ORAL PATHOLOGY II: MALIGNANT SALIVARY GLAND TUMOR

 Mucoepidermoid carcinoma  Intraosseous mucoepidermoid carcinoma  Acinic cell carcinoma  Mammary analogue secretory carcinoma  Malignant mixed tumors  Adenoid cystic carcinoma  Polymorphous low grade adenocarcinoma  Salivary adenoma NOS

MUCOEPIDERMOID CARCINOMA

Epithelial mucin-producing tumors.

Neoplastic mucous cells contain neutral glycoproteins, acidic mucins, and sulfomucins

Epidermoid cells contain keratin intermediate filaments.

MUCOEPIDERMOID CARCINOMA

Arise from reserve cells in the interlobular and intralobular segments of the salivary duct system

MUCOEPIDERMOID CARCINOMA

May also arise centrally within the mandible, presumably from embryonically entrapped salivary element

MUCOEPIDERMOID CARCINOMA

MOST COMMON MALIGNATN TUMOR OF SALIVARY GLAND

34% of parotid malignancies

20% of submandibular gland malignancies

30% of minor salivary gland malignancies

MUCOEPIDERMOID CARCINOMA

Most common salivary gland malignancy of childhood.

MUCOEPIDERMOID CARCINOMA

Clinical features:



Most common site: parotid gland (60-90%)



3rd to 5th decades



M=F

MANIFESTATION GRADE: Low-grade

prolonged period of painless enlargement

MANIFESTATION GRADEHigh-grade

grow rapidly and are often accompanied by pain and mucosal ulceration; may present with evidence of facial nerve involvemen

MUCOEPIDERMOID CARCINOMA

Often resembles an extravasation or retention-type mucocele that may at times be fluctuant as a result of mucous cyst formation.

MUCOEPIDERMOID CARCINOMA



In the mandible or maxilla: radiolucent lesions within the molar and premolar area

MUCOEPIDERMOID CARCINOMA

Histo:

Lobular infiltration of adjacent tissue

Well circumscribed

MUCODERMOID CARCINOMA: Low-grade

Histo:

Composed of mucus secreting cells arranged around microcystic structures, with an intermingling of epithelial, or "intermediate," cells

MUCODERMOID CARCINOMA: HIGH GRADE

Characterized by neoplastic cell clusters composed chiefly of epidermoids that are more solid with fewer cystic spaces and scattered mucous cells

MUCODERMOID CARCINOMA: INTERMEDIATE GRADE

Lie histologically and biologically between low- and high-grade lesions.

Mucous cells and microcystic spaces are apparent, but not as numerous as in low-grade lesions.

MUCOEPIDERMOID CARCINOMA

Prognosis

Low-grade

Characteristically follow a benign clinical course

>95% 5 yr survival rate

High-grade

40% 5 yr survival rate

MUCOEPIDERMOID CARCINOMA

Treatment

Low grade → surgery

High grade → surgery with postop radiotherapy; neck dissection

INTRAOSSEOUS MUCOEPIDERMOID CARCINOMA

AKA central mucoepidermoid carcinoma

INTRAOSSEOUS MUCOEPIDERMOID CARCINOMA

Most common and best recognized intrabony salivary tumor

INTRAOSSEOUS MUCOEPIDERMOID CARCINOMA

Most common and best recognized intrabony salivary tumor

INTRAOSSEOUS MUCOEPIDERMOID CARCINOMA

Pathogenesis



Most likely source: odontogenic epithelium



Mucus-producing cells are common in odontogenic cyst linings (dentigerous cysts)



Develop in association with impacted teeth or odontogenic cysts.

NTRAOSSEOUS MUCOEPIDERMOID CARCINOMA

Clinical and Radiographic Features

Middle-aged adults

F > M

Mandible > maxilla → molar-ramus area

INTRAOSSEOUS MUCOEPIDERMOID CARCINOMA

Most frequent symptom: cortical swelling → some lesions may be discovered as incidental findings on radiographs.



Pain, trismus, and paresthesia reported less frequently

INTRAOSSEOUS MUCOEPIDERMOID CARCINOMA

Clinical and Radiographic Features

Unilocular or multilocular radiolucency with well-defined borders → some have irregular and ill-defined area of bone destruction

Some cases are associated with an unerupted tooth → may mimic an odontogenic cyst or tumor.

INTRAOSSEOUS MUCOEPIDERMOID CARCINOMA

Histopathologic Features

Similar to soft tissue counterpart

Most tumors are LOW GRADE lesions → high-grade have been reported within the JAWS.

INTRAOSSEOUS MUCOEPIDERMOID CARCINOMA

Treatment and Prognosis

Primary treatment: radical surgical resection → adjunctive radiation therapy is sometimes

Metastasis reported in 12% of cases

Prognosis: good → 10% die due to local recurrence

ACINIC CELL CARCINOMA

Occurs in major salivary gland → especially PAROTID GLAND (bilateral involvement in 3% of cases)

ACINIC CELL CARCINOMA

ACINIC CELL CARCINOMA

Within the oral cavity most cases occur in the palate and buccal mucosa

From the intercalated duct reserve cell

ACINIC CELL CARCINOMA

Accounts for 14% of all parotid gland tumors and 9% of the total of salivary gland carcinomas of all sites.

