Benign Mesenchymal Tumors (Exam 2)

Question 1

What kind of soft tissues do mesenchymal tumors originate from?

Answer 1

Fibrous
Adipose
Nerve
Blood
Lymph
Muscle

Question 2

This is a collagen deposition secondary to chronic trauma. Common sites include the buccal mucosa and tongue. Described as Smooth-surfaced, dome-shaped
nodule, can be sessile or pedunculate.  Most art 1.5 cm or less in diameter. They are asymptomatic unless traumatized from biting. Histopathologically they are a nodular mass of dense fibrous connective tissue.

Answer 2

Fibroma
Tx: Conservative excision, Recurrence is rare
Variations: Frenal tag - small, innocuous growth easily diagnosed clinically, no treatment is usually necessary. Retrocuspid Papilla - Bilateral papular lesions on the gingiva lingual to the mandibular canines

Question 3

This is also known as denture epulis, epulis fissuratum, or denture-induced fibrous hyperplasia. It’s caused by the flange of an ill-fitting denture, poor denture hygiene and wearing a denture 24 hours a day. Can also be seen on habitual mouth breathers. Site is the central region of hard palatal mucosa. May have a central fissure. Described as Numerous asymptomatic red papules

Answer 3

Inflammatory Fibrous Hyperplasia (IPH) or Denture papillomatosis from a maxillary complete denture
Tx: Early lesions - removal of the denture may allow the erythema and edema to subside. The condition also may show improvement after topical or systemic anti fungal therapy. Consider excising the hyperplastic tissue before fabricating a new denture. Various surgical methods have been used.

Question 4

This is not a true granuloma and it’s not really pyogenic. It is unrelated to infection. . It is exuberant formation of hype plastic granulation tissue in reaction to local trauma. Frequently occurs during pregnancy. Common sites include Gingiva (~80%), lips, tongue. Described as rapidly growing, painless, reddish mass, often ulcerated. Bleeds easily.

Answer 4

Pyogenic Granuloma

Tx: Excise, remove irritants; 15% recur

Question 5

What are the three things that grow out of a socket (two of them are bad)?

Answer 5

1. Epulis granulomatosa 2. Lymphoma

3. Metastatic disease

Question 6

Microscopically, this is granulation tissue with numerous benign multinucleated giant cells. Only found on gingiva and
edentulous alveolar ridge. Caused by local irritation or trauma. Described as Painless mass with a dusky-purple hue.

Answer 6

Peripheral Giant Cell Granuloma

Tx: Excise, remove irritants; 15% recur

Question 7

Microscopically, this is cellular fibrous connective tissue with variable amounts of calcification. It’s only found on the gingiva. It’s a reactive lesion. Described as Painless firm coral-pink mass, may be ulcerated.

Answer 7

Peripheral Ossifying Fibroma

Tx: Excise, remove irritants; 15% recur

Question 8

What 3 things could bumps on the gums be (3 P’s)?

Answer 8

1. Pyogenic granuloma
2. Peripheral giant cell granuloma
3. Peripheral ossifying fibroma

Question 9

This is a benign tumor of adipose tissue, found in adults. Common sites: head and neck; occasionally found intramurally. Described as slow-growing, non-tender, soft, doughy, yellow if close to the surface. Microscopically appears as a demarcated or encapsulated collection of mature fat cells

Answer 9

Lipoma
Tx: Enucleation or conservative surgical excision. Little or no tendency to recur. No evidence of malignant transformation.

Question 10

This represents an uncommon reaction to the sectioning of a nerve. It’s not a true neoplasm, it’s a reactive proliferation of nerve tissue after damage of the nerve bundle. Commons sites: Tongue, buccal vestibule, mental foramen area. Described as smooth-surfaced, dome-shaped papule, usually less than 1 cm. May be tender on palpation (~1/4 to 1/3 re painful). Pain can be intermittent or constant; mild tenderness or burning to severe radiating pain. Area of mental nerve frequently painful, especially when impinged on by a denture or palpated. Microscopically, a tangled mass of peripheral nerve fibers is seen, usually set in a collagenous background

Answer 10

Traumatic Neuroma
Tx: Surgical excision, including a small
portion of the proximal nerve bundle. Recurrence is not common.
Px: Good. Pain may persist or return at a later date

