Oral pathology sheet # 12 - Amal abu 3awwad

by **Shadi Jarrar** 5/8/2011, 4:58 pm

بسم الله الرحمن الرحمن

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http://www.4shared.com/document/8hxwlEcy/oralpatho12.html
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Today’s lecture we will talk about:

*Connective Tissue Tumors

*Oral Epithelial Tumors

Connective Tissue Tumors

v Neural tissue

(The presentation of all the benign connective tissue tumors are the same; all appear as submucosal nodules):

· Neurilemmoma (Schwannoma) :

Clinically:

- Movable because it is encapsulated

- The mucosa is smooth with normal color

- Most common site is the dorsal surface of the tongue, but could arise within the bone in the inferior alveolar nerve ( two tumors arise in the inferior alveolar nerve appearing as radiolucency inside the mandible ; Neurofibroma and Neurilemmoma )

Histologically:

- encapsulated tumor, no nerve fibers within the lesion as compared with Neurofibroma

- Histopathology : there are two areas ( two distinct patterns of cellular architecture) ;

Antoni A: it has parallel rows of spindle elongated cells - it is a characteristic (diagnostic) feature of Schwannoma .

Antoni B: it is a disorganized area, contains mucinous microcystic stroma.

· Multiple Endocrine Neoplasia Syndrome , type 3 ( or type 2b )

- We mentioned it when we talked about Macroglossia, since it is one of the causes, because it appears as multiple Submucosal nodules (or neuromas) on the lateral border of the tongue or on the lip. These occur before the development of other tumors in the endocrine system, especially in the thyroid (Medullary Carcinoma of the thyroid) and Phaeochromocytoma. All these manifestations help in the diagnosis of Multiple Endocrine Neoplasia Syndrome, by taking a biopsy from the neuromas and this may help in early management which might include doing thyrodectomy as early as possible.

· Traumatic Neuromas

- It is a nerve that got traumatized, leading to proliferation occurring at the proximal segment of the nerve. We also see nerve fibers, Schwann cells and perineural fibroblasts forming a scar tissue ( mass ), containing the proximal segment of the traumatized nerve.

- This mass appears in the oral cavity as a nodule, characterized by being tender, painful (because it contains a nerve segment) with palpation.

- The most common nerve is the mental nerve, especially in edentulous patients, caused by resorption of the ridge, so the nerve gets traumatized from the denture, where it gets out of the canal.

Histologically:

- It resembles a Neuroma; collection of nerve fibers, fibrous tissue, fibroblasts, and Schwann cells (normal nerve tissue).

v Muscle Tissue

· Of the skeletal muscles :

Rhabdomyomas:

- It is very rare

- Most common site is the heart, the tongue is the second most common site

· Of the smooth muscles:

Leiomyoma:

- Most common site is the uterus.

- Orally; they arise from smooth muscles of blood vessels , we call them angiomyomas

· Rhabdomyosarcoma & Leiomyosarcoma:

- Very rare to discuss

· Granular Cell Tumor

- It is one of the nerve tissue tumors, originating from Schwann cells. (In the past they used to consider it as a muscle tumor - they thought it originated from skeletal muscle tissue).

- Appears on the dorsal or lateral border of the tongue and on the soft palate as a submucosal nodule.

- It is firm, painless, slowly growing.

- All these tumors can NOT be differentiated clinically; we need to take a biopsy to confirm diagnosis. We put a differential diagnosis when we see a Submucosal nodule, it could be lipoma, neurofibroma, Schwannoma, granular cell tumor or other benign tumors.

(Submucosal nodule means: to see a normal mucosal surface with swelling coming from underneath from the connective tissue)

- Sometimes it appears as multiple masses in the tongue or the body

- No specific age or gender

Histologically:

- They called it granular cell tumor because it consists of diffuse sheets of large cells. These cells contain eosinophilic granules ( lysosomes ) in the cytoplasm .

