Presentation on theme: "Dr.K.Kuberan M.S Professor of surgery Govt.Royapettah Hospital."— Presentation transcript:
Dr.K.Kuberan M.S Professor of surgery Govt.Royapettah Hospital
PAROTID GLAND Largest salivary glands lying largely below the external acoustic meatus between mandible and sternocleidomastoid muscle and it also projects forwards on the surface of masseter
Ectodermal in origin Each parotid is developed during 5 th week from angle of primary oral fissure. The groove is converted into tube which forms duct and opens into angle of primitive mouth.
With the growth of maxillary and mandibular process the duct opening is shifted to vestibule opposite the upper 2 nd molar tooth. During development the gland lies in between the branches of facial nerve, as development progresses it envelopes the branches.
Superficial part(80%)lies over posterior part of ramus of mandible Deep part(20%) lies behind mandible and medial pterygoid Facial nerve lies between them
The gland has a capsule of its own of dense connective tissue but is also provided with a false capsule by investing layer of deep cervical fascia.
Skin Superficial fascia Superficial lamina of investing layer of deep cervical fascia Great auricular nerve (anterior ramus of C2 and C3)
Mandibular ramus, Masseter and medial pterygoid muscles
Mastoid process Styloid process Carotid sheath with its contained neurovasculature (Common and Internal Carotid artery, Internal Jugular vein, vagus nerve)
Superior pharyngyeal constrictor muscle
From lateral to medial Facial nerve Retromandibular vein (Patey's fascio venous plane) External Carotid artery
External carotid artery Retromandibular vein
Superficial and deep group of parotid lymph nodes. Efferents from these nodes drain into jugulodigastric group of deep cervical nodes
Parasympathetic – stimulates watery secretion Sympathetic – stimulates mucus rich thick secretion and also vasomotor
Also known as Stensens duct Appears at the anterior part of upper border of gland and passes across masseter to traverse buccal fat and buccinator. Runs obliquely forwards for a short distance between buccinator and the oral mucosa and opens upon a small papilla opposite upper 2 nd molar tooth.
Infections – Very painful due to unyielding nature of capsule. Retrograde bacterial infection may occur from mouth via duct.
Striated ductoncocytic tumors Acinar cellsacinic cell carcinoma Excretory Ductsquamous cell and mucoepidermoid carcinoma Intercalated duct and myoepithelial cellspleomorphic tumors
Most common parotid neoplasm Median ageFifth decade Common in females Usually unilateral Slow growing mass(80%) Lobular Not well encapsulated Malignant degeneration (2-10%)
Mobile Nontender Firm Solitary mass in parotid region Raised ear lobule Obliteration of retromandibular groove Cannot be moved above zygomatic bone Deviation of uvula & pharyngeal wall towards midine if deep lobe involved No facial nerve involvement
Greyish white in color with possible cyst formation and haemorrhage.
Mixture of epithelial, myoepithelial and stromal components Epithelial cells: nests,sheets, ducts, trabeculae Stroma: myxoid, chrondroid, fibroid, osteoid No true capsule Tumor pseudopods
Arise from deep lobe Swelling in the lateral wall of pharynx Soft palate displaced to opposite side
Rapid increase in size Pain and nodularity Involvement of skin & ulceration Involvement of masseter Involvement of facial nerve Involvement of neck lymph node
2-4% of all salivary gland neoplasms 4-6% of mixed tumors 6 th -8 th decades Parotid > submandibular > Minor salivarygland Risk of malignant degeneration 1.5% in first 5 years 9.5% after 15 years Presentation Longstanding painless mass that undergoes sudden enlargement
Second most common benign parotid tumour (5%) Most common bilateral benign neoplasm of parotid. Common in lower pole Slow-growing, painless mass Marked male predominance Sixth and seventh decade Hot spot in Tc99 scan Malignant transformation rare.
Encapsulated Smooth/lobulated surface Cystic spaces of variable size, with viscous fluid, shaggy epithelium Solid areas with white nodules representing lymphoid follicles
Papillary projections into cystic spaces surrounded by lymphoid stroma Epithelium: double cell layer Luminal cells Basal cells Stroma: mature lymphoid follicles with germinal centers
May represent heterotopic salivary gland epithelial tissue trapped within intraparotid lymph nodes
Trismus => advanced disease with extension to masticatory muscles or less commonly invasion into TM joint Dysphagia => tumour of deep lobe of parotid Ear pain=>extension into auditary canal Numbness along Trigeminal nerve =>neural invasion
Hard mass in parotid region Skin ulceration/fixation Fixation to adjacent structures Examination of external auditary canal for tumor extension Regional lymph adenopathy Blood or pus from stensens duct Bulging of lateral pharyngeal wall or soft palate
Most common salivary gland malignancy 5-9% of salivary neoplasms Parotid 45-70% of cases Palate 18% 3 rd -8 th decades, peak in 5 th decade F>M
Slow growing tumors Limited local invasiveness Low metastatic potential High grade behave like SCC, low grade behave like benign tumors Sucessfully treated by adequate radical excision
Gross pathology Well-circumscribed to partially encapsulated to unencapsulated Solid tumor with cystic spaces
Areas of mucous secreting cells Epidermoid and epithelial cells
Poorly encapsulated infiltrating tumors Propensity to spread along nerves Highly invasive but may remain quiescent for a long time Highest incidence of distant metastasis Lung metastasis are most frequent. Poor prognosis
They can arise within a preexisting benign pleomorphic adenoma (CARCINOMA EX PLEIOMORPHIC ADENOMA) They may arise denovo (CARCINOSARCOMA)
Intermediate grade malignancy Low malignant potential May be bilateral or multicentric Rarely metastasize May spread along perineural planes
Most commonly in elderly females Usually Non-Hodgkins 5-10% of patients with warthins Enlarged parotid with a rubbery consistency Enlarged regional lymph nodes
Ultrasound FNAC is the diagnostic MRI is superior in demonstrating benign tumors than CT CT scan/MRI identifies regional lymph node involvement/ extension into deep lobe / parapharyngeal space PET may be useful in assessing malignant tumors
Efficacy is well established Safe, well tolerated Accuracy = 84-97% Sensitivity = 54-95% Specificity = 86=100%
First line of management superficial lobe is involved, superficial conservative parotidectomy If deep lobe(dumb bell) also involved, total parotidectomy with preservation of facial nerve. Enucleation should be avoided as recurrence rate is high Extracapsular enucleation-warthins tumor
RADICAL PAROTIDECTOMY Removal of the entire gland,facial nerve and regional lymph nodes Resection of all involved structures
positive malignancy nodes high grade tumors local invasion recurrent tumors if no h/o previous neck dissection deep lobe tumors