Salivary Gland Tumors

Salivary Gland Tumors - Glandular Grand Tour

• Classification: Benign (e.g., Pleomorphic Adenoma, Warthin's) vs. Malignant (e.g., Mucoepidermoid Ca, Adenoid Cystic Ca).
• Location: Parotid (~80%) > Submandibular (~10-15%) > Sublingual/Minor (~5-10%).

⭐ Parotid gland is the most common site for salivary gland tumors (approx. 80%).

• Presentation: Often painless mass. Facial nerve palsy ⚠️ (parotid malignancy sign).
• Diagnosis: FNA, imaging (USG, CT/MRI).
• 📌 Rule of 80s (Parotid): 80% of tumors, 80% benign, 80% of benign are Pleomorphic Adenomas.

Salivary Gland Tumors - Gentle Giants Parade

• Benign Tumors (80%)
  • Pleomorphic Adenoma (Benign Mixed Tumor)
    • Most common salivary gland tumor (overall & benign).
    • Parotid > Submandibular > Minor salivary glands.
    • Painless, slow-growing, mobile mass.
    • Histology: Epithelial & myoepithelial cells in a variable stroma (📌 "Pleomorphic" = diverse appearance).
    • Risk of malignant transformation (Carcinoma ex pleomorphic adenoma).

    ⭐ Pleomorphic adenoma is the most common salivary gland tumor overall and the most common benign salivary gland tumor.

  • Warthin's Tumor (Papillary Cystadenoma Lymphomatosum)
    • Second most common benign tumor; almost exclusively in parotid.
    • Strong association with smoking.
    • Often bilateral; more common in older males.
    • Histology: Papillary cystic structures with double layer of oncocytic epithelial cells & lymphoid stroma.
• Malignant Tumors (20%)
  • Mucoepidermoid Carcinoma (most common malignant overall, most common in parotid)
  • Adenoid Cystic Carcinoma (Perineural invasion common ⚠️; cribriform pattern)

Salivary Gland Tumors - Sinister Swellings

• Malignant features: Rapid growth, pain, facial nerve (CN VII) palsy, firm/fixed mass.
• Mucoepidermoid Carcinoma (MEC): Most common malignant. MAML2 translocation. Graded low to high.

  ⭐ Mucoepidermoid carcinoma is the most common malignant salivary gland tumor overall and also the most common in children.

• Adenoid Cystic Carcinoma (ACC): Perineural invasion (PNI) → pain. "Swiss cheese" (cribriform). MYB-NFIB. Relentless course.
• Acinic Cell Carcinoma: Parotid common. Good prognosis. Serous acinar cells.
• Carcinoma ex Pleomorphic Adenoma: Malignancy in pre-existing PA. Aggressive.
• Polymorphous Adenocarcinoma (PAC): Minor salivary glands. Indolent. PRKD1 mutations.
• Salivary Duct Carcinoma: Aggressive. Resembles breast ductal CA. Often Androgen Receptor (AR)+.

Salivary Gland Tumors - Gland Wars Chart

Salivary Gland Tumors - Tumor Takedown Tactics

• Initial Workup: Detailed history, thorough clinical examination (palpation, VII nerve status, cervical nodes).
• Imaging: Ultrasound often first; CT/MRI for deep extension, bone/nerve involvement, staging.
• Diagnostic Biopsy:

  ⭐ Fine Needle Aspiration Cytology (FNAC) is the crucial initial diagnostic investigation of choice for most salivary gland swellings, guiding further management.

• Treatment Principles:
  • Benign: Complete surgical excision (e.g., superficial/total parotidectomy, gland excision). Facial nerve preservation is paramount.
  • Malignant: Multimodal approach. Wide surgical resection, often with neck dissection. Post-op radiotherapy common. Nerve sacrifice if involved by tumor for cure.

High‑Yield Points - ⚡ Biggest Takeaways

• Pleomorphic adenoma: Most common overall salivary tumor, predominantly benign.
• Mucoepidermoid carcinoma: Most common malignant salivary tumor.
• Parotid gland: Most common location for salivary tumors (80%).
• Warthin's tumor: Second most common benign parotid tumor; strong smoker association, often bilateral.
• Adenoid cystic carcinoma: Characterized by perineural invasion and high recurrence rates.
• Facial nerve involvement in a parotid mass strongly indicates malignancy.
• Frey's syndrome (gustatory sweating) is a key complication post-parotidectomy.