Final answer:
The term for a malignant neoplasm without tissue invasion is 'carcinoma in situ', a non-invasive condition that could develop into invasive cancer if not managed.
Step-by-step explanation:
The term that defines a malignant neoplasm site as the absence of invasion of surrounding tissues is carcinoma in situ. This stage is a part of pre-malignancy, where the neoplasm has not yet become an invasive tumor, which means the cancer cells have not started to invade the neighboring tissues. These non-invasive tumors, including atypia, dysplasia, and carcinoma in situ, can potentially progress to cancer if left untreated.