A cancerous tumor of the glandular tissue is classified as which of the following?

A cancerous tumor originating from glandular tissue is specifically classified as adenocarcinoma. This type of carcinoma arises from epithelial cells that have secretory properties, which are commonly found in glandular tissues such as those in the breast, prostate, pancreas, and others. Adenocarcinomas are characterized by their structure and origin, which differentiates them from other types of cancer.

While carcinoma is a broader term that includes all types of cancers arising from epithelial cells, adenocarcinoma specifically refers to those that exhibit glandular differentiation. Sarcoma refers to cancers originating from connective tissues such as bone, muscle, or fat. Melanoma is a type of cancer that typically arises from melanocytes, which are the pigment-producing cells of the skin. Thus, the specificity of adenocarcinoma as it relates to glandular tissue makes it the correct classification for the tumor described.