Abstract
Objective Salivary gland diseases and their pathologies may affect the glandular structure
including collagen, a major stromal component, in response to tissue damage or diseases.
This study aimed to examine the changes in collagens in different salivary gland diseases
using polarized picrosirius red staining.
Materials and Methods The submandibular gland samples diagnosed as sialadenitis, chronic sclerosing sialadenitis,
pleomorphic adenoma, adenoid cystic carcinoma, and mucoepidermoid carcinoma were stained
with picrosirius red, Masson's trichrome, and anticollagen I staining. The quantity
of collagens was examined and reported as a percentage of positive picrosirius red
area. The maturity of collagens was studied with polarized light microscope and reported
as a percentage of orange-red and yellow-green polarized collagens, representing the
mature and immature collagens, respectively.
Statistical Analysis The % positive areas for picrosirius red representing the collagen amount among salivary
gland diseases were analyzed by one-way analysis of variance with Tukey's test. The
% orange-red and % yellow-green polarized areas representing the collagen maturity
were analyzed by Kruskal–Wallis test and Mann–Whitney U test.
Results The malignant tumors, adenoid cystic carcinoma (29.92) and mucoepidermoid carcinoma
(26.59), had higher significant percentage of positive picrosirius red area, compared
with the benign tumor (14.56), chronic sclerosing sialadenitis (10.61), and sialadenitis
(7.22) (p < 0.05). The percentages of orange-red polarized areas are 48.07, 39.6, 62.67, 83.75,
and 76.05 in sialadenitis, chronic sclerosing sialadenitis, pleomorphic adenoma, adenoid
cystic carcinoma, and mucoepidermoid carcinoma, respectively. This percentage tended
to increase in the benign and malignant lesions with statistical difference, compared
with the inflammatory lesions (p < 0.05). There was no statistical difference in the percentages of yellow-green polarized
areas among various salivary gland diseases. In addition, the results of Masson's
trichrome and anticollagen I staining are corresponding to that of picrosirius red
among various salivary gland diseases.
Conclusions Polarized picrosirius red demonstrated the most amounts of collagen in the malignant
lesion, and represented the different maturity of collagens in each lesion group.
Studying the amounts and maturity of collagen with picrosirius red for extracellular
matrix alteration in salivary gland diseases along with routine hematoxylin and eosin,
Masson's trichrome, and immunohistochemistry may provide a better understanding in
different salivary gland pathologies.
Keywords
salivary gland diseases - picrosirius red - polarized light - Masson's trichrome -
collagen
