Benign tumors of the oral mucosa.

Benign tumors of the oral mucosa.

1. Introduction 

Benign tumors of the oral cavity represent all histologically benign or relatively benign neoformations developing from the constituent elements of the oral mucosa.    

These lesions are clinically distributed according to their macroscopic appearance, but their diagnosis remains histological and their classification depends on the nature of the tissues that compose them.

Their frequency is high but remains difficult to assess; nearly a third of the population would be affected. 

Definition of tumor lesion.

• It is necessary to differentiate between tumor and swelling = “lump”. 
•  Neoformation = neoplasia = neoplasm

• DEFINITION OF TUMOR : abnormal tissue lesion resulting from excess   cellular proliferation  leading to the development of  new tissue  = neoformation whose  disordered growth  exceeds that of normal tissues.
• This lesion persists after the cessation of the stimuli which gave rise to it, thus acquiring a certain  autonomy  with respect to the organism (therefore no longer obeys the laws of homeostasis)

NEOPLASIA (additional features) 

• unnecessary abnormal mass

• its growth competes with normal cells and tissues for their supply:
– of energy
– of nutritional substrates.

1. Pseudo-tumor states  = swellings

They are very numerous and are divided into 4 groups: 
– Inflammation
– Hyperplasia
– Dysplasia
– Dystrophy.

• Hyperplasia.

 Definition: It is the  exaggerated development of a tissue or an organ.

According to WHO: Hyperplasia is the increase in the number of cell layers. 

Opposition with neoplasia.

   Hyperplasia is hyperproliferation but it does not result in new tissue.
When the stimulus stops, the hyperplasia stops.
Not all hyperplasia is pathological.

• Dysplasia.

Definition: failure of a tissue or organ to develop.

 At the cellular level: These are precancerous lesions.

 At the tissue level: These are tissue lesions secondary to a malformation occurring during embryonic development.

• Dystrophy.

 Definition: It is a tissue lesion acquired after birth and secondary to various disorders affecting cellular life.

• Hypertrophy = increase in cell volume (WHO).

2. Characteristics of the benign tumor process 

– Slow evolution

– The tumor is well limited.

– Respecting or pushing back neighboring elements.

– No deterioration in general condition.

– The cellular elements of the tumor tissue are morphologically and functionally reminiscent of the original cell; there is no cytonuclear abnormality.

– Never gives metastasis.

– Good progress after treatment with a generally good prognosis. 

Benign tumors of the oral mucosa can be classified according to their histological nature into:

• Pseudotumors; 
• Epithelial tumors; 
• Connective tissue tumors. 

Benign tumors of the oral mucosa.

3. Pseudotumors of the oral mucosa

3.1. Epulis

It is a benign hyperplastic pseudotumor of the gum. The term epulis comes from the Greek “epi”: on and “oulon”: gum, and which corresponds to any tissue formation located on the gingival surface.

1. Etiopathogenesis

These pseudotumors are thought to be inflammatory reactions responding to an irritative phenomenon. Indeed, these lesions are often located in the vicinity of an irritating dental or prosthetic spine in the presence of poor oral hygiene. However, the pathogenesis of epulis is not completely elucidated, the main etiology being a local cause.

2.  Diagnosis

The diagnosis of epulis is often obvious by clinical inspection alone, but histopathological examination is essential to support the diagnosis. A general interview about the patient’s condition and history of the disease is also essential.

3. Clinical aspect: 

• Observed at any age, with female predominance 
• Variable size
• Can be plain, bi or polylobed
• Its covering surface can be smooth or budding; pink, bright red or purplish in color, it can also be ulcerated. 
• The lesion is soft or elastic in consistency  
• Often pedunculated, but sometimes sessile
• Sometimes presents a spontaneous hemorrhagic tendency or after slight irritation. 

4.  Radiology: 

If the implantation base is bony, alveolysis is observed in the affected region.

5.  Histological appearance: 

• Inflammatory epulis: presence of a dense polymorphic inflammatory infiltrate. 
• Fibrous epulis: predominance of fibroblasts. 
• Vascular epulis: there is an abundance of new vessels in the tumor.   
• Giant cell epulis or myeloplaxous epulis: often presents nodular aspects with the presence of multinucleated giant cells characteristic of this lesion, these giant cells are also called myeloplaxous. 

Some special epulis: 

• Congenital epulis of the newborn: Neumann tumor.
• Epulis gravidarum: or pregnancy granuloma: It appears as a small, fleshy, bright red, pedunculated and bleeding mass easily observed in a pregnant woman.

3.1.6. Treatment of epulis: 

* Elimination of local irritation factors (tartar, caries, roots, etc.)

* Excision under local anesthesia of the entire lesion, including its bony anchor point.

* Curettage of the osteolysis area, if it exists, or even the avulsion of a tooth with periapical alveolysis (to minimize the risk of recurrence). 

* Anatomopathological examination of the surgical specimen. 

2.  Fissural epulis (prosthetic fibrous hyperplasia or book leaf hyperplasia)  :
   1. Clinic:

• It is the consequence of a poorly adapted prosthesis and has a pseudo-tumor clinical appearance. 
• It appears as a mucous ridge, covered with normal mucosa sometimes ulcerated by the prosthesis. 
• Its consistency is firm. This formation is often developed at the bottom of the vestibule, doubling the alveolar crest, it arises from the free mucosa, which completely separates it from epulid lesions whose localization is gingival. 

2. Histology: 

Abundance of collagen fibers and cellular poverty. 

In some cases, calcification or even ossification of the tumor is observed, especially hyperplasia near the bone.

Benign tumors of the oral mucosa.

3. Treatment : 

• Treatment is surgical by excision of the hyperplasia and correction of the prosthesis to prevent recurrence.

3.3. Botryomycoma:

Also called fleshy bud, pyogenic granuloma, telangiectatic granuloma, (telangiectasia being the tortuous dilation of a capillary).

• It is a hyperplastic pseudotumor corresponding to an exaggerated inflammatory response to trauma, it would be associated with a microbial factor (botryomyces).
• Botryomycoma is most often painless.

 3.3.1. Clinic:

• Implanted at any point on the oral mucosa, this bud can reach 3 cm in diameter. 
• It is more or less bright red in color.
• Often ulcerated, superinfected, it is then covered with purulent exudates. 
• Firm in consistency, elastic, quite resistant, it bleeds at the slightest contact. 
• The most constant characteristic of botromycoma is pediculization. 

3.3.2. Histology:

• large necrotic ulceration lined with fibrin-leukocyte exudates and 
• The underlying connective tissue harbors numerous capillaries surrounded by polymorphic inflammatory cells.

3.3.3. Treatment: excision of the lesion at its base, or curettage when the lesion is in the alveolus. 

3.4. Eruption cyst:

It is a cystic formation located opposite a tooth in the process of erupting. It is a bluish, translucent, repressible mass, of firm consistency, sometimes fluctuating, raised in a dome on the arch above an erupting tooth.

 A simple incision of the mucosa without traumatizing the tooth germ allows healing to occur.

3.5. Diapneusia: (suction nodule) 

3.5.1. Clinic: 

These lesions are mainly located on the inner side of the cheek, on the lower lip, or near the corner of the lip and the tongue, most often opposite a hiatus.

“Due to a gap between two teeth or a missing tooth, the patient sucks his mucosa through this gaping area, and little by little a diapneusic nodule forms.” 

It is a well-defined nodule of firm consistency forming a projection of the same color as the mucous membrane.

3.5.2. Histology: 

The diapneusic nodule is covered with a normal epithelium. Its fibrous connective axis traps a few muscle fibers disorganized by the chronic attraction which caused the lesion.

3.5.3. Treatment:

Treatment of diapneusia is surgical by excision of the lesion and correction of irritating factors.

4. Epithelial tumors:
   1. Papilloma: 

It is a benign neoplasia of viral origin due to the Human Papilloma virus (HPV)

1. Clinic: 

Papilloma presents as

• a well-circumscribed, pedunculated or sessile, prominent neoformation,
•  single or multiple, 
• the numerous outgrowths (epithelial digitations) give the tumor surface a cauliflower appearance,
•  the coloring is white or grayish.
• The most common site is the vestibular and palatine mucosa and on the dorsal surface of the tongue. 

2. Histology:

• The squamous epithelium is thickened, its swollen ridges invaginate deeply into the chorion. On the surface it is often keratinized.

3. The diagnosis of this lesion is most often easy; however, the large volume of this neoformation sometimes makes the diagnosis with verrucous carcinoma difficult.
4. Treatment: surgical excision. 
5. Oral Papillomatosis Florida POF (Verrucous Hyperplasia)  : 

It is an almost obligatory precancerous lesion because if the observation time is long enough, the occurrence of an invasive carcinoma is constant.

It is more likely to affect certain sites: cheek, gums and alveolar ridges, palate, floor of the mouth.

1. Clinical: 

POF can resemble a benign papilloma, and presents as a tumor that is more or less prominent on the mucosal surface, made up of tufts of fine, more or less elongated villi, white or pink in color with a tendency to spread superficially, progressively, very slowly, forming one or more well-defined patches, more or less raised. 

These lesions are sometimes a little rough but always flexible.

Consultation is often late due to the lack of functional signs.

2. Histology:

At the beginning the lesion is therefore exclusively intra-epithelial then cyto-nuclear anomalies and a breach of the basement membrane with infiltration of the connective tissue can occur (for verrucous carcinoma).

The transformation is almost always preceded by the appearance of severe dysplasia.

Oral Papillomatosis Florida or POF is classified into 3 grades:

POF grade 1: benign lesion

POF grade 2: presence of dysplasia

POF grade 3: carcinoma.

3. Evolution :

Benignity is durable but malignant transformation is the rule.

4. Treatment : 

• Surgical excision. 
• Monitoring.
• Sometimes chemotherapy. 

3.   Warts (common warts)

• It is a benign skin condition caused by a specific human papilloma virus (HPV 2 and 4) occurring most often in children by autoinoculation from skin lesions.

1. clinic: 

These warts can be located anywhere on the oral mucosa, but the lips and tongue are most commonly affected.

They have the appearance of a well-defined exophytic tumor, small, whitish or normal in color, with a cauliflower appearance, they can be single or multiple

2. Histology:

The epithelium is thickened and forms a mass made up of lobules, the cells are the site of keratosis and separate from each other.

3. Treatment : 

Surgical excision, electrocoagulation, cryotherapy.

4. Condylomata acuminata, venereal warts, venereal condyloma (WHO 2005): 

4.4.1. Clinic:

– Sexually transmitted infection; 

– Possibility of direct orogenital contamination and autoinoculation. 

– Oral condylomata acuminata are the analogues of ano-genital condylomata acuminata.

– Are often due to HPV 6 and 11.

– Frequent between the 2nd ^and 5th ^decades , with a peak in adolescents and young adults.

– When found in children, they should suggest sexual abuse.

– Location: the entire oral mucosa; especially the lips, tongue and palate.

4.4.2. Histopathology:

The cytopathogenic effect is characterized by koilocytosis*: this is a cell, described in 1956 by Koss, of the intermediate or outermost layers with an edematous nucleus, irregular chromatin (indicating viral activity) and above all the existence of a perinuclear intracytoplasmic vacuole pushing the cytoplasm to the periphery; this vacuole appears optically empty. 

At the tissue level, epithelial proliferation and architectural modification with the appearance of micro papillae are noted.

Benign tumors of the oral mucosa.

5. Heck’s disease or focal epithelial hyperplasia:
6. Clinic:

• First described ^by Archard and Heck in 1965.
• Due to HPV. In 90% of cases it is due to HPV 13 or 32. 

In children of Eskimos and American Indians, patients from North Africa and the West Indies. Identical lesions are also observed in the HIV-positive population in which HPV32 predominates.

• Exophytic papules or nodules. 
• Painless, exceptionally painful. 
• Location: oral mucosa, gums, tongue and lips.

4.6. Melanocytic tumors:

– Within the chorion, both at the cutaneous and mucous level, we find cells secreting melanin: melanocytes. Melanin is a brown, granular pigment derived from tyrosine. It is present mainly in the skin, to which it gives its color. Its excess production can be physiological or pathological. 

Some benign tumors found in the oral cavity may originate from a proliferation of these melanocytes: these are called nevi. There are different types, some of which are linked to systemic syndromes.

The most common nevus in the oral cavity is the intramucosal nevus followed by the blue nevus.

Any pigmented spot on the oral mucosa is considered to be a malignant melanoma until proven otherwise. 

– It must always be kept in mind that we never biopsy a malignant melanoma but perform a complete excision. 

• The blue mole:

• 1st oral case described by Scofield in 1959 (at the level of the palate) ^.
• Usually in the form of a papule
• Characterized by a high concentration of dendritic melanocytes, melanophages and a high degree of fibrosis. 
• Approximately 33% of oral moles are blue moles.  
• Variable color: gray, brown, slate blue, midnight blue. 
• Rarely exceeds 6 mm
• Ota’s nevus: 

• First described ^by Hulke in 1860
• Defined by Ota in 1939* under the term “  naevusfuscocaeruleus ophtalmo-maxillaris”
• Described in 0.1 to 0.2% of the Japanese population and other Asians, black ethnicity; rare in Caucasians. 
• Slate-gray coloring, diffuse or spotted.
• Affects women 5 times more than men.

The nevus of Ota is located between the 1st ^and 2nd ^branches of the trigeminal nerve and the nevus of Ito is located in the area of ​​the acromioclavicular nerve.

* Unilateral can be bilateral in 5% of cases.

* Affects the territory of V1 and V2 (periorbital region, forehead, malar, cheeks, wing of the nose).

* Mucous membranes: palpebral conjunctiva, sclera, palatine, nasal.

* They are characterized by the presence of dendritic cells derived from melanocytes that have migrated from the neural crests to the epidermis.

* Present at birth or appears during the first ^year of life in half of the cases and during adolescence for the others.

* Pigmented macules increase in number and spread with age.

* Histologically, there is dispersion of melanocytes from the dermis into the epidermis

* Malignant transformation into melanoma: rare +++ at the choroid level

– Treatment: brief applications of dry ice

* Surgical abrasion

* Laser 

– Differential diagnosis:

• Malignant melanoma
• Metastasis of malignant melanoma
• Iatrogenic tattooing by amalgam
• Malignant blue mole
• Kaposi’s sarcoma
• Hemangioma 
• Post inflammatory pigmentation
• Pigmented lichen and lichen nigricans
• Addison’s disease
• Coloring during HIV… 

5. Benign Conjunctival Tumors: 
6. Fibroid  : 

These are benign tumors that are difficult to differentiate from simple fibroepithelial hyperplasias; they originate from connective tissue. 

a .Clinic:

 It is a nodular lesion of variable size but well limited, firm, sessile or pedunculated, covered with a smooth epithelium, normal in appearance or sometimes whitish in color. 

a. Histology:

 The lesion is formed of bundles of collagen fibers mixed with fibroblasts without cyto-nuclear abnormalities or mitosis.

b. Treatment:

Surgical excision. 

2. Lipoma:

It is a tumor of fatty tissue, common on the skin and less on the oral mucosa.

1. Clinic: It is a painless, well-defined, pedunculated or sessile tumor, yellowish or pink in color. 

• This is a fairly rare tumor of fatty tissue in the oral cavity,
• Usually located on the jugal mucosa, tongue, vestibulojugal fold, floor of the mouth, lips and gums. 
• Clinically, the mass is soft in consistency, sometimes giving the impression of fluctuation, mobile in relation to the neighboring tissues. It hardens at the bottom and its characteristic yellowish coloring is clearly visible under the epithelium that covers it.
• These tumors are generally composed of mature adipocytes*, surrounded by a thin fibrous capsule.

2. Histology:

The lesion is made up of sheets of perfectly well differentiated fatty tissue.

Histologically, intraoral lipomas are divided into six subtypes:  

• simple lipomas, 
• fibrolipomas, 
• angiolipomas,
• spindle cell lipomas, 
• angiomyolipomas and 
• hibernomas (developed at the expense of brown fat: immature pre-adipocytes 🡪).

In 2001, Nagal et al. described a new entity “sialolipomas”: a lesion combining glandular tissue and adipose components.

3. The differential diagnosis of lipomas is made with liposarcoma where sometimes, the use of immunohistochemistry is imperative because the distinction can be difficult.

