1. Adenoid Cystic Carcinoma(AdCC)
cylindroma

2. one of the more common salivary gland malignancies (MEC / PLGA / AdCC)
A high grade malignancy
Because of its distinctive histopathologic features, it was originally called
a cylindroma

4. Histopathologic Features
composed of a mixture of myoepithelial cells and ductal cells that can have a varied arrangement
Three major patterns:
Cribriform
Tubular
solid
Usually a combination of these is seen

5. The cribriform pattern is the most classice
characterized by islands of basaloid epithelial cells
that contain multiple cylindric, cystlike spaces resembling Swiss cheese
homogeneous acidophilic material
cystlike spaces often contain a mildly basophilic mucoid material, a
hyalinized eosinophilic product, or a combined mucoid hyalinized
appearance.

6. Cribriform (Swiss cheese)
small and cuboidal, cells
deeply basophilic nuclei
little cytoplasm
fairly uniform
Rare mitotic activity

7. Normal salivary glands Adjacent with tumor

8. Cribriform
pattern

9. tubular pattern
occur as multiple small ducts or tubules within a hyalinized
stroma
The tubular lumina can be lined by one to several layers of cells
(ductal cells and myoepithelial cells)

10. tubular pattern

11. hyalinized "stroma

12. solid variant
consists of larger islands or sheets of tumor cells
little tendency toward duct or cyst formation

13. Solid
Cribriform
small and cuboidal, cells
deeply basophilic nuclei
little cytoplasm
fairly uniform
cellular pleomorphism and
mitotic activity

14. as well as focal necrosis in the center of the tumor islands, may be observed

15. A highly characteristic but no pathognomonic perineural invasion
a swirling arrangement around
nerve bundles
which probably corresponds to the common clinical finding of pain in these patients
This marked tendency to proliferate around and along nerves for great distances accounts for the tumor's marked tendency to recur.

16. Tumors with a solid histopathologic pattern are associated with a worse outlook
the prognosis is poorest for tumors arising in the maxillary
sinus and submandibular gland.
The end