Los Angeles Society Of Pathologists Dr. Shobha Castelino Prabhu Loma Linda University Medical Center June 12, 2007
CASE 1 76 year-old gentleman Status post right parotidectomy 1 year ago for a rare tumor Presents with a right 5 cm pre-auricular and a 3 cm post-auricular mass - both are firm and immobile Right facial nerve partial paralysis with tingling sensations Fine needle aspiration was performed Followed by excision of both masses
FNA
FNA CYTOLOGY Biphasic cell population around tubule-like structures: inner small dark cells outer large pale cells Dense refractile ground substance within tubules Acellular myxoid/hyaline material present
Excision Multinodular growth Well circumscribed
DIAGNOSIS Recurrent epithelial-myoepithelial carcinoma of the parotid gland, intermediate grade
CASE 2 71 year-old lady awaiting renal transplant Found to have an irregular spiculated soft tissue density in the left upper lung CT guided needle core biopsy followed by left lung resection
Touch prep
Cytokeratin cocktail
S100
GFAP
S100
DIAGNOSIS Epithelial-myoepithelial carcinoma of salivary gland type, arising in the lung
CASE 3 57 year-old gentleman History of radiation for lung cancer, 2003 Now with large heterogenous liver mass CT guided liver biopsy was performed
Touch prep
Liver biopsy
H&E SMA CK7 CK20
DIAGNOSIS Metastatic carcinoma consistent with epithelial-myoepithelial carcinoma
REVIEW OF NORMAL SALIVARY GLAND ANATOMY AND HISTOLOGY Major salivary glands: 3 pairs of exocrine secretory glands Minor salivary glands: numerous (up to 1000), unencapsulated, distributed throughout mouth, oropharynx, upper respiratory, sinonasal and paranasal tracts Function: production and secretion of saliva Functional unit: tubuloacinar gland = secretory acinus (sero-mucinous) + duct + myoepithelial cells
Atlas of Tumor Pathology- AFIP Atlas of Tumor Pathology- AFIP WHO classification of tumours
Mac DeMay, Practical Princ.of Cytopathology
AFIP classification of salivary gland tumors, third series fascicle MALIGNANT EPITHELIAL NEOPLASMS BENIGN EPITHELIAL NEOPLASMS Mucoepidermoid carcinoma Adenocarcinoma Acinic cell adenocarcinoma Adenoid cystic carcinoma Polymorphous low-grade adenocarcinoma Malignant mixed tumor Carcinoma ex mixed tumor Carcinosarcoma Metastasizing mixed tumor Squamous cell carcinoma Basal cell adenocarcinoma Epithelial-myoepithelial carcinoma Clear cell adenocarcinoma Cystadenocarcinoma Undifferentiated carcinomas Small cell, large cell, lymphoepithelial Oncocytic carcinoma Salivary duct carcinoma Sebaceous adenocarcinoma & lymphadenocarcinoma Myoepithelial carcinoma Adenosquamous carcinoma Mucinous adenocarcinoma Mixed tumor (pleomorphic adenoma) Myoepithelioma Warthin s tumor Basal cell adenoma Canalicular adenoma Oncocytoma Cystadenoma Ductal papillomas Lymphadenomas, sebaceous adenomas Sialoblastoma MESENCHYMAL NEOPLASMS Benign Malignant MALIGNANT LYMPHOMAS METASTATIC TUMORS NON-NEOPLASTIC TUMOR-LIKE CONDITIONS
EPITHELIAL MYOEPITHELIAL CARCINOMA Uncommon (~1%), mainly parotid, primarily in adults (6 th -7 th decade) Female > male Clinically: swelling, pain, facial weakness (palsy) Gross: well-circumscribed, firm Micro: biphasic, PAS + material in lumen & cytoplasm (glycogen), <2 mitoses per hpf
EPITHELIAL MYOEPITHELIAL CARCINOMA Immunostains: ductal cells are CK, EMA + clear cells are S100, SMA, HHF35, GFAP, p63, calponin + EM: electron dense epithelial cells surrounded by electron lucent myoepithelial cells Behavior: low grade malignancy 40% recurrence 14% metastasize (periparotid and cervical nodes, lung, liver, kidney) Margin status Poor prognosis- minor salivary gland tumors, atypia (>20%), dedifferentiation, aneuploidy Treatment: surgical excision +/- radiation
DIFFERENTIAL DAGNOSIS Biphasic Tumors : Pleomorphic adenoma Adenoid cystic CA PLGA Clear Cell Tumors : Clear cell carcinoma, NOS Mucoepidermoid CA Acinic cell CA Sebaceous CA Oncocytoma Metastatic renal cell, thyroid CA
Pleomorphic Adenoma/ Benign Mixed Tumor Bland epithelial cells, and fibrillar, metachromatically staining stroma ( troll s hair ) www. pathology2.jhu.edu epithelial & mesenchymal cells, chondromyxoid stroma Commonest salivary gland tumor Follows the rule of 80 s 25% recur if enucleated www.ym.edu.tw/pat
Adenoid cystic carcinoma 2 nd most common malignant parotid tumor,? commonest malignant minor salivary gland tumor (palate) Cytology- 3D tight rings surrounding hyaline globules of basement membrane-like material, few bare nuclei/ large myoepithelial cells in background www.pathology.uth.tmc.edu Cribriform patternpseudoglandular spaces filled with cylinders of PAS+ material Loves nerves!!! Lung metastases CD117 positive Silverberg s Prin.&Pract. Of Surg. Path Rosai and Ackerman s Surg.Path.
SUMMARY Rare, low grade carcinoma Usually arising in the parotid gland Three cases of EMC One typical location (parotid) Two apparently primary in the lung one metastatic to liver Important to distinguish from: pleomorphic adenoma because of its potential for metastasis adenoid cystic carcinoma because of its less aggressive nature
REFERENCES Atlas of Tumor Pathology (Tumors of the Salivary Glands)- AFIP WHO classification of tumours- Head and Neck tumours Elsevier Inc 2004 Rosai and Ackerman s Surgical Pathology 9 th ed. Sternberg's Diagnostic Surgical Pathology 4 th ed. Silverberg's Principles and Practice of Surgical Pathology and Cytopathology Pathologic Basis of Disease, 7 th ed., Robbins and Cotran
Special thanks Dr. Craig Zuppan Dr. Anwar Sultana Raza Dr. Wesley Stevens Dr. Jeff Cao Dr. Daniel Buxton Dr. Mingyi Chen Loma Linda Histology