Squamous Papilloma: Causes, Symptoms, Diagnosis, and Treatment

Squamous papilloma is a benign epithelial tumor that commonly affects the oral cavity, larynx, and skin. It is typically caused by Human Papillomavirus (HPV), particularly types 6 and 11, and appears as a small, painless, wart-like growth. While squamous papilloma is non-cancerous, proper diagnosis and treatment are essential to prevent complications or recurrence.

In this article, we will explore the causes, symptoms, diagnosis, and treatment of squamous papilloma, along with preventive measures and frequently asked questions to help you better understand this condition.

What is Squamous Papilloma?

Squamous papilloma is a benign (non-cancerous) epithelial growth that commonly appears in the oral cavity, larynx, or skin. It is characterized by small, wart-like lesions with a papillary or cauliflower-like appearance. These growths are generally painless and slow-growing but may become irritated depending on their location, especially in the mouth or throat.

How Does Squamous Papilloma Form?

The primary cause of squamous papilloma is infection with the Human Papillomavirus (HPV), particularly types 6 and 11. These low-risk HPV strains trigger abnormal but non-malignant cell proliferation in the epithelium. The virus is typically transmitted through:

• Direct contact with infected surfaces (e.g., kissing or oral-genital contact)
• Self-inoculation (e.g., touching an existing wart and then the mouth)
• Vertical transmission (from mother to child during childbirth in cases of laryngeal papillomatosis)

Since HPV can remain dormant in the body, squamous papillomas may develop months or even years after exposure.

Squamous Papilloma vs. Verruca Vulgaris (Common Wart)

Although squamous papilloma and verruca vulgaris (common warts) may appear similar, there are key differences:

While both conditions result from HPV infection, squamous papillomas are more commonly found in mucosal tissues, whereas verruca vulgaris affects keratinized skin.

Squamous papilloma is benign, but proper diagnosis is necessary to rule out other similar lesions that may be precancerous or malignant.

Causes and Risk Factors of Squamous Papilloma

Causes of Squamous Papilloma

The primary cause of squamous papilloma is infection with the Human Papillomavirus (HPV), specifically HPV types 6 and 11. These are classified as low-risk HPV strains, meaning they do not typically lead to cancer. When the virus infects the epithelial cells, it causes abnormal but benign cell proliferation, leading to the formation of a small, wart-like growth.

Risk Factors for Squamous Papilloma

While anyone exposed to HPV can develop squamous papilloma, certain factors increase the risk, including:

1. HPV Exposure – Individuals who have frequent close contact with HPV-infected persons are at higher risk.
2. Weakened Immune System – People with immunosuppression (e.g., HIV/AIDS, chemotherapy patients, organ transplant recipients) have a higher likelihood of developing squamous papillomas.
3. Poor Oral Hygiene – Lack of oral care can create an environment where HPV thrives, increasing the risk of oral squamous papillomas.
4. Smoking and Alcohol Consumption – Both habits can weaken the oral mucosal barrier, making it easier for HPV to infect epithelial cells.
5. Frequent Skin or Mucosal Trauma – Constant irritation (e.g., ill-fitting dentures, biting the cheeks or tongue) may contribute to papilloma formation.
6. Age Factor – Squamous papillomas are more commonly seen in adults aged 30-50, but can also occur in children (especially in cases of laryngeal papillomatosis).
7. Unprotected Oral Sex – HPV transmission through oral-genital contact increases the risk of oral squamous papillomas.

Since HPV-related papillomas are non-cancerous, they do not pose a serious health threat in most cases. However, early detection and treatment help prevent growth, discomfort, and potential complications.

Symptoms and Clinical Presentation of Squamous Papilloma

Squamous papillomas are benign, slow-growing lesions that often go unnoticed unless they cause discomfort or are located in a visible area. Their clinical presentation varies depending on the size, location, and level of irritation they experience.

Common Locations

Squamous papillomas can develop on any mucosal surface but are most commonly found in:

• Oral cavity: Tongue, soft palate, lips, buccal mucosa, uvula, gingiva
• Larynx: Vocal cords (laryngeal papillomatosis)
• Esophagus: Rare but can cause swallowing difficulties
• Skin: Less common but may appear in keratinized areas

Physical Characteristics

• Small, wart-like lesion (typically 0.2 – 1 cm in size)
• Soft, exophytic (growing outward) mass
• Pedunculated (attached by a stalk) or sessile (flat-based)
• White, pink, or slightly red color (depending on keratinization and location)
• Papillary or cauliflower-like texture

Symptoms Based on Location

1. Oral Squamous Papilloma
   • Painless lesion unless irritated by biting or brushing
   • Rough, finger-like projections
   • No ulceration or bleeding unless traumatized
2. Laryngeal Squamous Papilloma
   • Hoarseness or voice changes
   • Difficulty breathing (in severe cases)
   • Chronic cough
3. Esophageal Squamous Papilloma
   • Dysphagia (difficulty swallowing)
   • Sensation of a lump in the throat
   • Occasional pain when swallowing

When to Seek Medical Attention

Although squamous papillomas are benign, medical evaluation is recommended if:

• The lesion grows rapidly
• There is persistent irritation or pain
• It bleeds without trauma
• Multiple lesions appear (could indicate immune suppression or extensive HPV infection)

Early diagnosis and treatment can help prevent discomfort, infection, or confusion with malignant lesions.