- Not encapsulated, so we can see the granular cells deep within the muscle fibers of the tongue or on the surface epithelium between the rete ridges ( epithelial processes )

- Pseudoepitheliomatous hyperplasia: there is hyperplasia in the surface epithelium giving the appearance of Squamous cell carcinoma. We confirm the diagnosis by taking a biopsy; the granular cells extend between the epithelial processes.

v Malignant lymphoma

· Hodgkin’s disease

- Accounts for 30% of all malignant lymphomas

Clinically:

- Differs from non-Hodgkin’s disease that it originates in the lymph nodes (especially the cervical lymph nodes), this helps in diagnosis.

- More common in males , 3^rd decade of life

- Starts as swelling in a single lymph node (cervical lymph node), a painless swelling that progressively enlarge (so it is not infection). then enlargement occur to the adjacent lymph nodes or in other places ( extra-nodal sites; not in lymph nodes )

- Associated with low grade fever, night sweats

- It rarely affects extra-nodal sites so it rarely affects the mucosa of the oral cavity. If it occurred intra-orally it would be an extension from other site as a late stage of a widely disseminated disease.

- Unknown etiology, it could be genetic susceptibility or viral infection (Epstein- Barr virus)

Histologically:

- Reed-Sternberg Cells.

- There are 4 histological variants , we depend on them in prognosis :

1. Lymphocyte predominance : 5-year survival rate is 90%

2. Lymphatic depletion : survival rate is 20% ( this type consists mainly of Reed-Sternberg cells, it doesn’t contain lymph cells )

3. Nodular sclerosis: 70%

4. Mixed cellularity: 60%

· Non-Hodgkin’s lymphomas:

- mainly affects adults

- classification varies; depends on whether we concentrate on cell of origin, immunohistochemical stains or on cytological features

- rarely affect the head and neck region, and when it does it is secondary to a disseminated disease

- It is a primary disease when it develops, mainly in the cervical lymph nodes, and Waldeyer’s ring ( the lymphatic tissue of the posterior part of the oral cavity ). Or it could be Extra-nodal in origin, arising in the oral soft tissues; mucosa, salivary glands ( parotid gland ) or within the mandible and the maxilla

- Mucosal lesions appear as fleshy swelling with ulceration, and destruction of the teeth and the adjacent tissues ( signs of malignancy)

- The most common tumor of the oral cavity in AIDS patient is Kaposi's Sarcoma, and the second most common tumor is Non-Hodgkin’s lymphoma

Burkitt’s lymphoma:

- it is a type of Non-Hodgkin’s lymphoma

- affects extra-nodal sites, especially the jaws and the abdomen

- etiology: translocation of chromosomes, the causative agent is the Epstein-Barr virus ( EBV)

- 3 types :

1. African endemic

- Affect young age, 1^st decade of life, affecting males more than females

- Cause massive tumor in the maxilla, rapidly growing, destruction, ulceration, displacement of teeth and resorption

- Lymphoma in the abdomen

- Strong association with EBV

- Malaria helps in occurrence( cofactor ), because it reduces the immune system resistance to EBV

2. Non-African , non-endemic

- In Europe, USA, Asia

- Mainly arises in the abdomen. It affects the jaws in 20% of the cases ( affecting the maxilla and the mandible )

- Not associated with EBV, but has a similar chromosomal abnormality as the African Endemic type

3. AIDS- associated

- Affects the palate and the gingiva

- It is the second most frequent tumor in AIDS patients

Histologically:

- Starry-sky pattern; in which we see lymphocytes, and macrophages scattered among them

** All of the above tumors originated from the connective tissue

Oral epithelial tumors

- Tumors derived from the oral Epithelial tissue could be benign or malignant tumors

v Squamous papilloma

- Common benign lesion

- Etiology: human papilloma virus ( types 6, 11)

- There are more than 69 known HPV subtypes, only types 6 and 11 cause oral Squamous papilloma

Clinically

- Sessile or pedunculated

- White ( if the surface epithelium keratinized ), or pink ( if not keratinized )

- Small in size ( < 1cm ) and stop increasing to a certain size

- Cauliflower-like lesion, finger like projections.

