Mouth Lumps and Marks

Mouth lumps and marks can be unfamiliar territory – partly because it is rarely an area of expertise for many GPs, and partly because many mouth problems are picked up by, or presented to, dentists in the first place. A proportion of patients will choose a GP as the first port of call, so a working knowledge of the area is useful.

Published: 2nd August 2022 | Updated: 15th August 2022

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

Likely: None.

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.
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Website disclaimer

Pulse Reference is based on the best-selling book Symptom Sorter.

The experts behind Pulse Reference are Dr Keith Hopcroft who is the co-author of Symptom Sorter, a GP in Essex and Pulse’s editorial advisor and Dr Poppy Freeman, a GP in Camden and also a clinical advisor to Pulse.

This website is for clinical guidance only and cannot give definitive diagnostic information. Practitioners should work within the limits of their individual professional practice, seek guidance when necessary and refer appropriately.