Parotidectomy and histology images described individually.
Gross Pathology
Pleomorphic adenomas arising in the parotid gland usually have a pink-tan rubbery surface, well-defined pushing margins, and translucent areas of cartilaginous differentiation (as seen in this image). A rim of uninvolved salivary gland parenchyma is present around the tumor in this superficial parotidectomy specimen.
HE
- Pleomorphic adenomas often have a biphasic appearance caused by admixture of epithelium and stroma. The epithelial component here is arranged in tubular and glandular structures. The stroma has myxochondroid appearance
- Microscopically, the pleomorphic adenomas consist of three elements: epithelial cells, myoepithelial cells, and stroma. The epithelial cells commonly form tubular or glandular structures and are surrounded by myoepithelial cells. The background stroma may be myxoid, chondroid, hyalinized, or vascular
- Pleomorphic adenomas arising in the parotid usually have a thick fibrous capsule as seen here. The normal parotid tissue is to the upper right of the capsule and the tumor is on the lower left. The capsule can be variable in thickness and may even be absent. Pleomorphic adenomas arising in the minor salivary glands are well-demarcated but usually not encapsulated