What type of malignant tumors arise from mesenchymal (connective) tissue?

Sarcomas are the malignant tumors that originate from mesenchymal or connective tissue. This type encompasses a diverse group of tumors that can arise from various types of connective tissues, including bone, cartilage, fat, muscle, and vascular tissue. The defining characteristic of sarcomas is their derivation from mesodermal tissue, which is distinct from other tumor types.

In contrast, carcinomas are cancers that arise from epithelial cells, not mesenchymal tissue, and are often found in organs like the lungs, breast, and skin. Neurofibromas are benign tumors that develop from nerve tissue and specifically arise from Schwann cells, which are a type of mesenchymal cell but are classified differently in terms of malignant potential. Adenomas are benign tumors formed from glandular epithelium and are distinct from the malignant nature of sarcomas, as they do not arise from connective tissue.

Thus, the classification and origin of the tumors confirm that sarcomas specifically arise from mesenchymal tissue, making this the correct answer.