Acinic Cell Carcinoma

Common sites:

• Most parotid
• Some in submandibular
• Rarely minor glands

Gross features:

• Small
• Discrete, may appear encapsulated
• Sometimes multicentric
• Sometimes bilateral

Histologic features:

• At least some cells resembling normal serous acinar cells of salivary glands
• Basophilic to slightly vesicular, eccentric nuclei
• Abundant, pale basophilic cytoplasm, often finely reticular, with purplish cytoplasmic granules
• variable architecture and cell morphology
• mixture of acinar, intercalated ductal, vacuolated, clear, and nonspecific glandular cells
• sheets / solid, or microcystic, glandular, follicular, or papillary patterns
• characteristically cleared cytoplasm, but sometimes solid or vacuolated
• usually little anaplasia
• usually few mitoses

Immunophenotype:

Marker:	Sensitivity:	Specificity:
PASD (granules in cytoplasm)
Mucicarmine (neg)
Amylase	Frequently weak or absent
Transferrin	Maybe
Lactoferrin	Maybe
CEA	Maybe
VIP	Maybe
S100 (some positivity)	10%

• staining unpredictable and is of little value in diagnosis

Molecular features:

Other features: