eng Oriental Scientific Publishing Company Biomedical and Pharmacology Journal 0974-6242 2022-09-29 15 3 1671 1676 10.13005/bpj/2505 45835 article Ni Wayan Armerinayanti 1 Samuel Widodo 1 Desak Putu Oki Lestari 1 Department of Anatomic Pathology, Faculty of Medicine and Health Sciences Warmadewa University, Denpasar, Indonesia. Papillary thyroid carcinoma (PTC) comprises 80% of well-differentiated thyroid carcinomas. PTC progression is determined by a variety of biological markers, some of which are connected to the activities of Tumor-Associated Macrophage (TAM). TAM activity is difficult to observe using simply traditional histology techniques. Matrix Metalloproteinase 9 (MMP-9) is an important marker for identifying the development of PTC. However, no studies have linked the expression of MMP-9 to intratumoral macrophages in PTC patients, demonstrating that these macrophages are TAMs implicated in the development of PTC. Through MMP-9 expression on intratumor macrophages, the objective of this work was to evaluate TAM's involvement as a progression determinant of PTC. This cross-sectional study analyzed 40 samples, which included 21 PTC patients with intratumor macrophages and 19 PTC instances without intratumor macrophages. Medical records and paraffin blocks of the Biomedical Laboratory, Faculty of Medicine and Healthcare, Warmadewa University were used to collect samples. The proportion of MMP-9 expression in both groups' macrophages was then determined by immunohistochemical labeling and evaluated using Chi-Square with a significance level (a) of . The results revealed a statistically significant difference in MMP-9 expression between the PTC groups with and without intratumor macrophages, with p-value = 0.001  and OR = 11.9. https://biomedpharmajournal.org/vol15no3/matrix-metalloproteinase-9-expression-by-immunohistochemistry-in-intratumor-macrophages-as-tumor-associated-macrophage-marker-of-papillary-thyroid-carcinoma/ Histopathology Immunohistochemistry Staining Intratumor Macrophages Matrix Metalloproteinase 9 Papillary Thyroid Carcinoma Tumor-Associated Macrophage