Section 9

32-year-old complaints recurrent pain and swelling associated with eating in the right submandibular gland region.

What is the most likely diagnosis? List two differential diagnoses.

  • Right submandibular sialadenitis
  • Right submandibular sialolithiasis

How would you manage this?

  • Regular sialogogues
  • Increase hydration
  • Antibiotics if evidence of acute infection
  • Surgery 
    • Marsupialisation of submandibular duct
    • Sialendoscopy
    • Submandibular gland excision

Describe the parasympathetic supply to the submandibular gland?

Pre-ganglionic parasympathetic secretormotor fibres arise from superior salivary nucleus of the facial nerve and travel via facial nerve and chorda tympani to join lingual nerve (branch of mandibular branch of the trigeminal nerve) to submandibular ganglion. From here the postganglionic sympathetic fibres run along the duc to the submandibular gland.

What further investigations might you request?

  • Ultrasound neck
  • MR sialogram

Name three nerves that could be injured during a submandibular gland excision.

  • Lingual nerve
  • Hypoglossal nerve
  • Marginal mandibular gland

Supporting Information

Submandibular gland– divided into deep and superficial, by posterior mylohyoid. Mixed gland (serous and mucus). The submandibular duct (wharton’s duct) emerges from the deep gland. It enters the floor of the mouth next to the frenulum, it runs between mylohyoid and hyoglossus and is crossed by the lingual nerve twice. Relations:

  • Medial– mylohyoid, hyoglossus, hypoglossal nerve  (inferior to deep gland), deep lingual vein, submandibular duct (inferior to deep gland)
  • Lateral– submandibular fossa of mandible, medial pterygoid muscle and facial artery
  • Inferior, skin, platysma, facial vein, cervical facial nerve

Blood supply + lymph + Nerves

  • Arterial- facial artery
  • Vein- facial vein
  • Lymph- submandibular lymph nodes
  • Nerves
    • Parasympathetic– secretomotor fibres; reach submandibular gland via the submandibular ganglion “hitch-hiking along nerves.
    • Sympathetic– vasoconstrictors from facial artery plexus

Submandibular gland excision

  • Indications– neoplasia, drooling, recurrent infections/chronic sialadenitis, pain 
  • Incision for submandibular gland- 3 cm below angle of the mandible to avoid marginal mandibular nerve. Other nerves at risk, lingual, hypoglossal, nerve to mylohyoid. 

Complications– pain, infection, bleeding, nerve injury, failure to ligate wharton’s duct causes an extravasation retention cyst to develop as the sublingual duct of rivinus drains into distal submandibular duct. 

Infectious salivary glands: Acute sialadenitis

  • Viral
    • Mumps– paramyxovirus- 4-10yrs. Bilateral parotid swelling, malaise, trismus, orchitis, pancreatitis, nephritis, encephalitis, cochleitis and meningitis, self limiting
    • Coxsackievirus
    • HIV
    • Echovirus
  • Bacterial
    • Normally staphylococcal infection
    • Presents with pain, tenderness, duct discharge
    • Seen in dehydrated, immunocompromised patients
    • Treatment is systemic abx and rehydration

Infectious salivary gland tumours- chronic sialadenitis– recurrent, slightly painful enlargement of the gland. Due to impaired homeostasis of salivary flow. Treatment is sialogogues, massage, hydration or sialodenectomy in refractory cases. 

Infectious salivary gland tumours- granulomatous sialadenitis– TB/Sarcoid/Syphilis/HIV

Non-infective/non- neoplastic salivary gland disease

  • Sialolithiasis– seen in USS/OPG potentially and sialogram 100% diagnostic if duct cannulated.
    • Stones in glands🡪pain and swelling, worse after meals, infections–>swelling, pyrexia.
    • Common in middle aged men- normally calcium and hydroxyapatite.
      • 80% submandibular
      • 65 % of submandibular stones are radiopaque
      • 65% parotid stones radiolucent
    • Treatment:
      • Conservative– hydration, sialogogues
      • Medical interventional– lithotripsy
      • Surgical– stone excision intra-orally by widening of the duct or submandibular gland excision
    • Associated with MEN IIA with hypertension, palpitation, high calcium and renal stones. Medullary Ca, pheochromocytoma and parathyroid cancer.
  • Inflammatory conditions
    • Sjogren’s– Autoimmune- periductal lymphocytes in multiple organs. 40% salivary involvement and 1in 6 get lymphoma:
      • Primary– sicca complex- identified by xerostomia, xerophthalmia and no connective tissue abnormality
      • Secondary– identified by xerostomia, xerophthalmia and a connective tissue abnormality normally RA
      • May investigate with sublabial biopsy.
    • Benign lymphoepithelial lesion– mass of lymphoid tissue  within a gland containing scattered foci of epithelial cells of ductal origin associated with infection. 10%–>lymphoma.
  • Pseudoparotomegaly– things that may be confused with enlarged parotid:
    • Winged mandible/mandibular tumours
    • Dental cyst
    • Branchial cyst
    • Hypertrophic masseter
    • Facial nerve neuroma
    • Preauricular lymph node
    • Lipoma
    • Seb cyst
  • Drug induced sialomegaly- TOPIC
    • Thiouracil
    • OCP
    • Phenylbutazone
    • Isoprenaline
    • Co-proxamol
  • Metabolic causes of sialomegaly
    • Diabetes
    • Myxoedema
    • Cushing’s- hypercortisolism
    • Cirrhosis
    • Gout
    • Alcoholism
    • Bulimia
  • Sialectasis-unknown aetiology, progressive destruction of the alveoli and parenchyma of the gland. It causes duct stenosis and cysts to form. Calculi may be seen and present in a similar way. 

Investigations for salivary gland conditions– ESR, FBC, RF, ANA, electrophoresis, anti Ro and soluble liver antibodies, TFTs, BM, LFTs, urate, plain film, sialogram, CT/MRI if malignant disease suspected. FNA (don’t do incisional/trucut biopsy due to seeding). 

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