Squamous Papilloma and Papillomatosis

Slide 1 · Squamous Papilloma and Papillomatosis

Laryngeal squamous papilloma and recurrent respiratory papillomatosis

Structure • HPV pathogenesis • Clinicopathologic diagnosis

Dr Abu Suraih Sakhri

MBBS, MD (Pathology)

www.abusuraihsakhri.com

Slide 2 · Learning objectives

Define laryngeal squamous papilloma and recurrent respiratory papillomatosis.

Connect HPV 6/11 to lesion distribution and recurrent disease.

Recognize exophytic fibrovascular papillae with orderly squamous maturation.

Differentiate papillomas from reactive nodules, dysplasia, and carcinoma.

Explain symptoms, management goals, and vaccine prevention.

Slide 3 · Laryngeal context: Why the site matters

Schematic — superior view of vocal folds

Glottic lumen

Papillary lesion

Lesions commonly involve the true vocal folds.

Exophytic growth on the vibrating margin distorts phonation.

Multiple lesions may also narrow the airway.

Slide 4 · Papilloma: A benign epithelial neoplasm

Benign: Orderly squamous epithelial proliferation without demonstrated invasion.

Papilloma: Outward-growing architecture forming slender projections.

Locally symptomatic does not mean intrinsically malignant.

Slide 5 · The defining gross pattern

Schematic — not a photomicrograph

Fibrovascular cores

Soft, exophytic lesion; Usually small and rarely exceeds 1 cm.

Finger-like papillae create a delicate projected surface.

Growth often arises on a true vocal fold.

Slide 6 · Solitary lesion versus papillomatosis

Feature

Solitary papilloma

Recurrent papillomatosis

Distribution

A single identifiable papilloma

Multiple or recurrent papillomas

Typical context

Often an adult

Can affect children or adults

Clinical course

Local lesion

Potentially repeated recurrences

Shared histology

Squamous fronds with fibrovascular cores

Same basic papillary architecture

Slide 7 · Anatomic extent: Larynx predominates

Larynx (usual site)

True vocal folds are common

Other upper airway sites

Multifocal respiratory disease may occur

Occasional distal airway extension

Broader RRP spectrum requires clinical assessment

Slide 8 · HPV 6 and 11 are the principal causes

Low-risk human papillomavirus types 6 and 11 drive most laryngeal papillomas.

HPV association explains the viral etiology despite benign morphology.

Virus type alone does not provide an individual recurrence forecast.

Slide 9 · Low-risk HPV is not synonymous with low morbidity

HPV 6/11 usually produces benign epithelial lesions.

Location in a narrow, functionally sensitive airway can cause serious symptoms.

Recurrence and treatment-related scarring may dominate long-term burden.

Slide 10 · HPV exposure and transmission routes

Exposure to HPV 6/11

Person-to-person contact or perinatal exposure

Infection of susceptible epithelium

Not all exposed individuals develop disease

Papillomatous proliferation

Benign but potentially recurrent growth

Slide 11 · Vertical transmission is relevant to childhood disease

Maternal genital HPV infection provides one recognized exposure pathway.

Passage through the birth canal is a plausible route in juvenile-onset disease.

Perinatal exposure does not mean that every infant will develop papillomatosis.

Mode of acquisition cannot be inferred solely from a childhood diagnosis.

Slide 12 · Adult-onset and juvenile-onset patterns

Domain

Adult pattern

Juvenile pattern

Multiplicity

Solitary papilloma is common

Multiple lesions may occur

RRP

May occur

May occur

Clinical priority

Voice symptoms; assess extension

Voice and airway compromise

Recurrence

Variable

Can require repeated procedures

Slide 13 · Recurrence is a clinical behavior, not a histologic grade

A benign papilloma can recur after endoscopic removal.

Multiple or recurring lesions support a diagnosis of respiratory papillomatosis.

Recurrence alone must not be equated with squamous carcinoma.

Slide 14 · Simplified HPV-associated lesion development

HPV infection

Infection of epithelium

Squamous cell proliferation

Epithelial thickening and maturation

Exophytic papillary growth

Fibrovascular stalks carry the surface epithelium

Slide 15 · Exophytic growth differs from stromal invasion

Architecture

Benign papilloma

Invasive carcinoma

Direction

Papillae project outward

Tumor infiltrates underlying tissue

Epithelial organization

Orderly stratification

Often disordered cytology or maturation

Stroma

Central fibrovascular cores

Desmoplastic/infiltrated tissue possible

Interpretation

Benign if no invasion

Malignant by invasive behavior

Slide 16 · Papillary fronds are the dominant microscopic clue

Schematic — not a photomicrograph

Fibrovascular cores

Multiple slender projections are visible at low magnification.

