What is the histology of lacrimal duct epithelium?

• A. Ducts lined by simple squamous epithelium
• B. Ducts lined by simple cuboidal to columnar epithelium; larger ducts can be stratified
• C. Ducts lined by stratified squamous epithelium
• D. Ducts lined by pseudostratified ciliated epithelium

Answer: (B)

Duct epithelium changes with duct size. In the lacrimal gland's ducts, the lining starts as simple cuboidal and becomes taller as the ducts enlarge, transitioning toward simple columnar; in the largest ducts the lining can be stratified. This progressive change fits how many exocrine gland ducts behave, where small ducts are simple and larger ducts may be stratified.

So describing the ducts as lined by simple cuboidal to columnar epithelium, with stratification possible in the larger ducts, best matches the histology. The other options imply epithelial forms (pseudostratified ciliated, stratified squamous, or simple squamous) that aren’t typical for lacrimal duct lining.