Diagnosis of Squamous Papilloma

Diagnosing squamous papilloma involves a combination of clinical examination, histopathological analysis, and sometimes HPV testing to differentiate it from other similar lesions, including verruca vulgaris, condyloma acuminatum, and squamous cell carcinoma.

1. Clinical Examination

A healthcare professional, such as a dentist, ENT specialist, or dermatologist, will assess the lesion based on:

• Location and appearance (exophytic, papillary, cauliflower-like)
• Size and texture (soft, pedunculated, or sessile)
• Color (white, pink, or red depending on keratinization)
• Symptoms (painless unless irritated or traumatized)

In oral or laryngeal cases, laryngoscopy or endoscopy may be performed to visualize lesions in deeper areas like the vocal cords or esophagus.

2. Histopathological Examination (Biopsy)

A biopsy is the gold standard for confirming squamous papilloma. This involves:

• Excisional biopsy (complete removal for small lesions)
• Incisional biopsy (partial sample for larger lesions)

Histological Features

• Papillary projections with a fibrovascular core
• Hyperkeratosis (thickened keratin layer, especially in oral lesions)
• Presence of koilocytes (enlarged epithelial cells with perinuclear halos, indicating HPV infection)
• No dysplasia or malignancy (helps differentiate from squamous cell carcinoma)

3. HPV Testing (Optional)

Although not always necessary, HPV DNA testing may be used to confirm infection, particularly in cases of:

• Multiple or recurrent papillomas
• Laryngeal papillomatosis
• Uncertain diagnosis

Techniques like polymerase chain reaction (PCR) or in situ hybridization can detect HPV types and confirm viral involvement.

Differential Diagnosis

Since squamous papilloma resembles other lesions, a proper diagnosis helps rule out:

Treatment Options for Squamous Papilloma

Squamous papillomas are benign and generally do not require treatment unless they cause discomfort, interfere with function (e.g., swallowing or speaking), or show signs of growth or irritation. However, in most cases, removal is recommended to prevent recurrence and ensure accurate diagnosis.

1. Surgical Removal (First-Line Treatment)

The most effective treatment for squamous papilloma is surgical excision, which ensures complete removal and minimizes recurrence.

✅ Excision Techniques:

• Scalpel Excision – The lesion is surgically removed with minimal damage to surrounding tissue.
• Electrosurgery (Electrocautery) – Uses electric current to cut and coagulate tissue, reducing bleeding.
• Laser Ablation (CO₂ or Nd:YAG laser) – A precise, minimally invasive technique often used for laryngeal or oral papillomas.
• Cryotherapy – Freezing the lesion with liquid nitrogen, commonly used for skin papillomas.

⚠️ Important Considerations:

• Complete removal is crucial to prevent recurrence.
• Excisional biopsy is performed to confirm benign histology.
• Surgical removal is usually painless with local anesthesia.

2. Non-Surgical Treatments

For small or multiple lesions, non-surgical treatments may be considered:

• Topical Agents(Used mainly for skin papillomas, less common for oral cases)
  • Trichloroacetic acid (TCA) – Chemically burns off the lesion.
  • Imiquimod (Aldara) – Stimulates the immune system to clear HPV-infected cells.
• Photodynamic Therapy (PDT)
  • Uses light-sensitive compounds and laser exposure to target HPV-infected cells.
  • Effective for oral and laryngeal papillomas, though less commonly used.

3. HPV Management and Prevention

Since squamous papilloma is caused by HPV infection, preventing viral spread can reduce recurrence.

✅ Preventive Strategies:

• HPV Vaccination (Gardasil 9, Cervarix) – Protects against high-risk and low-risk HPV types, including HPV 6 and 11.
• Good Oral Hygiene – Reduces irritation and risk of oral lesions.
• Avoiding Direct Contact – Prevents transmission (e.g., safe sexual practices, not touching existing lesions).

When to Seek Treatment?

• If the lesion grows, bleeds, or becomes painful
• If it causes speech or swallowing difficulties (laryngeal/esophageal cases)
• If there is recurrence after prior removal

Can Squamous Papilloma Become Cancerous?