Each projection contains a central supportive stromal core.

Stratified squamous epithelium covers each frond.

Slide 17 · Fibrovascular core: Structure and function

Schematic — not a photomicrograph

Fibrovascular cores

Connective tissue provides the scaffold for each projection.

Small vessels course within the core.

The surface epithelium rests over the core rather than invading it.

Slide 18 · Orderly squamous stratification

Schematic — orderly epithelial maturation

Superficial maturation

Intermediate squamous cells

Basal / parabasal zone

Supporting stroma

Basal cells rest along the epithelial–stromal interface.

Suprabasal cells mature toward the luminal surface.

Preserved maturation supports a benign lesion when invasion is absent.

Slide 19 · Surface and basal zones: Avoid overinterpretation

Schematic — orderly epithelial maturation

Superficial maturation

Intermediate squamous cells

Basal / parabasal zone

Supporting stroma

Epithelial thickness can vary among papillary projections.

Basal/parabasal proliferation may be accentuated.

Evaluate architecture, maturation, cytology, and invasion together.

Slide 20 · Koilocytosis: A supporting HPV-related finding

Some papillomas exhibit superficial koilocytes.

Koilocytes show perinuclear clearing and characteristic nuclear changes.

The feature supports an HPV effect but is not required in every fragment.

Exophytic fibrovascular architecture remains diagnostically central.

Slide 21 · Trauma can change the appearance of a benign lesion

Papilloma on vocal-fold edge

A location exposed to vibration

Repeated mechanical contact

Friction and focal mucosal injury

Surface ulceration / bleeding

Possible hemoptysis without proving cancer

Slide 22 · Ulceration does not automatically signify malignancy

An injured papilloma can show erosion and bleeding.

Interpret ulceration with the entire epithelial pattern.

Concerning cytology or destructive infiltration still requires separate assessment.

Slide 23 · Histology: Four observations to record

Growth pattern

Exophytic slender projections

Core

Central fibrovascular stroma

Lining

Orderly stratified squamous epithelium

Interface

No evidence of infiltrative growth in sampled tissue

Slide 24 · Where pathology can mislead: Fragmented biopsies

Tangentially sectioned papillae may obscure the true projection pattern.

Small biopsy fragments may incompletely show the epithelial–stromal boundary.

Trauma can introduce reactive atypia that needs contextual evaluation.

Correlate microscopic interpretation with laryngoscopic distribution.

Slide 25 · Why small lesions cause prominent voice symptoms

Schematic — superior view of vocal folds

Glottic lumen

Papillary lesion

Voice depends on regular vocal-fold vibration.

An exophytic mass alters fold contact and vibratory symmetry.

Hoarseness can occur despite benign biology and small size.

Slide 26 · Why multiple lesions may compromise breathing

Schematic — airway cross-section

Functional narrowing

Multifocal papillomas occupy portions of the airway lumen.

Luminal narrowing increases airflow resistance.

Stridor or respiratory distress requires urgent clinical assessment.

Slide 27 · Hoarseness is the most common clinical signal

A persistent altered voice can be the first sign of laryngeal papilloma.

The site and surface burden affect phonation.

Persistent symptoms warrant laryngeal visualization rather than assumptions.

Symptom severity does not directly measure malignant potential.

Slide 28 · Pediatric presentations may extend beyond dysphonia

Young children may show chronic cough or noisy breathing.

Airway narrowing can present with inspiratory stridor or breathing difficulty.

The clinical picture can resemble common respiratory disorders.

Anatomic evaluation is decisive when symptoms are persistent or progressive.

Slide 29 · Hemoptysis: A mechanically plausible consequence

Papillomas on the free edge of the cord experience repeated trauma.

Ulcerated, vascular surfaces may bleed.

Hemoptysis merits evaluation; It is not a specific marker of carcinoma.

Slide 30 · Clinical presentation depends on three variables

Site

Vocal edge versus other airway mucosa

Burden

Single small lesion versus multifocal growth

Course

Stable appearance versus repeated recurrence

Slide 31 · Laryngoscopy supplies the anatomic diagnosis

Symptoms and examination

Hoarseness, stridor or other concern

Endoscopic visualization

Inspect site, multiplicity, and airway size

Biopsy when indicated

Confirm squamous papilloma and assess atypia

Slide 32 · Macroscopic recognition at laryngoscopy

Papillomatous lesions may appear soft, pink, and lobulated.

Surface projections give a finely papillary or wart-like appearance.

Record whether the lesion is solitary or clustered.

Location relative to the free vocal-fold edge helps explain symptoms.

