PROF PALANI MS FICS

Paired salivary glands that lie below the mandible on either side. larger superficial and a smaller deep lobe. Drained by a single submandibular duct (Wharton’s duct). It drains into the anterior floor of the mouth at the sublingual papilla.

3 NERVES—Marginal mandibular branch of facial nerve __hypoglossal nerve __lingual nerve 2 MUSCLES__mylohyoid __hyoglossus 1 ARTERY __facial artery.

most common ectopic salivary tissue is the Stafne bone cyst. asymptomatic, clearly demarcated radiolucency of the angle of the mandible. Formed by invagination into the bone on the lingual aspect of the mandible of an ectopic lobe of the juxtaposed submandibular gland. No treatment required.

Acute, Chronic or Acute on Chronic. Acute submandibular sialadenitis: - Viral : The paramyxovirus (mumps). - bacterial : secondary to obstruction.

most common cause is stone formation. Eighty per cent of all salivary stones occur in the submandibular glands because their secretions are highly viscous. Eighty per cent of submandibular stones are radio- opaque and can be identified on plain radiography.

SYMPTOMS: Acute painful swelling in the region of the submandibular gland, precipitated by eating. Swelling occurs rapidly and often resolves spontaneously over 1–2 hours after the meal is completed—complete obstruction. Minimal discomfort and swelling, not confined to mealtimes—partial obstruction.

SIGNS: enlarged firm submandibular gland, tender on bimanual examination. Pus may be visible, draining from the sublingual papilla.

TREATMENT: DISTAL TO LINGUAL NERVE: -- INTRAORAL APPROACH. PROXIMAL TO LINGUAL NERVE: -- gland excision, stone removal and duct ligation.

Incision and exposure of gland Gland mobilisation. Dissection of the deep lobe and identification of the lingual nerve. Wound closure.

Incision should be marked at least 3–4 cm below the lower border of the mandible to avoid damage to the marginal mandibular branch of the facial nerve. Superficial veins, including the anterior facial vein, require ligation.

intracapsular dissection - inflammatory conditions extracapsular dissection -tumours.

Important landmark in submandibular gland dissection is the posterior border of the mylohyoid muscle. The gland is retracted inferiorly, invariably attached to the lingual nerve through parasympathetic secretor motor fibres. Lingual nerve preserved. Duct ligated and gland excised.

Three cranial nerves are at risk during removal of the submandibular gland: 1 The marginal mandibular branch of the facial nerve. 2 The lingual nerve. 3 The hypoglossal nerve.

1. Haematoma; 2. wound infection; 3. marginal mandibular nerve injury; 4. lingual nerve injury; 5. hypoglossal nerve injury; 6. transection of the nerve to the mylohyoid muscle producing submental skin anaesthesia.

Only 50% of submandibular gland tumours are benign, in contrast to 80–90% of parotid gland tumors. In many circumstances, the swelling cannot, on clinical examination, be differentiated from submandibular lymphadenopathy. Most salivary neoplasms, even malignant tumours, are often slow-growing, painless swellings.

ENVIRONMENTAL : Radiation (ionising & UV radiation). EBV. Silica dust. Early menarche & nulliparity. Smoking (Warthin’s tumor). Diet rich in PUFA (protective) GENETIC.

most common benign tumor of both major & minor salivary glands. Peak incidence 4 th & 5 th decade with slight female preponderance.

Epithelial & modified myoepithelial cells intermingle with a stroma can be mucoid, myxoid, fibrous or chondroid. Areas of oncocytic metaplasia are common & it can be misdiagnosed as oncocytoma. Most characteristic appearance of stroma is the formation of mucoid or myxochondroid areas containing scattered epithelial cells with cartilaginous or osseous metaplasia.

Principal clinical problem is recurrence (3.4 % in 5 yrs – 6.8 % in 10 yrs) and malignant progression. RISK FACTORS FOR RECURRENCE : Variable / Absent capsulation. Intracapsular invasion. Improper excision.

MC malignant tumor of salivary gland.. Low grade : predominance of mucous secreting cells with well differentiated epidermoid cells. High grade : few or no mucous producing cells and poorly differentiated epidermoid cells.

