Oral cavity & oropharynx
Benign epithelial tumors & processes
Squamous papilloma
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PubMed Search: Squamous papilloma[TIAB] oral
Table of Contents
Definition / general | Essential features | ICD coding | Epidemiology | Sites | Etiology | Clinical features | Diagnosis | Prognostic factors | Case reports | Treatment | Clinical images | Gross description | Gross images | Microscopic (histologic) description | Microscopic (histologic) images | Molecular / cytogenetics description | Sample pathology report | Differential diagnosis | Board review style question #1 | Board review style answer #1 | Board review style question #2 | Board review style answer #2Cite this page: Stojanov IJ. Squamous papilloma. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/oralcavitysquamouspapilloma.html. Accessed April 24th, 2024.
Definition / general
- Common, small, benign intraoral squamoproliferation
- Most common papillary lesion of oral cavity
Essential features
- Common, small (< 1.0 cm), benign intraoral squamoproliferation
- Associated with HPV 6 and 11 in approximately 50% of cases
- Commonly involves soft palate, tongue, lips, tonsils
- Excisional biopsy curative with recurrences rare; no known association with oral or oropharyngeal squamous cell carcinoma
- Squamous cell papilloma represents WHO 4th edition head and neck preferred nomenclature; however, in practice, squamous papilloma is commonly used
ICD coding
Epidemiology
- Most frequently seen in third to fifth decades (Oral Surg Oral Med Oral Pathol 1980;49:419)
- Can occur at any age
- No gender predilection
Sites
- Soft palate / uvula, tongue, lips, gingiva most common intraoral sites (Semin Diagn Pathol 2015;32:3)
- Also may occur in oropharynx, larynx
Etiology
- Approximately 50% associated with HPV 6 and 11 (Eur Arch Otorhinolaryngol 2017;274:3477)
- Not associated with high risk HPV infection
- Remaining cases may represent persistence of papillary epithelial architecture following viral clearance or may represent nonspecific epithelial alteration
- No evidence of clonality
Clinical features
- Majority < 1.0 cm in size and do not show persistent growth
- In setting of immunosuppression, may be larger, multifocal, less obviously papillary, more aggressive clinically (J Oral Maxillofac Surg 2018;76:128)
Diagnosis
- Frequently suspected clinically on basis of papillary appearance
- Excisional biopsy necessary for diagnosis
Prognostic factors
- Recurrence rate minimal and related to incomplete excision
- Since mucosal HPV infections may persist for 1 - 2 years, patient may be at mildly elevated risk for additional squamous papillomas (Lancet 2013;382:877)
- Dypslasia infrequently encountered in squamous papillomas; generally not considered premalignant condition
- No known association with oral or oropharyngeal squamous cell carcinoma
Case reports
- 5 year old girl with recurrent palate papilloma (Niger J Clin Pract 2018;21:1674)
- 10 year old girl with hard palate mass (Int J Clin Pediatr Dent 2018;11:244)
- 14 year old boy with hard palate mass (Indian J Dent 2014;5:211)
- 21 year old man with uvula lesion causing sore throat (Malays Fam Physician 2019;14:74)
- 43 year old man with lesion causing airway obstruction during conscious sedation (Anesth Prog 2017;64:168)
Treatment
- Excisional biopsy
Clinical images
Contributed by Ivan J. Stojanov, D.M.D., M.M.Sc.
Squamous papilloma of gingiva
Squamous papilloma of tongue
Squamous papilloma of soft palatal mucosa
Gross description
- Papillary (cauliflower-like) and exophytic, tan-white lesion
Gross images
Images hosted on other servers:
Hard palate tumor
Microscopic (histologic) description
- Papillary proliferation of stratified squamous epithelium with variable hyperkeratosis or parakeratosis (Oral Surg Oral Med Oral Pathol 1980;49:419)
- Hyperplasia and mitotic activity restricted to basal / parabasal layers
- Retention of cellular polarity and normal maturation in suprabasal layers
- Papillary (finger-like) projections exhibit prominent fibrovascular cores
- Hyalinization at tips of cores may be seen occasionally
- Often pedunculated but may be sessile
- Koilocytes rare / absent
- No endophytic component
- Secondarily traumatized squamous papillomas may show spongiosis, leukocyte exocytosis and absence of surface keratinization
- Dysplasia in squamous papilloma characterized by cytologic abnormalities typical for epithelial dysplasia
Microscopic (histologic) images
Contributed by Ivan J. Stojanov, D.M.D., M.M.Sc.
Pedunculated
Sessile
Irritated
Fibrovascular cores
Tangentially sectioned
Tangentially sectioned
Hyalinization
Irritated
Mitotic activity
With acanthosis
Molecular / cytogenetics description
- HPV ISH not routinely performed for diagnosis
Sample pathology report
- Right soft palate, mucosa, excision:
- Squamous papilloma
Differential diagnosis
- Verruca vulgaris:
- Hyperkeratosis with marked hypergranulosis including large keratohyaline granules
- Axial inclination of rete ridges
- Rarely pedunculated and attached to underlying epithelium by narrow stalk
- Relatively uncommon in oral cavity
- Condyloma acuminatum:
- More significant epithelial hyperplasia
- Bulbous rete ridges, blunted tips of individual papillae
- Koilocytes always seen
- Relatively uncommon in oral cavity and clinical correlation beneficial
- Giant cell fibroma:
- Nodular proliferation of densely collagenous fibrovascular tissue
- Lage stellate and occasionally multinucleated fibroblasts present, particularly in superficial lamina propria
- Surface epithelium thinly keratinized and frequently papillary
- Rete ridges often elongated and occasionally anastamosing
- Verrucous hyperplasia:
- Verrucous epithelial architecture with surface keratosis representing dysplastic phenotype
- Epithelial dysplasia may or may not be present
- Epithelium often atrophic but may be hyperplastic
- Hyperkeratosis / parakeratosis and verrucous architecture often sharply demarcated
- No true fibrovascular cores
- May or may not be seen in setting of proliferative (verrucous) leukoplakia
- Verrucous carcinoma:
- Generally indolent histopathologic variant of squamous cell carcinoma
- Verrucous architecture with prominent hyperkeratosis / parakeratosis
- Endophytic growth pattern involving deep lamina propria or skeletal muscle in the absence of frank invasion
- Minimal to modest epithelial atypia / dysplasia
- Focal epithelial hyperplasia (Heck disease):
- Often multifocal
- Epithelial hyperplasia with subtle to absent papillary features
- Mitosoid bodies characteristic: karyorrhectic cells with fragmented chromatin
- Inflammatory papillary hyperplasia:
- Reactive condition exclusively seen in denture wearers or mouth breathers
- Generally presents as diffuse involvement of hard palatal mucosa
- Nodular / papillary proliferation of fibrovascular tissue
- Variable lymphoplasmacytic infiltrate
- Epithelium exhibits leukocyte exocytosis and spongiosis
- Pseudoepitheliomatous hyperplasia may be present
Board review style question #1
A 45 year old man presents with a subcentimeter lesion of the soft palatal mucosa, for which a representative image from the excisional biopsy is shown above. Which HPV types are associated with this condition?
- 2 and 4
- 6 and 11
- 13 and 32
- 16 and 18
Board review style answer #1
Board review style question #2
Which is the most common papillary lesion in the oral cavity?
- Condyloma acuminatum
- Squamous cell papilloma
- Verruca vulgaris
- Verrucous hyperplasia
Board review style answer #2
