Characterization of lacrimal sac histology: an immunohistochemical study.

Background: A prospective observational study in a university hospital setting to study the immunohistochemical (IHC) characteristics of non-neoplastic human lacrimal sac epithelium.

Methods: Twenty paraffin-embedded specimens of human lacrimal sac were studied using monospecific monoclonal antibodies to 34 beta E12, cell adhesion molecule (CAM 5.2), epithelial membrane antigen (EMA), cytokeratins (CK) 7 and 20, estrogen receptor and progesterone receptor. The distribution and histologic location of IHC staining were examined qualitatively, and the IHC stains scored as positive (+) or negative (-).

Results: The haematoxylin-eosin stains were reviewed for tissue morphology. All 20 specimens were positive for 34 beta E12, CAM 5.2, EMA and CK 7 and negative for CK 20, estrogen receptor and progesterone receptor.

Conclusion: To our knowledge, this is the first study to characterize the IHC properties of human lacrimal sac epithelium. This epithelium appears to possess consistent IHC properties as it stains for 34 beta E12, CAM 5.2, EMA and CK 7 and this information would be potentially useful in differentiating tumours arising in the region of the lacrimal sac.