Mouth Lumps and Marks

Differential Diagnosis

Common Diagnoses

  • Apical Tooth Abscess (Gumboil)
  • Aphthous Ulceration
  • Fordyce Spots (Tiny White or Yellow Spots, on Mucosa Opposite Molars and Vermilion Border of Lips; they are Sebaceous Glands)
  • Oral Candida Infection
  • Mucocoele (solitary Cystic Nodule Inside Lip)

Occasional Diagnoses

  • Lichen Planus
  • Trauma: Bitten Cheek
  • Ranula
  • Torus: Benign Maxillary or Mandibular Outgrowth of Bone (Very Common but Usually Asymptomatic so not Commonly Seen)
  • Premalignant Coloured Areas: Erythroplakia (Red), Leukoplakia (White), Speckled Leukoplakia (Red and White), or Verrucous Leukoplakia
  • Geographical and Hairy Tongue
  • Tonsillar Concretions
  • Other Forms of oral Ulceration (See ‘Mouth Ulcers’ Section)

Rare Diagnoses

  • Malignancy: SCC or Melanoma
  • Pachyderma Oralis (from Irritants)
  • Heavy Metal Poisoning (Lead, Bismuth, Iron): a Dark Line below the Gingival Margin
  • Cancrum Oris
  • Sublingual Dermoid Cyst
  • Sublingual Gland Tumour
  • Pigmentation due to Oral Contraceptive Pill: Black or Brown Areas Anywhere in the Mouth
  • Addison’s Disease: Bluish Hue Opposite Molars
  • Peutz–Jeghers Spots: Brown Spots on the Lips
  • Telangiectasia: May be a Sign of Osler–Weber–Rendu Syndrome
  • Stevens–Johnson Syndrome

Ready Reckoner

Key distinguishing features of the most common diagnoses

AbscessUlcerFordyce SpotsCandidaMucocoele
Lesion TenderYesYesNoPossibleNo
Flat LesionNoYesNoYesNo
Multiple LesionsNoPossibleYesYesNo
White LesionsNoYesPossibleYesNo
Lesion Scrapes OffNoNoNoYesNo

Possible Investigations


Possible:FBC, ESR, CRP, ferritin, B12 and folate, fasting glucose or HbA1c, swab of lesion, HIV test.

Small Print:Biopsy (performed at hospital).

  • FBC, ESR, CRP and HIV are useful if immune deficiency (e.g. as a background to Candida infection) is suspected; FBC and ESR or CRP may be helpful in suspected malignancy too.
  • Ferritin, B12 and folate deficiency are sometimes associated with oral aphthous ulceration – worth checking these in cases of recurrent or chronic ulceration (and see other possible investigations in ‘Mouth ulcers’ section).
  • Fasting glucose or HbA1c to investigate possible diabetes if candidal infection otherwise unexplained.
  • Mouth swab to confirm candidal infection, though a diagnostic trial of treatment is often the practical first step.
  • Biopsy: Of suspicious lesions – this is inevitably performed in secondary care.

Top Tips

  • Recurrent oral aphthous ulceration is a feature of a few systemic diseases (e.g. coeliac disease, Crohn’s disease, Behçet’s disease and AIDS) so be prepared to re-evaluate the history and widen the net of information gathering in repeat presentations.
  • It is tempting to give antibiotics for a dental abscess, but the old surgical maxim ‘if there’s pus about, let it out’ still holds true. Antibiotics may help reduce pain and surrounding infection but are only a temporary measure and may delay definitive treatment in those trying to avoid seeing a dentist, and increase the risk of complications. Encourage patients to see a dentist in the first place – offering a referral letter can be helpful and may help to overcome any possible barrier to urgent access to a dentist at the dental reception desk.
  • Always examine lumps by palpation from inside as well as outside the mouth. Wash latex gloves before the examination. Glove powder tastes foul!

Red Flags

  • Always refer the patient with permanent red or white buccal mucosal patches. Biopsy is indicated.
  • If an ulcer fails to heal within a few weeks, especially if it is painless, refer for a specialist opinion as a suspected malignancy.
  • Do not fail to examine regional lymph nodes. Enlarged nodes would be a significant finding, especially if they are non-tender and persistent.

Published: 2nd August 2022 Updated: 10th April 2024

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