15 % of salivary neoplasms. 2 nd most common malignant tumor of salivary glands. MC malignant tumor in submandibular, sublingual & minor salivary glands. Peak incidence 5 th & 6ht decade. MC site : oral cavity (50%) sinonasal tract (18%)

5 – 11 % of malignant tumors of salivary glands. Presents at a younger age. Affects women > men. Arises MC in parotid. MICROSCOPY : cells with basophilic cytoplasm associated with lymphoid infiltrate. Subtypes : solid, microcystic, papillary cystic & follicular

Represents malignancy with both epithelial & mesenchymal elements. 3 – 12 % of salivary gland tumors. Carcinoma ex pleomorphic adenoma - arising from pre exsisting pleomorphic adenoma. Malignant & metastatic components are epithelial in origin. De novo malignant mixed tumor (CARCINOSARCOMA) : with malignant features of both epithelial and mesenchymal components

Con………………. malignant transformation occurs in 3 – 4 % of all benign mixed tumors. Risk of malignant transformation of pleomorphic adenoma increases with duration of disease. ( 1.5% within 5 yrs - 9.5% within 15 yrs). Features of malignancy in pleomorphic adenoma Necrosis, calcification, hemorrhage and excessive hyalinization.

Clinical features of malignant submandibular tumours 1. Rapid enlargement of the swelling. 2. Induration and/or ulceration of the overlying skin. 3. Cervical node enlargement. 4. Ipsilateral weakness / numbness of tongue. 5. Fixity to mandible.

FNAC [ sensitivity : 85 – 99 % specificity : 96 – 100% ] Open surgical biopsy is contraindicated. Trucut biopsy-inoperable tumor -lymphoma.

CT better for identifying bone destruction of mandible. MRI is better to detect - bone marrow involvement. - perineural spread. - parapharyngeal space involv. OTHERS : PET scan, color doppler sonography.

PRIMARY TUMOR (T) : Tx primary tumor cannot be assessed T0 no evidence of primary tumor T1 tumor <2cms without extraparenchymal extension T2 tumor >2cms but not >4cms without extraparenchymal exten. T3 tumor >4cms and / or extraparenchymal extension. T4 tumor invades skin, mandible.

REGIONAL LYMPH NODES (N) Nx nodes cannot be assessed N0 no nodal metastasis N1 single ipsilateral LN <3cms N2a single ipsilateral LN >3cms but <6cms N2b multiple ipsilateral LN <6cms N2c bilateral / contralateral LN < 6cms. N3 LN >6cms

METASTASIS : Mxdistant metastasis cannot be assessed M0 no distant metastasis M1distant metastasis

STAGE I T1,2 N0 M0 STAGE II T3 N0 M0 STAGE III T1,2 N1 M0 STAGE IV T4 N0 M0 T3,4 N1 M0 ANY T N2 M0 ANY T N3 M0 ANY T ANY N M1

SURGERY RADIOTHERAPY CHEMOTHERAPY

Tumours, surgical excision with a cuff of normal tissue is the goal. suprahyoid neck dissection, preserving the marginal mandibular branch of the facial nerve, lingual nerve and hypoglossal nerves. In cases of overt malignancy, modified neck dissection or radical neck dissection is appropriate.

RR ECURRENT ESIDUAL ERFACTORY

ADENOMA T1 – T2 MALIG LOW GRADE T3 – T4 TUM. HIGH GRADE CLOSE MARGIN DEEP LOBE PERINEURAL SPREAD INTRAVASCULAR INV N+ NO RT GIVE RT

RADIOTHERAPY TELE THERAPY + / - BRACHYTHERAPY DOSE Gy NERVE GRAFT IS NOT C/I FOR RT RT TO IPSILATERAL NECK

COMPLICATIONS : Severe xerostomia Sensory neural hearing loss Osteo necrosis of mandible.

NO ROLE IN ADJV. SET. USED SPARINGLY IN  METS UNRESECTABLE DRUGS  ADR PLAT 5-FU

Stage. Histology & grade. Site. Lymph node metastasis. Surgical margins Perineural spread. Dedifferentiation. (detrimental outcome)

TUMOR SUPPRESSOR GENES & ONCOGENES POOR PROGNOSTIC INDICATORS : point mutation of TP 53 tumor suppressor gene activation of c-myc & ras p 21 proto oncogene low p 27 tumor suppressor gene expression over expression of c-erb b2 amplification of Her-2 / Neu expression DNA PLOIDY aneuploidy poor prognostic indicator

MEC – MUC 1, MUC 4, MUC 5AC, MUC 5B SAG (salivary agglutinin) MASPIN CEA – glandular & highly diff. squamous cell ca. LACTOFERRIN – glandular tumors AMYLASE – ACC PREKERATIN & VIMENTIN – pleomorphic adenoma