranial nerve involvement. Confirmation of diagnosis can be established on the cumulative basis of the patient s medical history, clinical examination results, chest radiographic findings, elevated serum ACE levels and the results of a microscopic examination.
SIALOLITHIASIS Fig CECT shows intra-glandular calculus in right SMG with inflammation of the gland and mild dilatation of the duct. Fig CECT shows bilateral parotid calculi with dilatation of right ductal system (green arrow). Obstructive sialadenitis: is most commonly caused by stones. Obstruction causes stasis, inflammation and infection. 80% of the calculi occur in submandibular gland of which 80% are radioopaque. SMG is more prone for gland/ duct calculi due to a) the alkaline and viscous composition of the saliva, b) the high concentration of calcium, mucin, and phosphate ions in secretions c) the longer course and angulation of Wharton's duct which causes slower salivary flow rates. US is almost 94% sensitive.
SIALOLITHIASIS Fig CECT shows right SMG gland and duct calculi (yellow arrow) with abscess formatioon (green arrow). Fig CECT shows right Wharton s duct calculus without ductal dilatation (yellow arrow). The complication of calculus disease include ductal stricture, acute and chronic sialadenitis, glandular atrophy, secondary infection, mucoceles and Kutter tumor.
OBSTRUCTIVE SIALADENITIS (A) (B) Fig Obstructive Sialolithiasis Sagittal reconstructed axial CT images show dilatation of the right submandibular duct (blue arrow) due to (A) anterior floor of the mouth squamous cell carcinoma (yellow arrow) (B) Submandibular abscess and duct obstruction from tongue base cancer (red arrow). Secondary SMG sialadenitis maybe seen either due to inflammation surrounding the duct or due to direct ductal invasion leading to secondary obstruction from the anterior floor of the mouth malignancies like squamous cell carcinoma. Swollen SMG is often mistaken for malignant node. Contrast enhanced CT scan is more sensitive than ultrasound in identifying the primary. Bimanual palpation of the floor of the mouth maybe helpful.
AUTOIMMUNE SJOGREN S SYNDROME Fig Sjogren s Syndrome: CECT reveals classical imaging findings of later stages of SJS with bilateral enlargement, heterogenicity and increase CT density of the parotis gland. Doppler USG shows increased vascularity. Primary Sjogren s syndrome is an autoimmune disease affecting the major and minor salivary glands with or without lacrimal gland involvement causing xerostomia and xerophthalmia. Sjögren syndrome is a chronic autoimmune disorder characterized by xerostomia (dry mouth), xerophthalmia (dry eyes), and lymphocytic infiltration of the exocrine glands. This triad is also known as the sicca complex. 90% affected are females. The diagnosis is based on clinical features and labial minor gland biopsy with detection of autoantibodies such as anti-ro/ anti-ss-a and anti-la/anti-ss-b.
TRAUMA Fig Contusion and rupture of right submandibular gland from trauma. Among all the salivary gland, parotid gland is injured most commonly due to its superficial location as compared to SMG which is protected by mandible. Blunt injury is most common and result in edema, contusion, hemorrhage and hematoma. Penetrating injury may result in laceration of ducts and parenchyma and injury to facial nerve within parotid gland. In addition ill-fitting dentures and repeated cheek biting cause injury to the duct orifice. Calcification from old trauma are not uncommon.
CYSTIC LESIONS Any pathology of the salivary gland may present as cystic lesion on imaging, most commonly congenital and infective. Tumors are very rarely cystic. Most common cystic lesions seen are: BCC=Branchial Cleft Cyst BCC I BCC II Ranula Lymphoepithelial Lesions in HIV+ SJOGREN S SYNDROME
VASCULAR LESIONS Introduction: Most of the vascular anomalies are congenital and do not arise from salivary gland tissue but may involve it intimately. And therefore when vascular anomalies are treated surgically, the involved salivary gland is frequently removed. Parotid is the commonest salivary gland involved. Treatment depends on type and extent of the malformation for example Hemangiomas eventually regress during childhood whereas vascular malformations continue to grow and therefore requires treatment. Arteriovenous malformations are destructive and life threatening and must be surgically resected; however, the goal of treatment for venous and lymphatic malformations may be to control the disease rather than to cure it. Classification of vascular lesions Hemangiomas infantile hemangioma, rapidly involuting congenital hemangioma (RICH), non-involuting congenital hemangioma (NICH). Vascular malformations Venous Capillary (port-wine stains) Lymphatic (cystic hygromas) Arteriovenous Mixed Venous-lymphatic Venous venular
HEMANGIOMAS VASCULAR LESIONS Hemangiomas are congenital vascular tumors comprised of proliferative capillary tissues that are related to placenta. These are most common parotid gland tumors of infancy (girls > boys). In half of the pts swelling regresses by third year of life while 50% may undergo a rapid proliferative phase and can greatly increase in volume. On MR they exhibit intermediate T1 and high T2 signal and may show flow void and phleboliths (Ca++).
HEMANGIOMAS VASCULAR LESIONS Besides commonly seen infantile hemangioma, there are two other types of hemangiomas a) rapidly involuting congenital hemangioma (RICH), and b) noninvoluting congenital hemangioma (NICH). The rapidly involuting hemangiomas will frequently be quite large at birth but the mass completely disappears within several months. Usually, residual scarring of the skin with atrophy of the subcutaneous tissues is all that remains. Hemangiomas can leave a very disfiguring residual in a large percentage of patients, and may take years to involute. Therefore, today there are various treatment options (Observation, Steroid therapy(intra lesional injection), vincristine and interferon, pulsed dye laser). available and specific treatment regimens depends on extent of the hemangioma. If the hemangioma remains large at the age of approximately 3 4 years, then surgical removal is indicated to provide the child with facial symmetry. Surgery can be difficult and frequently involves substantial blood loss and a risk to the facial nerve.
LYMPHATIC MALFORMATIONS VASCULAR LESIONS Lymphatic malformations are slow flow malformations consisting of ectatic lymph channels. Cyst may be micro(<2 cm) or macrocystic (>2 cm) in diameter. They are quite extensive with the parotid and SMG spaces frequently involved. These lesions are usually present at birth and tends to grow slowly through-out the patient s lifetime with exacerbated growth in infection, trauma and hormonal changes. Lesions never involute and therefore, intervention (surgery and sclerotherapy) becomes necessary to preserve functions.