A malignant mesenchymal neoplasm arising from adipocytes. The disease is lipomatous cancer (Monarch Disease Ontology id MONDO_0002813). Also known as: adipose tissue cancer, cancer of adipose tissue, malignant adipose tissue neoplasm, malignant adipose tissue tumor, malignant adipose tissue tumour, malignant lipomatous neoplasm, malignant lipomatous tumor, malignant lipomatous tumour.