--- title: "Pleomorphic Adenoma" description: "ENT notes on Pleomorphic Adenoma - Histogenesis, Histology, Symptoms, Investigations, Treatment and Recurrence." source: "The ENT Resident" author: "Dr. Mausumi Das" canonical_url: "https://www.theentresident.com/ent-notes-lectures/pleomorphic-adenoma-histology-treatment" categories: ["Oral Cavity and Salivary Glands"] video: "https://www.youtube.com/watch?v=44L7F9XpVxc" image: "https://media.theentresident.com/og-images/pleomorphic-adenoma-histology-treatment.png" --- # Pleomorphic Adenoma ENT notes on Pleomorphic Adenoma - Histogenesis, Histology, Symptoms, Investigations, Treatment and Recurrence. Watch the full video lecture on YouTube: https://www.youtube.com/watch?v=44L7F9XpVxc ## 🧬 Pleomorphic Adenoma ### 📌 Definition of Pleomorphic Adenoma **Pleomorphic adenoma** is a **biphasic (mixed) tumour** composed of **epithelial** and **mesenchyme like** (stromal) elements forming a variable myxoid, chondroid, osseous or adipose stroma. >What features make pleomorphic adenoma "pleomorphic"? >Which cell types form the epithelial component? >Which is the most common benign salivary gland tumour? >What is the most common site of pleomorphic adenoma? - **Age / Sex:** 4th–6th decade (peak ~6th decade); **female preponderance**. - **Malignant transformation** (Carcinoma ex-pleomorphic adenoma) risk ≈ **1–5%** after long duration (~≥10 years). --- ### 🔬 Histogenesis of Pleomorphic Adenoma 1. **Dardick’s Theory** - Origin from **intercalated duct reserve cells** (pluripotent epithelial progenitors). - Myoepithelial cells → undergo **mesenchymal metaplasia** → produce myxoid / chondroid / osseous / adipose stromal elements. - Implies **purely epithelial origin** with stromal elements being myoepithelial derived (mesenchyme like, not true mesenchyme). 2. **Willis’ Theory** - Tumour arises from **both epithelial and mesenchymal elements** → true mixed tumour (stromal elements are true mesenchyme). 3. **Genetic Evidence** - Chromosomal rearrangements reported (e.g., **8q12 PLAG1**, **12q13-15 HMGA** family) - support a clonal epithelial origin with myoepithelial plasticity. --- ### 🗺️ Sites & Epidemiology of Pleomorphic Adenoma - **Parotid** — ≈85% (superficial lobe ~80% of parotid cases; deep lobe ~10%). - **Submandibular** — ≈8% of pleomorphic adenomas. - **Minor salivary glands** — ≈7% (palate commonest). --- ### 🧾 Gross Pathology of Pleomorphic Adenoma - **Appearance:** Irregular–ovoid, well-circumscribed mass; cut surface fleshy, rubbery or glistening, tan-white. - **Capsule:** Thin fibrous capsule (may be incomplete); minor gland lesions often unencapsulated. - **Pseudopodia:** Tumour projections into adjacent gland (pseudopods) — important cause of recurrence if incompletely excised. - **Areas of haemorrhage/infarction** may be seen. --- ### 🔬 Microscopy of Pleomorphic Adenoma **Epithelial component** - **Ductal structures**: cuboidal/columnar/oncocytic lining. - **Solid nests, sheets, cords, trabeculae** may be present. **Myoepithelial component** - Highly variable: **spindle**, **plasmacytoid (plasmacytoid/epithelioid)**, **clear** cell forms. - **Myoepithelial cells** are key to stromal diversity. **Stromal / Mesenchyme-like component** - **Myxoid** (most common), **chondroid**, **osseous**, **adipose** — degree/type of stroma determines tumour firmness. >🚩 Presence of cartilage/bone or calcification in a salivary mass is suggestive of pleomorphic adenoma. --- ### 🩺 Clinical Features of Pleomorphic Adenoma - **Presentation:** Single, slow-growing, **painless**, smooth, lobulated, mobile swelling - classically **just below and in front of the ear** (parotid region). - Positive