Microscopy of a minor salivary gland in Sjögren’s syndrome (SS): ‘periductal lymphoid focus’. The finding of at least 1 focus (periductal aggregate of at least 50 lymphocytes, mostly CD4+) in 4 mm2 of tissue is diagnostic for SS. The ‘score’ is the number of foci in 4 mm2 of tissue.
Tincani et al. BMC Medicine 2013 11:93 doi:10.1186/1741-7015-11-93