Squamous papilloma is a benign (non-cancerous) lesion caused by low-risk HPV types 6 and 11. These HPV strains are not associated with malignant transformation, meaning squamous papillomas do not typically turn into cancer. However, certain factors may raise concerns and warrant medical attention.

1. Low Malignant Potential

• Unlike high-risk HPV types (HPV 16, 18), which are linked to cancers such as oropharyngeal and cervical cancer, HPV 6 and 11 rarely lead to malignancy.
• Squamous papillomas generally grow slowly and do not invade deeper tissues.
• Malignant transformation is extremely rare and usually occurs in individuals with chronic HPV infections or immunosuppression.

2. When to Be Concerned?

Although squamous papillomas are benign, medical evaluation is needed if the lesion:
✅ Grows rapidly or increases in size unexpectedly
✅ Develops ulceration, bleeding, or pain
✅ Persists despite treatment or frequently recurs
✅ Appears in immunocompromised individuals (e.g., HIV/AIDS, organ transplant recipients)

In these cases, a biopsy is necessary to rule out squamous cell carcinoma (SCC), especially if the lesion has atypical features.

3. Differentiating from Cancerous Lesions

Squamous papilloma may resemble oral squamous cell carcinoma (OSCC) or verrucous carcinoma, but key differences include:

4. HPV and Cancer Risk

While squamous papilloma itself does not become cancerous, persistent HPV infections with high-risk strains (HPV 16, 18) can increase the risk of cancer in other areas, such as:

• Oropharyngeal cancer (back of the throat, tonsils, base of the tongue)
• Cervical, anal, and genital cancers

This highlights the importance of HPV vaccination (e.g., Gardasil 9) for long-term prevention.

Frequently Asked Questions (FAQs) About Squamous Papilloma

1. Is squamous papilloma contagious?

Yes, squamous papilloma is caused by HPV (human papillomavirus), specifically low-risk types 6 and 11, which can spread through direct contact with infected mucosa or skin. However, it is not highly contagious like other HPV-related conditions such as genital warts.

2. Can squamous papilloma go away on its own?

In rare cases, small papillomas may regress on their own, especially in individuals with a strong immune system. However, most lesions persist and require removal if they cause discomfort or interfere with function.

3. What happens if squamous papilloma is left untreated?

Untreated squamous papillomas usually remain benign and do not cause serious complications. However, they may:

• Grow larger over time
• Cause irritation or discomfort (especially in the mouth or throat)
• Lead to voice changes (if located on the vocal cords)
• Be confused with malignant lesions, requiring biopsy for confirmation

4. Does squamous papilloma always need to be removed?

Not always. If the lesion is small, painless, and not growing, a doctor may recommend monitoring instead of immediate removal. However, surgical excision is often advised to:

• Prevent recurrence
• Rule out malignant changes
• Eliminate cosmetic or functional concerns

5. How can I prevent squamous papilloma?

To reduce the risk of developing squamous papilloma:
✅ Get vaccinated against HPV (Gardasil 9 protects against HPV 6 and 11)
✅ Maintain good oral hygiene to prevent infections
✅ Avoid direct contact with infected lesions
✅ Strengthen your immune system (healthy diet, no smoking, regular exercise)

6. Can squamous papilloma come back after treatment?

Recurrence is rare but possible, especially if:

• The lesion was not completely removed
• There is persistent HPV infection
• The immune system is weakened

7. What is the difference between squamous papilloma and verruca vulgaris?

8. Can squamous papilloma become cancerous?

No, squamous papilloma is benign and does not turn into cancer. However, a biopsy is necessary if a lesion shows suspicious signs such as rapid growth, ulceration, or bleeding, to rule out squamous cell carcinoma (SCC).

9. Can children get squamous papilloma?

Yes, children can develop oral or laryngeal squamous papillomas, often due to maternal transmission of HPV during birth. This condition, called juvenile-onset recurrent respiratory papillomatosis (JORRP), affects the voice and airway and may require repeated treatments.

10. How long does it take to recover after surgical removal?

• Oral or skin papilloma: Healing takes about 1–2 weeks.
• Laryngeal or esophageal papilloma: Recovery may take longer, especially if multiple lesions are removed.
• Post-surgery care: Avoid spicy foods, smoking, and alcohol to prevent irritation.

Conclusion

Squamous papilloma is a benign growth caused by low-risk HPV types, typically HPV 6 and 11, and while it can be bothersome, it is rarely associated with cancer. Early diagnosis, usually through clinical examination and biopsy, is important to differentiate it from other lesions. Treatment options, primarily involving surgical removal, are effective in preventing recurrence and ensuring comfort. While squamous papilloma does not generally turn cancerous, preventive measures such as HPV vaccination and maintaining good hygiene can help reduce the risk of future lesions. If you notice any unusual changes or discomfort, be sure to consult with a healthcare provider for guidance.