What is a characteristic of poorly differentiated tumors?

Poorly differentiated tumors exhibit high histological variability, which means that the cells within these tumors show significant differences in appearance compared to normal tissue. This variability can be attributed to the tumor's lack of differentiation, where the cancerous cells do not develop specialized features that are characteristic of the tissue of origin. This can make it difficult to identify the tumor's cell type based solely on its histological characteristics.

The high level of variability in poorly differentiated tumors is an indicator of their aggressive nature and often correlates with a poor prognosis. These tumors tend to exhibit more abnormal characteristics, including irregular shapes and sizes of cells, and a disorganized growth pattern. This contrasts with well-differentiated tumors, which maintain more normal cellular structures and closely resemble the surrounding healthy tissue.

The other characteristics mentioned typically apply to well-differentiated tumors or benign lesions, which tend to have defined borders, grow more slowly, and often do not metastasize. Such traits highlight the significance of understanding tumor differentiation in pathology, as it informs both diagnosis and potential treatment strategies.