• The diagnostic discussion is also made with glandular tumors and pseudotumors, with vascular tumors and nervous tumors. 

4. Treatment : 

Biopsy-excision.

The evolution is benign.

3. Muscle tumors  : = myomas. 

• Among which we distinguish: leiomyomas and rhabdomyomas.

5.3.1. Leiomyomas: TB developed from smooth muscles. 

5.3.2. Rhabdomyomas: TBs developed from striated muscle fibers.

Benign tumors of the oral mucosa.

4. Nerve tumors:
5. Neurofibroma: 

This is a fairly rare TB in the oral cavity which can present as a solitary tumor or multiple lesions in the context of “Von Recklinghausen” neurofibromatosis. 

It presents as a painless, well-defined tumor of nodular shape, pedunculated, firm, covered with normal epithelium. 

2. Schwannoma or Neuroma: derived from Schwann cells of the nerve sheath.
3. Vascular tumors:

Angiomas are benign congenital lesions affecting:

• Blood vessels: hemangioma

Perhaps flat or budding, wine-colored. 

Characterized by the notion of thrill (pulsatile character) and filling. Its rupture causes cataclysmic hemorrhages.

Often associated with skin localizations

• Lymphatic: lymphangioma

No risk of bleeding. It has a transparent, mammary appearance.

6. Soft tissue osteoma:

TB corresponding to mature proliferation of compact or medullary bone.

Location: palatal, jugal, lingual and gingival. 

6. TBMB as a manifestation of systemic disease:
7. Sarcoidosis: 

• Sarcoidosis is a systemic granulomatous disease of undetermined origin,

• Histology: formation of non-caseating tuberculoid granulomas in the affected organs. 
• This condition was formerly known as Besnier-Boeck-Schaumann disease. 
• Often latent, 
• The involvement is mediastinal-pulmonary and can then lead to severe multivisceral localizations. 
• The thorax (mediastinum and lungs) is affected in 80 to 90% of cases. At this level, the lesions mainly affect the lymphatic system (lymph nodes and lungs). 
• Other locations are observed in 30 to 70% of cases in total, with ophthalmic and dermatological involvement being the most frequent.
• Erythema nodosum +++.
• Oral lesions are described. 
• In some cases, they can be indicative of the disease.
•  These tumor-like lesions form nodules located on the gum, the edge of the tongue, and the lips. 
• Gingival hypertrophy may be reported.
• These nodules are generally linked to damage to the accessory salivary glands.
• Negative tuberculin IDR despite BCG vaccine (tuberculin anergy).
• Cured spontaneously except in 20% of cases.
• 20% of cases result in pulmonary fibrosis.

Benign tumors of the oral mucosa.

2. Amyloidosis:

• Amyloidosis , also called  amyloidosis ,  is a large group of diseases. 
• Rare disease, characterized by the presence of  insoluble protein deposits  in tissues . 
• These are deposits of amyloid substance
• Affects all organs and the central nervous system.
• Oral cavity: 

– Slightly raised plates.

– Macroglossia associated with a thickened and hard tongue.

• Heart failure,
• Rhythm disorder, 
• Hepathomegaly…

Diagnosis: biopsy with Congo red staining.

CONCLUSION :

Benign tumors of the oral mucosa are numerous and polymorphic. Their incidence is variable. 

Only a few entities are frequent (epulis, diapneusia).  

The search for signs of malignancy is the first step in the diagnostic process. 

Malignant salivary tumors developing from accessory salivary glands should be treated with caution, as they rarely have a suspicious appearance; for this, histopathological examination should be performed systematically. 

Surgical treatment is indicated for all lesions except for vascular tumors which require additional examinations and specialized management. 

Benign tumors of the oral mucosa.

  Cracked teeth can be healed with modern techniques.
Gum disease can be prevented with proper brushing.
Dental implants integrate with the bone for a long-lasting solution.
Yellowed teeth can be brightened with professional whitening.
Dental X-rays reveal problems that are invisible to the naked eye.
Sensitive teeth benefit from specific toothpastes.
A diet low in sugar protects against cavities.
 

Benign tumors of the oral mucosa.