malignant sgt

Cards (40)

  • Types of Salivary Gland Tumors

    • Recognize the types of SGTs
    • Identify tissue of Origin of each tumor
    • Discuss the histology and management
  • Mucoepidermoid Carcinoma

    Most common salivary malignancy accounting for 29% to 43% of tumors
  • Mucoepidermoid Carcinoma

    • Parotid 45-70% of cases, Palate 18%
    • Histologically classified into low (slowly growing, painless) and high grade (rapidly growing +/- Pain)
    • Partially encapsulated
    • A higher grade correlates with a poorer outcome
    • Low-grade tumors have a protracted course & higher percentage of mucinous cells
    • Epithelial cells predominate in high-grade. The presence of four or more mitotic figures per 10 high-power fields, neural invasion, necrosis, intracystic component <20%, and cellular anaplasia indicate high-grade behavior
  • Mucoepidermoid Carcinoma

    • Parotid>submandibular=minor glands
    • Any age but adults ++
    • Females > males
  • Histopathology of Mucoepidermoid Carcinoma

    • Epidermoid epithelial cells
    • Intermediate epithelial cells
    • Mucous secreting epithelial cells
  • Low Grade Mucoepidermoid Carcinoma

    • Composed of numerous mucus secreting cells arranged around microcystic structure with large & numerous intermediate cells and few epidermoid cells with minimal cellular atypia
  • Intermediate Grade Mucoepidermoid Carcinoma
    • Contains mucus cells & microcystic spaces, but not as numerous as in low grade
  • High Grade Mucoepidermoid Carcinoma

    • Clusters of proliferating epidermoid cells that are more solid with few mucous cells. Mistaken for SCC (mucin Staining)
  • Prognosis of Mucoepidermoid Carcinoma

    Related to histological grade (low grade has benign clinical course but with wide metastasis, while high grade has aggressive course with local & distant metastasis into cervical lymph nodes). Intraoral (IO) tumors has poorer prognosis
  • Treatment of Mucoepidermoid Carcinoma

    1. Stage I & II - Wide local excision
    2. Stage III & IV - Radical excision, +/- neck dissection, +/- postoperative radiation therapy
  • Adenoid Cystic Carcinoma

    Second most common malignancy overall and the first most common malignancy of the submandibular gland. Characterized by slow growth, neurotropism, local recurrence, and distant metastasis
  • Adenoid Cystic Carcinoma

    • Adults; Females>males
    • 5% of major gland tumors, but 25% of minor gland tumours
    • Slow growing, may ulcerate or be painful
  • Histopathology of Adenoid Cystic Carcinoma
    Solid islands, cords, strands of darkly staining epithelial cells in a delicate fibrous connective tissue stroma, however much variation. Notable feature is perineural invasion
  • Histologic Patterns of Adenoid Cystic Carcinoma

    • Cribriform, tubular, or solid, although the histologic patterns may coexist in the same tumor
    • Cribriform pattern has a glandular architecture and is reported to have the best prognosis
    • Solid pattern is more epithelial in nature and is associated with a poorer prognosis
    • Tubular pattern has a clinical prognosis of intermediate nature between the other two patterns
  • Cribriform Pattern of Adenoid Cystic Carcinoma
    Characterized by pseudocystic spaces containing mucin (Swiss cheese pattern)
  • Tubular Form of Adenoid Cystic Carcinoma
    Composed of smallest islands of cells with distinct duct like structure centrally
  • Solid Pattern of Adenoid Cystic Carcinoma

    Shows little duct formation with large islands of small-medium cells with areas of central necrosis indicate aggressive form of the disease
  • Perineural Invasion in Adenoid Cystic Carcinoma
    Spread may occur by emboli along the nerve lymphatics
  • Treatment of Adenoid Cystic Carcinoma
    1. Complete local excision
    2. Tendency for perineural invasion: (facial nerve sacrifice)
    3. Postoperative XRT
  • Prognosis of Adenoid Cystic Carcinoma

    • Local recurrence: 42%
    • Distant metastasis: lung
    • Indolent course: 5-year survival 75%, 20-year survival 13%
  • Acinic Cell Carcinoma