curtain sign - **Ear lobule elevation** may be seen with superficial parotid tumours. - **Deep lobe lesions:** present as **intraoral / parapharyngeal** swelling (medial displacement of tonsil / oropharyngeal wall) → dysphagia, stertor, voice change. - **Facial nerve involvement** is rare in benign pleomorphic adenoma - if present suspect malignancy. >What is Positive curtain sign? --- ### 🚩 Red Flags for Carcinoma ex Pleomorphic Adenoma - Recent rapid increase in size - Pain - Fixity to skin / deep structures - Ulceration / skin infiltration - Facial nerve palsy - Nodularity / irregularity - Regional lymphadenopathy - Restricted jaw movement --- ### 🧪 Investigations of Pleomorphic Adenoma 1. **Ultrasound** 2. **FNAC** (Fine Needle Aspiration Cytology) 3. **MRI** - Gold standard for soft tissue 4. **CT** - helpful for bony detail or if MRI contraindicated. 5. **Core biopsy** - generally **avoided** (risk of seeding, facial nerve injury); reserved if FNAC inconclusive and results will change management. 6. **Scintigraphy (Tc-99m pertechnetate)** — not routine for pleomorphic adenoma (more useful for Warthin’s tumour). >What is the first line imaging done in Pleomorphic Adenoma? >What are the indications of MRI in Pleomorphic Adenoma? --- ### 🛠 Treatment of Pleomorphic Adenoma - **Surgery is the treatment of choice** - **No role for radiotherapy/chemotherapy** in primary benign disease. 1️⃣ **Parotid** - **Enucleation** → **obsolete** (high recurrence due to thin capsule and pseudopodia). - **Superficial parotidectomy** (remove superficial lobe + tumour, **preserve facial nerve**) - standard for superficial lobe tumours. - **Total conservative parotidectomy** (both lobes removed, **facial nerve preserved**) - indicated for deep lobe involvement or multicompartment disease / tumour spillage. - **Extracapsular dissection** - limited excision outside the capsule + small rim of normal tissue. - **Parapharyngeal / deep lesions** — cervico-parotid approach; very large / difficult lesions may require transmandibulotomy or transpharyngeal approaches. >What are the indications of Extracapsular dissection in Pleomorphic Adenoma? 2️⃣ **Submandibular gland** - **Complete excision of the gland** with tumour (preserve lingual, hypoglossal, marginal mandibular nerves). Do not perform partial gland excision. 3️⃣ **Sublingual gland** - **Excision via intraoral approach** (gland + tumour). 4️⃣ **Minor salivary glands** - **Wide local excision** with cuff of normal mucosa/periosteum (palatal tumours excised to periosteum) and reconstruction as needed. --- ### 🔁 Recurrence & Follow-Up of Pleomorphic Adenoma - **Recurrence rate** after superficial parotidectomy ≈ **2–5%**, often occurring **~10 years** after primary surgery. - **Recurrent tumours** are often **multicentric** and carry a higher risk of malignant transformation (≈3–6%). - **Management of recurrence:** **Total parotidectomy** with facial nerve preservation when possible; consider **post-op radiotherapy** in selected recurrent/incompletely resectable cases. - **Submandibular recurrence** → treat with selective neck dissection (levels I–III) if indicated. >What are the causes of recurrence of Pleomorphic Adenoma? >What is the Imaging for recurrence for Pleomorphic Adenoma? --- ### 🩺 Prognosis of Pleomorphic Adenoma - **Excellent** if completely excised with clear margins and intact capsule. - Long-term follow-up required due to late recurrences and small risk of malignant transformation. --- ## About This Note This free ENT note on Pleomorphic Adenoma was written by Dr. Mausumi Das and is paired with a corresponding video lecture. 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