Slide 33 · Tissue diagnosis: How to examine the specimen

Confirm papillary architecture

Fibrovascular cores

Examine epithelial maturation

Orderly squamous lining

Search for atypia and invasion

Report genuine concern rather than recurrence alone

Slide 34 · Histologic diagnosis does not require routine HPV typing

In characteristic lesions, morphology and clinical context establish the diagnosis.

HPV 6/11 is already strongly associated with recurrent papillomatosis.

HPV ISH or PCR may be informative in selected or research contexts.

No routine viral assay should substitute for assessing invasion.

Slide 35 · P16 is not a stand-alone discriminator

P16 overexpression is associated with some high-risk HPV-driven tumors.

That framework should not be mechanically applied to HPV 6/11 laryngeal papillomas.

A negative p16 result does not exclude a low-risk HPV papilloma.

Slide 36 · A focused pathology report

Diagnosis

Squamous papilloma / papillomatous lesion

Morphology

Papillary fronds with fibrovascular cores

Atypia

Describe dysplasia if truly present

Sampling

State limitations when invasion cannot be assessed

Slide 37 · Differential: Reactive vocal-fold nodule or polyp

Feature

Reactive nodule / polyp

Squamous papilloma

Surface

Typically smooth / rounded

Papillary / lobulated

Etiology

Voice strain or smoking context

HPV 6/11 association

Stroma

Loose, myxoid, fibrotic, or vascular

Discrete fibrovascular papillary cores

Histology

Reactive squamous cover over altered stroma

Squamous-lined finger-like fronds

Slide 38 · Reactive polyps: Why the stroma differs

Vocal-fold polyps are reactive lesions rather than HPV-driven neoplasms.

The stromal component may be edematous, myxoid, fibrotic, or vascular.

Architecture is generally smooth or polypoid, not slender papillary fronds.

Slide 39 · Nodules versus polyps: Pattern recognition

Feature

Vocal-fold nodule

Vocal-fold polyp

Typical laterality

Bilateral

Unilateral

Common setting

Repeated voice strain

Voice strain / smoking

Microscopic basis

Reactive squamous cover and altered stroma

Similar reactive stromal changes

Key distinction

Not HPV papillomatosis

Not HPV papillomatosis

Slide 40 · Papilloma versus dysplastic squamous mucosa

Feature

Papilloma

Dysplasia

Defining pattern

Exophytic fibrovascular fronds

Epithelial cytologic/architectural atypia

Cell maturation

Usually orderly

Progressively disturbed with grade

Invasion

Absent in benign papilloma

Absent in pure dysplasia

Clinical implications

Can recur

Premalignant risk depends on grade

Slide 41 · Papilloma versus exophytic carcinoma

Diagnostic question

Papilloma favors

Carcinoma concern

Epithelial cytology

Orderly squamous cells

Significant malignant cytologic atypia

Tissue interface

No destructive invasion

Infiltrative epithelial nests / tongues

Gross appearance

Delicate, soft papillary lesion

May be irregular, ulcerated, or fungating

Decisive step

Inspect histology

Assess deep interface and invasion

Slide 42 · The key cancer pitfall: Reactive atypia

Inflammation, repeated trauma, and repair can distort benign epithelial cytology.

Interpret mitoses and nuclear changes relative to epithelial layer and injury.

Unequivocal dysplasia should be described; Do not infer it from HPV positivity.

Concern for infiltration requires an adequately sampled epithelial–stromal interface.

Slide 43 · Features prompting expanded assessment

Clinical change

Unexpected rapid change, ulceration or persistent worsening

Microscopy

Significant epithelial atypia or possible destructive growth

Risk context

Smoking or prior irradiation in a recurrent lesion

Next action

Correlate, re-examine deeper tissue, or resample as indicated

Slide 44 · Risk of malignant transformation is low, not zero

Squamous carcinoma arising from papillomas as rare.

Tobacco exposure and prior irradiation are contexts of concern.

Neoplastic risk must be distinguished from the much more common risk of recurrence.

Slide 45 · Recurrent papillomatosis is frequently a longitudinal disease

Local removal

Remove visible disease

Clinical improvement

Voice/airway can improve

Possible regrowth

Repeat evaluation and procedures may be needed

Slide 46 · Clinical treatment goals

Airway

Maintain adequate patency

Voice

Preserve vocal-fold function

Disease control

Reduce symptomatic burden

Tissue preservation

Limit injury from repeated intervention

Slide 47 · Endoscopic resection is a primary approach

Endoscopic removal as usual therapy.

Endoscopic access permits site-directed treatment of visible papilloma.

Surgery removes lesions but cannot guarantee permanent eradication of disease.

Slide 48 · Tissue-sparing surgery matters in the larynx

Surgical precision must balance lesion removal against damage to healthy vibratory mucosa.