    This tumor has a low-grade behavior and has the best survival rate of any salivary malignancy. Parotid gland was the most common site of origin. Second most common parotid and pediatric malignancy
  • Acinic Cell Carcinoma

    • Gross pathology: Well-demarcated, most often homogeneous
  • Histopathology of Acinic Cell Carcinoma

    Classic multicystic pattern. Stained by PAS. Cells heavily stained. Origin: Intercalated duct & reserve cells. Occurs mainly in the parotid gland, also known as blue dot tumor
  • Acinic Cell Carcinoma
    Lesion is characterized by a benign histomorphologic picture but by occasional malignant behavior
  • Treatment of Acinic Cell Carcinoma

    Complete local excision, +/- postoperative XRT
  • Prognosis of Acinic Cell Carcinoma
    1. year survival: 82%, 10-year survival: 68%, 25-year survival: 50%
  • Histopathological Patterns of Acinic Cell Carcinoma

    • Solid (most common), Papillary, Follicular
  • Malignant Mixed Tumors

    Carcinoma ex-pleomorphic adenoma: Carcinoma developing in the epithelial component of preexisting pleomorphic adenoma
    Carcino-sarcoma: True malignant mixed tumor—carcinomatous and sarcomatous components
    Metastatic mixed tumor: Metastatic deposits of otherwise typical pleomorphic adenoma
  • Carcinoma ex-Pleomorphic Adenoma
    • Malignant degeneration can occur in 3% to 7% of pleomorphic adenomas. The risk of malignant degeneration is estimated at 1.5% in the first 5 years and 9.5% after 15 years
    • Histologic findings include those of benign pleomorphic adenoma with carcinomatous degeneration
    • A typical clinical history includes a longstanding salivary mass that begins to rapidly enlarge, often to substantial size, although many patients have no history of a prior tumor
    • Fixation of mass to surrounding tissue, ulceration & regional lymphadenopathy. Local recurrence
  • Gross Pathology of Carcinoma ex-Pleomorphic Adenoma

    Poorly circumscribed, Infiltrative, Hemorrhage and necrosis
  • Histology of Carcinoma ex-Pleomorphic Adenoma

    Malignant cellular change adjacent to typical pleomorphic adenoma. Carcinomatous component: Adenocarcinoma or Undifferentiated
  • Treatment of Carcinoma ex-Pleomorphic Adenoma
    Radical excision, Neck dissection (25% with lymph node involvement at presentation), Postoperative XRT
  • Prognosis of Carcinoma ex-Pleomorphic Adenoma

    Dependent upon stage and histology
  • Clear Cell Tumor

    Include: Clear cell carcinoma & Epimyoepithelial carcinoma. Low grade tumor (predominantly in minor SG) as submucosal mass in palate. Abundant clear cells
  • Treatment of Clear Cell Tumor
    Local excision with High recurrence
  • Squamous Cell Carcinoma of Salivary Glands

    Limited to major salivary glands (SM). Obstructive sialadenitis is predisposing factor. Well to moderately well-differentiated with no evidence of mucin production. 1.6% of salivary gland neoplasms. 7th-8th decades. M:F = 2:1. Must rule out high-grade mucoepidermoid carcinoma, metastatic SCC to intraglandular nodes, or direct extension of SCC
  • Polymorphous Low Grade Adenocarcinoma

    Low grade malignancy with low risk of recurrence & metastasis. Origin: Reserve cells in most proximal portion of salivary duct. Myoepithelial differentiated cells appear in this neoplasm. Exclusive in minor salivary glands (palate)[second most common malignancy of MSG]
  • Polymorphous Low Grade Adenocarcinoma
    • Firm, elevated, non-ulcerated nodular swelling. 1-4 cm, slow growth in long duration (yrs). Metastasis in 10% of patients
  • Morphologic Diversity of Polymorphous Low Grade Adenocarcinoma
    Solid, glandular, cribriform, ductular, tubular, trabecular, cystic
  • Treatment of Polymorphous Low Grade Adenocarcinoma
    Complete yet conservative excision