The focus score is a semiquantitative method to assign a probabilistic risk category for patients undergoing evaluation for Sjogren's syndrome.
Some basic rules for interpretation apply:

• Minimum adequacy should be at least 4 lobules and at a minimum, 8 mm^2 of acinar surface area (EULAR recommendatin)
• One should only score minor salivary lobules without pre-existing chronic or fibrosing injury
• Do not score lobules with pre-existing atrophic or fibrotic changes (look for dilated ducts with periductal fibrosis)
• A significant focus is one with greater than 50 lymphocytes (+/- minor plasma cell component) around a duct or acinus. Foci with few sparse cells or uniformly plasma cell infiltrates don't count
• Try to keep the entire patches of inflammatory foci as one focus
• In florid cases, it can be hard to separate one focus from another. Some recommendations include counting entire lobules as a focus and this finding can be qualified in a comment

Normal salivary lobule

Focal lymphocytic sialadenitis

Non-specific chronic sialadenitis lobule

Sclerosing chronic sialadenitis