Question 11

This is a benign tumor of caused by a proliferation of spindle-shaped Schwann cells (Well-developed connective tissue capsule surrounds axons of peripheral nerves). Most are identified in adults. Common sites include lips, tongue, buccal mucosa. Described as slow-growing, solitary, encapsulated,
rubbery-firm, non-tender mass. May push on the nerve or other structures. May be seen centrally within the mandible and may cause expansion; could appear as a unilocular or multilocular radiolucency.
Two patterns seen microscopically: Antoni A - palisaded nuclei arranged around Verocay bodies (acellular zones made of reduplicated basement membrane and cytoplasmic processes), Antoni B – less organized, sometimes myxoid

Answer 11

Neurilemoma (Schwannoma)
Tx: Treatment consists of conservative excision. Lesion usually “shells out” due to dense connective tissue capsule. Virtually no tendency to recur. Extremely rare malignant transformation.

Question 12

This is a benign tumor of neural fibroblast origin. Over 90% are solitary; remainder are multiple and associated with neurofibromatosis. Skin is most common location, but oral cavity lesions are not uncommon. Most common intraoral sites are:  Tongue, Buccal mucosa.
Described as soft, dome-shaped, non-tender, superficial nodule affecting skin or
mucosa. Demarcated, but unencapsulated. Can occur centrally within bone and appear as a unilocular or multilocular radiolucency.
Microscopically: Collection of fibroblastic cells that have wavy nuclei. Usually quite a few mast cells are seen within the lesion. Lesional tissue tends to mingle with the adjacent normal tissue

Answer 12

Neurofibroma
Tx: simple, conservative excision
Px: generally good. Uncommon possibility of malignant transformation to malignant peripheral nerve sheath tumor; especially rare for small, superficial lesions

Question 13

Tell me about Neurofibromatosis.

Answer 13

There are several types of neurofibromatosis. It is one of the
most common autosomal genetic problems that affects humans.

Neurofibromatosis Type 1 (NF1) occurs at a frequency of approximately 1 in 3,000 live births.

Half are transmitted as autosomal dominant trait; half
appear to be new mutations.

Highly variable gene expression – some cases are very mild, others are quite severe.

Variety of manifestations, both cutaneous and oral.

Café-au-lait spots - Light brown (the color of coffee with milk) macules with smooth (“coast of California”) borders. Usually 6 or more, greater than 1.5 cm in the adult patient.

Multiple neurofibromas
These can be small, discrete lesions or massive, pendulous ones known as “plexiform neurofibromas,” which feel like a “bag of worms.”

Oral findings (may be present in 72% - 92% of cases of NF1): Neurofibromas: tongue, gingivae or bone
Enlargement of fungiform papillae has been reported, however specificity for NF1 is unknown.

Tx: removing traumatized neurofibromas or
disfiguring lesions
Genetic counseling
Follow for potential malignant transformation

Px: Fair to guarded, If malignant transformation occurs, prognosis is poor, usually a malignant peripheral nerve sheath tumor (MPNST)

Question 14

This is a rare tumor seen most often in the first year of life. Most are benign and develop in the anterior maxilla. The grow rapidly. Described as brown or black in color, radiolucency of anterior maxilla (characteristic), deciduous maxillary incisor is pushed labially, appearing as a “tooth floating in space.” microscopically, proliferation of small, dark, neuroectodermal-appearing cells that are in nested aggregates
 Surrounded by plump, epithelioid cells with vesicular nuclei, which produce melanin

Answer 14

Melanotic Neuroectodermal Tumor of Infancy

Tx: Conservative excision is usually curative

Px: Good. Sporadic reports of aggressive behavior are probably over- represented in the literature. Clinical follow-up is prudent.

Question 15

These are S-100 positive. They develop on any cutaneous or mucosal surface, but 40% occur on the tongue, mucosa and floor of mouth may be affected. Described as slow-growing, demarcated (though unencapsulated), non-tender submucosal nodule, most are less than 1 cm. in size.
Microscopically, collection of mesenchymal cells with a granular-appearing cytoplasm. PEH (pseudoepitheliomatous hyperplasia) is present in about 30% - 50% of these tumors – may be mistaken for squamous cell carcinoma microscopically

Answer 15

Granular Cell Tumor
Tx: Conservative excision is usually curative
Px: Excellent

Question 16

This is a rare lesion of undetermined histogenesis. Often found at birth on the maxillary ridge of female babies. It’s often lateral to the midline. Described as smooth-surfaced, often pedunculate. Vary in size. Microscopically, shows a benign proliferation of cells having granular cytoplasm. No pseudoepitheliomatous hyperplasia. No S -100 positivity

Answer 16

Congenital Epulis

Tx: Conservative excision. No tendency to recur. Some reports of spontaneous involution without surgery.

Question 17

What are hemangiomas?

Answer 17

Most common tumor of childhood

Benign tumors of infancy that have rapid growth of endothelial cell proliferation, followed by gradual involution. 50% resolve by age 5, 90% resolve by age 9.

Most hemangiomas are not recognized at birth but arise by 8 weeks.

Exception is the non-involuting congenital hemangioma; these are fully developed at birth and do not involute

Some consider hemangioma to be a vascular hamartoma rather than a
true neoplasm

Head and neck region is frequently affected. Tongue is most common intramural site.

Usually red in color, but can range through various shades of purple, depending on the caliber and depth of vessels. Most are elevated, but macular lesions are also seen. Variable in size.

Question 18

What are vascular malformations?

Answer 18

Structural anomalies of blood vessels with normal endothelial cell turnover. These are present at birth and persist through life.

They grow proportionately with the patient.

Examples include:
port wine stain (capillaries) - nevus flames). Can occur anywhere on the body. Most are not associated with other abnormalities. Seen in some rare syndromes, including Encephalotrigeminal Angiomatosis (Sturge-Weber)
venous malformation (blue)
arteriovenous malformation (bruit, thrill)

Question 19

Why is it important to distinguish between Hemangiomas and

Vascular Malformations?

Answer 19

To differentiate between lesions that will resolve versus those that are permanent, i.e. whether to treat.

Diascopy may be helpful in determining whether a red lesion is
due to extravasated blood or to blood that is contained within vessels. Press on lesion with glass slide – blood within vessels will be pushed into adjacent vessels and lesion will blanch.

Tx: Surgical excision, cryotherapy, embolization, lasers or use of sclerosing agents if cosmetically unacceptable. If lesion impairs vision, treat as soon as possible. Otherwise, wait until child is at least 6 years of age.

Question 20

This is a congenital abnormality, not an inherited or genetic problem. It’s a dermal capillary vascular malformation affecting superficial and deeper tissues in region of cranial nerve V. Patients exhibit port wine stain in distribution of 1st, and sometimes 2nd or 3rd, division of CN V. Involvement of deeper soft tissues as well as meninges of brain. If port wine stain involves the entire distribution of V1 risk for neurologic and ocular involvement is 78% (seizures, mental retardation, and hemiplegia).
Radiographic finding of “tram- line” calcifications seen on skull film. Parallel calcifications probably represent the calcified walls of abnormal blood vessels.

Answer 20

Encephalotrigeminal Angiomatosis

Question 21

This is a benign neoplasm of lymphatic vessel differentiation. It is often present at birth. Tongue is most common intramural site. Surface has a vesicular appearance, similar to “frog eggs” or “tapioca pudding.”

Answer 21

Lymphangioma
Tx: depends on size of lesion. More difficult to treat than hemangioma
because it is often difficult to discern the borders of the tumor. Surgical excision is the treatment of choice. Relatively high recurrence rate – up to 40% in some series.

Variations: Cystic Hygroma - a very large lymphangioma. May affect the neck, mediastinum, axilla and the oral cavity. Important because this lesion may cause airway obstruction, particularly if it becomes secondarily infected.

Question 22

This is a benign tumor of smooth muscle differentiation. Most in the oral region probably arise from vascular smooth muscle. Most common in the upper lip, buccal mucosa and palate.
Described as well-demarcated, rubbery firm, less than 1 cm in diameter. May have a reddish or purplish color due to their vascular nature.
Microscopically, benign proliferation of cells that
resemble smooth muscle.
Spindle-shaped, with cigar-shaped nuclei and eosinophilic cytoplasm.
No significant atypia, and no mitotic activity.
Positive for markers of muscle differentiation.

Answer 22

Leiomyoma
Tx: conservative excision
Px: excellent. Virtually no chance of recurrence

Question 23

This is a very rare, benign tumor of skeletal muscle differentiation. Most rhabdomyomas arise in the heart (“cardiac rhabdomyoma”) and are associated with the syndrome tuberous sclerosis. Extra-cardiac rhabdomyomas usually develop in the head and neck region. Mostly in middle-age and older males. Described as non-tender, well-circumscribed mass in the submandibular or base of tongue region.
Microscopically, round to polygonal cells, granular eosinophilic cytoplasm
Multiple vacuolated cells, many with spider-web appearance.

Answer 23

Rhabdomyoma
Tx: surgical excision is
appropriate. Recurrence has been reported, but is not common