(Clinical appearance helps in diagnosis)

- Usually solitary, but could be multiple

- Mainly affecting adults

- No specific location in the oral cavity

- Not infectious ( compared to skin Verruca Vulgaris )

Histologically:

- Hyperplasia of the epithelium forming the finger-like projections. So, we have a thick papillary layer o-keratinized or non-keratinized epithelium ( relating to the clinical appearance; white or pink )

- Supported with a thin core of fibrovascular stroma

- Hyperplasia in the basal cell layer leading to mitotic activity

- No potential for malignant changes into squamous cell carcinoma

v Verruca Vulgaris ( common warts )

- It is a skin lesion, affecting the skin of the hands and fingers of children

- Multiple, hard to get rid of

- Etiology: HPV ( 2 , 4)

- Auto-inoculation of the oral cavity from the skin of fingers to the mouth

Clinically:

- Appearance resembles Squamous papilloma, but differs in that:

. It is always white in color

. Affects mainly children

. Multiple in the oral cavity, while squamous papilloma is solitary

. With clinical examination, we must examine the skin of hands and fingers

-if there are a lot of lesions present, the patient may have problems with his/her immunity (for example, AIDS patients )

Histologically

- Similar to Squamous papilloma; hyperkeratosis, hyperplasia, prominent granular cell layer ( due to thick keratin layer )

- Koilocytes, which are human papilloma infected cells ( the virus is inside them, confirmed with immunohistochemical stains), having perinuclear clear area around the nucleus

- Differ from Squamous papilloma by having the cupping effect, in which the hyperplastic rete ridges slope inside towards the center of the lesion like a cup ( but we mainly depend on the above mentioned differences )

v Condyloma Acuminatum ( Venereal Wart )

- Affect the genital areas, transformed to the oral cavity by Oro-genital contact

- Etiology: HPV ( 6, 11, 16 )

Clinically:

Multiple pink (not white) nodules that grow and join together to form soft pedunculated or sessile papillary lesions

(So the difference here is that they are pink and they may join together affecting large confluent areas)

Histologically:

- The surface is either non-keratinized or para-keratinized

- Hyperplasia in basal cell region leading to broad elongated rete ridges

- Acanthosis, koilocytosis and high mitotic activity in the epithelium

- Supported by fibrovascular stroma

(Squamous papilloma, Verruca Vulgaris and Condyloma Acuminatum are all similar in histology, but differ in the clinical features, in the history and effects on other sites)

v Focal Epithelial Hyperplasia ( Heck’s disease )

- We see it in native Indians mainly because they have genetic susceptibility ( that’s why only affects these areas )

- Etiology : HPV ( 13, 32 )

- It first appears in young age ( children ), but it regress with age without treatment

Clinically:

- Multiple small elevated epithelial plaques (elevated wide areas)

- Affects the Lip or buccal mucosa

Histologically:

- Epithelial hyperplasia and Koilocytosis ( the HPV is present inside the cells )

v Squamous Cell Carcinoma

- It accounts for 90% of malignant tumors in the oral cavity. It is the most common and most important tumor of the oral cavity.

Incidence: accounts for 30-40% of malignant tumors that affect the body in India

Globally: 4^th commonest cancer in men & 6^th in females

Age: 98% > 40 years of age, and the incidence increases with age ( rare to see cases in patients younger than 40 years old )

Gender: in the past it used to be more common in males than in females, but now the difference reduced because of the etiological or predisposing factors (increase in females smoking). Intra-orally the male female ratio is 3:2, but in the Lip it is 8:1 (M: F) (there is still a huge difference in the lip, because of exposure to the sun)

Site:

Most common site is the lip.

Intra-orally, it affects the tongue (especially the lateral border of the tongue ), the buccal mucosa. 70% of the cases occur in the U-shaped area (which is the ventral surface of the tongue, lateral border of the tongue, floor of the mouth, lingual gingiva and the retro molar area). Although it accounts for 20% of the surface area of the oral cavity , the deposition of toxic materials (from smoking and alcohol ) in this area is more than other areas in the oral cavity. This explains why cancers mainly occur on the lateral border of the tongue, floor of the mouth and the lingual gingiva. It rarely affects the hard palate and the central part of dorsum of the tongue.

Lect. # 12

1/8/2011

Amal Abu Awwad