Repeated intervention can lead to fibrosis or impaired voice.

Airway safety takes priority when obstruction develops.

Operative technique is selected by the treating airway specialist.

Slide 49 · Why recurrent lesions often need repeated procedures

Viral-associated disease persists

Underlying susceptibility / infection

Visible papilloma removed

Anatomic burden decreases

Disease may reappear

Follow-up remains necessary

Slide 50 · Follow-up assesses function as well as recurrence

Voice

Hoarseness or voice fatigue

Breathing

Stridor, dyspnea, airway symptoms

Anatomy

Endoscopic recurrence or extension

Histology

Resample when new suspicious features emerge

Slide 51 · Adjuvant therapies: Separate disease control from cure

Advanced or repeatedly recurrent RRP may require measures beyond local surgery.

Bevacizumab and other adjuvant approaches have been evaluated in selected patients.

The evidence and indications differ across treatments and populations.

This lecture does not treat such approaches as an established universal cure.

Slide 52 · HPV vaccination targets the causal viral types

Vaccine prevention

Vaccines containing HPV 6/11 antigens

Fewer vaccine-type HPV infections

Prevention of vaccine-type infection

Reduced juvenile RRP burden

Population-level decline observed after vaccine introduction

Slide 53 · Vaccination evidence: Separate prevention from treatment

Question

What evidence supports

What not to infer

Prevention

CDC documents decline in juvenile-onset RRP

Not a guaranteed individual preventive outcome

Established papilloma

Vaccination is not equivalent to surgical removal

No claim of certain cure

Clinical recurrence

Adjunctive vaccine studies exist

Cannot generalize all study findings

Slide 54 · The HPV 6/11 link explains prevention logic

The same HPV types repeatedly underlie benign laryngeal papillomatosis.

A vaccine targeting these types interrupts the causal infection pathway.

CDC reports significant declines in juvenile-onset disease following vaccine introduction.

Slide 55 · Clinical reasoning case: Persistent adult hoarseness

A 29-year-old has progressive hoarseness. Laryngoscopy shows a small, soft exophytic lesion on the true vocal fold.

What architecture should you expect on biopsy?

What viral types are most relevant?

Interpretation: Finger-like squamous-lined papillae with fibrovascular cores; HPV 6 and 11.

Slide 56 · Clinical reasoning case: Child with recurrent stridor

A school-aged child develops hoarseness and recurrent noisy breathing. Endoscopy identifies multiple laryngeal papillary lesions.

What is the likely clinicopathologic syndrome?

What makes this condition important despite benign histology?

Interpretation: Recurrent respiratory papillomatosis; Repeated recurrence and airway compromise.

Slide 57 · Microscopy reasoning exercise

Biopsy shows multiple slender exophytic epithelial fronds, mature squamous lining, vascular cores, and no infiltrative growth.

What is the best morphologic diagnosis?

Which single missing finding would most change the malignant assessment?

Interpretation: Squamous papilloma; Unequivocal destructive stromal invasion (with malignant cytology) would trigger concern.

Slide 58 · A structured diagnostic pathway

Laryngeal exophytic lesion

Papillary fronds + fibrovascular cores?

Maturation preserved and no invasion?

Squamous papilloma

If not: Assess reactive polyp, dysplasia, or other tumor

If not: Evaluate atypia, sampling, and carcinoma

Slide 59 · High-yield distinctions

Finding

Interpretation

Exophytic fibrovascular squamous fronds

Supports squamous papilloma

HPV 6/11 and recurrent multiplicity

Supports respiratory papillomatosis

Rounded smooth vocal-fold lesion with myxoid stroma

Favors reactive polyp

Destructive epithelial stromal infiltration

Requires assessment for invasive SCC

Recurrent benign papilloma

Not automatically malignant

Slide 60 · Five concepts to retain

Laryngeal squamous papilloma is a benign, exophytic HPV 6/11–associated lesion.

Its histologic signature is finger-like fronds with fibrovascular cores.

Orderly squamous maturation and absent invasion support benign diagnosis.

Multiplicity and recurrence create substantial voice and airway morbidity.

Endoscopic control and HPV vaccination address different points in disease prevention and care.

Slide 61 · Selected references

Robbins, Cotran & Kumar. Pathologic Basis of Disease. 11th ed. 2026; Ch 16, p 676.

NIDCD. Recurrent Respiratory Papillomatosis. NIH informational resource (2017).

Bentley PL, et al. Head Neck Pathol. 2019;13:235–238. doi:10.1007/s12105-018-0912-8.

Kumar N, Preciado D. Front Pediatr. 2019;7:383. doi:10.3389/fped.2019.00383.

CDC. HPV Vaccine Safety and Effectiveness Data. Updated July 9, 2024.