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:

[Parotid gland's tumors in children].
The tumors of the salivary glands are infrequent in children, and parotid gland is involved in 80% of them. When a salivary gland tumor is present, the chance of malignancy is greater in the child than in the adult. We reviewed 8 cases identified in patients aged 14 years and younger in our hospital, analyzing its antecedents, signs and symptoms, histological features, diagnosis, treatment and evolution. All the patients displayed preauricular painless, non-inflammatory and slow-growing masses to an age between 10 months and 14 years. Four or them were pleomorphic adenomas, two haemangiomas, one epidermal cysts and one myoepithelial carcinoma. We emphasize the exceptional nature of the carcinoma for its rareness and for the high degree of malignancy expressed. We made a fine needle aspiration biopsy in four cases but they were conclusive only in three. All were treated by surgical resection of the tumour except for the myoepithelial carcinoma and the recurrent pleomorphic adenoma that were treated by total parotidectomy. The malignant tumours of the parotid gland are clinically indistinguishable of the benign ones, thus when any palpable mass appears in the zone of the parotid gland, an accurate diagnosis should be made without delay. The treatment of choice is the surgical excision with wide margins, being other adjuvant treatments less useful to this age than in the adult age.
{"AnatomicalEntity": ["preauricular", "epidermal cysts", "tumors", "tumour", "benign ones", "palpable mass", "haemangiomas", "malignant tumours", "Parotid gland\u0027s tumors", "pleomorphic adenomas", "carcinoma", "masses", "salivary glands", "pleomorphic adenoma", "myoepithelial carcinoma", "salivary gland tumor", "parotid gland"]}