You will be shown an abstract from a biomedical research paper. Given this abstract, your task is to extract all unique entities of the following types: ["AnatomicalEntity"].

Please return the output as a JSON object of the format: {"AnatomicalEntity": ["tumor cells", ...]}. The keys should be entity types and values should be lists of extracted entities belonging to the corresponding type. If you cannot find entities belonging to a specific type, the value should be [].

Only output the JSON object and do not include any additional text.

Abstract:

[Correlation between expression of vascular endothelial growth factor-C in tumor-associated macrophages and lymphatic metastasis in oral cancer]. 
BACKGROUND &#38; OBJECTIVE: Previous study shows that both vascular endothelial growth-C (VEGF-C) and tumor-associated macrophages (TAMs) are related to lymphatic metastasis. This study aimed to explore the correlation between the expression of VEGF-C in TAMs and lymphatic metastasis in human oral squamous-cell carcinoma (OSCC). METHODS: After immunohistochemical staining, light microscope was used for counting macrophages and automated image analysis quantification was used to determine VEGF-C expression,which was reflected by positive index (PI). In addition,the double staining was also used to determine VEGF-C expression in TAMs. RESULTS: VEGF-C expression was higher in lymphatic metastasis group (PI=12.169+/-2.778) than in no-metastasis group (PI=8.498+/-2.674, P< 0.05). TAMs counts was related to VEGF-C expression in OSCC (r=0.370, P< 0.05). The result of double staining indicated that macrophage with positive VEGF-C expression accounted for about 22.8% of the total. CONCLUSION: Not only tumor cells but also TAMs secrete the VEGF-C in OSCC, and TAMs may play a major role in peritumoral lymphatic neoangiogenesis and lymphatic metastasis.
{"AnatomicalEntity": ["OSCC", "tumor cells", "oral cancer", "macrophages", "macrophage", "lymphatic", "tumor-associated macrophages", "TAMs", "oral squamous-cell carcinoma", "peritumoral lymphatic"]}