ACINIC CELL CARCINOMA

Clinical features:

Found in all age groups (peak incidence: 5th-6th decades)

M=F

Slow growing lesion less than 3 cm in diameter.

Pain is a common presenting symptom.

ACINIC CELL CARCINOMA

Histo:

Typically grows in a solid pattern → 1/3 of lesions show a microcystic growth pattern

Tumor cells are uniform and well differentiated.

ACINIC CELL CARCINOMA

Treatment and Prognosis

Surgery is the preferred treatment

Does not metastasize but reccurs

Survival rates:

5 yrs – 89%

20 yrs – 56%

MAMMARY ANALOGUE SECRETORY CARCINOMA

A recently described malignancy primarily occurring in the parotid gland

MAMMARY ANALOGUE SECRETORY CARCINOMA

Rare tumor sharing some morphologic similarities with acinic cell carcinoma and several histologic, immunophenotypical and genetic features with secretory carcinoma of the breast.

MAMMARY ANALOGUE SECRETORY CARCINOMA



Have a lobulated growth pattern composed of microcystic tumor and solid structures formed by cells that do not contain PAS-positive secretory zymogen granules

MAMMARY ANALOGUE SECRETORY CARCINOMA

Clinical behavior ranges from slow growth and infrequent recurrence after surgical resection to aggressive tumors associated with widespread metastasis and death.

MALIGNANT MIXED TUMORS

Malignancy in which both epithelial and the mesenchymal components are malignant

MALIGNANT MIXED TUMORS

Site: parotid

ADENOID CYSTIC CARCINOMA

Clinical features



Accounts for approximately 23% of all salivary gland carcinomas



50% to 70% occur in minor salivary glands of the head and neck

ADENOID CYSTIC CARCINOMA

glands the parotid gland is most often affected

5th-7th decades

M=F

ADENOID CYCTIC CARCINOMA



Unilobular mass that is firm on palpation, occasionally with some pain or tenderness



Slow growing

ADENOID CYCTIC CARCINOMA



Facial nerve weakness or paralysis may occasionally be the initial presenting symptom, especially in late-stage lesions

ADENOID CYSTIC C



Bone invasion occurs often



Distant spread to lungs common



Typically infiltrates perineural spaces



Intraorally → ulceration of the overlying mucosa

ADENOID CYSTIC CARCINOMA: Cribriform pattern

HISTO

Best recognized pattern → prototype

Pseudocystic spaces contain sulfated mucopolysaccharides characterized by multilayered or replicated basal lamina material

ADENOID CYSTIC CARCINOMA: Tubular form

Composed of smaller islands of cells with distinct ductlike structures centrally.

ADENOID CYSTIC CARCINOMA: Solid basaloid pattern



Shows little duct formation



Composed of larger islands of small to medium-sized cells with small, dark nuclei.



May also show more pleomorphism than the other forms and is associated with a poorer outcome.

ADENOID CYSTIC CARCINOMA

Treatment and Prognosis

Survival rates

5 years → 70%

15 years → 10%.

Tx of choice:

Surgery

Parotid → superficial parotidectomy or superficial and deep lobectomy

Lntraorally → wide excision, often with removal of underlying bone

Radiation therapy → management of primary disease and recurrences

Multiple-agent chemotherapy has shown some promise in the management of widely metastatic disease.

POLYMORPHOUS LOW GRADE ADENOCARCINOMA

KNOWN BEFORE AS: lobular carcinoma of salivary glands and terminal duct carcinoma

POLYMORPHOUS LOW GRADE ADENOCARCINOMA

Low-grade malignancy with a relatively indolent course and low risk of recurrence and metastasis.

From reserve cells in the most proximal portion of the salivary duct

POLYMORPHOUS LOW GRADE ADENOCARCINOMA

Clinical features:

Mean age 59 (5th to 8th decades)

M=F

Appears almost exclusively in minor salivary glands → most frequently reported site: palate

POLYMORPHOUSE LOW GRADE ADENOCARCINOMA

Firm, elevated, nonulcerated nodular swellings that are usually nontender



Wide size range: 1-4 cm



Slow growing → metastasis noted at time of diagnosis

POLYMORPHOUS LOW GRADE ADENOCARCINOMA

Histo:



Absence of encapsulation with infiltrating streams of cells and a general lobular morphology



Composed of a homogeneous population of cells with prominent, bland, often vesicular nuclei and minimal cytoplasm arranged in lobules and solid nests

POLYMORPHOUS LOW GRADE ADENOCARCINOMA

Treatment

Conservative surgical excision

SALIVARY ADENOMA NOS

Clinical and Features

Common site: parotid gland → followed by the minor glands and the submandibular gland

SALIVARY ADENOMA NOS

Present as asymptomatic masses or cause pain or facial nerve paralysis.

SALIVARY ADENOMA NOS

Histopathologic Features



Highly variable → demonstrates features of a glandular malignancy with evidence of cellular pleomorphism, an infiltrative growth pattern, or both

Exhibit a wide spectrum of differentiation → from well-differentiated, low-grade neoplasms to poorly differentiated, high-grade malignancies

SALIVARY ADENOMA NOS

Treatment and Prognosis

Patients with early-stage, well-differentiated tumors appear to have a better prognosis

Survival rate is better for tumors of the oral cavity than for those in the major salivary glands.

10-year survival rate for parotid tumors → 26% to 55%

10-year survival rate for intraoral tumors → 76%