Background and Objectives : Both the granulation tissue and cholesterol granuloma can erode the surrounding bone and ossicles. However, the etiology of bone resorption in the granulation tissue and cholesterol granuloma has not been evident. The
aim of
this study was to assay the concentrations of arachidonic acid metabolites (AAMs) in cholesterol granuloma and the mastoid granulation tissue in order to better understand the possible role of AAMs in the pathophysiology of cholesterol granuloma
in
comparison with the granulation tissue. Materials and Method : Cholesterol granuloma tissues were obtained from eight patients who had underwent tympanomastoidectomy. Granulation tissues, which served for comparison, were taken from 12 patients
who
had
underwent tympanomastoidectomy. Tissue concentrations of prostagladin (PG)E2, 6-keto-PGF1α, leukotriene (LT)C4, LTD4, LTE4, 15-hydro xyeicosatetraenoic acid (HETE), 12-HETE, 5-HETE, and thromboxane (TXB)2 were calculated using high performance
liquid
chromatography and compared between cholesterol granuloma and granulation tissue. Result : The level of 12-HETE was higher in cholesterol granuloma than in the granulation tissue. Among the PGs, the tissue concentration of PGE2 was particularly
high in
cholesterol granuloma than in the granulation tissue. LTD4 was the only LT detectable in cholesterol granuloma. In comparison to the AAMs in cholesterol granuloma, the lipoxygenase pathway products such as 12-HETE, 15-HETE, and 5-HETE were
present
in
lower concentrations in the granulation tissue. LT was undetectable in the granulation tissues. Conclusion : Our results suggest that cholesterol granuloma and the granulation tissue is different not only in terms of histology, but also in terms
of
biochemical properties such as arachidonic acid metabolism.
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