Which of the following are considered malignant?

The question focuses on identifying which tumors are considered malignant. Among the options provided, gliomas and lymphomas are classified as malignant tumors, but the specific answer highlights gliomas.

A glioma is a type of tumor that occurs in the brain and spinal cord and arises from glial cells, which support and protect the neurons. These tumors can be aggressive and invasive, often leading to serious health consequences due to their location and growth patterns. Their malignant nature is characterized by uncontrolled cell proliferation and the potential to spread within the central nervous system.

Lymphomas, although not indicated as the correct answer in this case, are also malignant tumors originating from lymphatic tissue. However, gliomas hold a specific place in the context of cancer given their critical impact on neurologic function.

In contrast, lipomas and osteomas are benign tumors. Lipomas consist of fatty tissue and typically do not pose a risk of metastasis or aggressive behavior. Osteomas are benign bone tumors, primarily found on the skull or facial bones, and also lack malignant potential. The distinction between malignant and benign tumors is vital in understanding their behavior, treatment options, and implications for patient health.