Which finding indicates invasion into stromal tissues on histology?

Which finding indicates invasion into stromal tissues on histology?

• A. Invasion into stromal tissues
• B. Metastasis to lymph nodes
• C. Distant metastasis
• D. In situ carcinoma

Answer: (A)

Invasion on histology is shown when tumor cells cross the basement membrane and penetrate the surrounding connective tissue (the stroma). This breach indicates the cancer has acquired the ability to infiltrate beyond the original epithelial layer, which is what marks it as invasive disease. If tumor cells stay confined above the basement membrane within the epithelium, that’s in situ carcinoma. Metastasis to lymph nodes or distant sites reflects spread of cancer cells beyond the primary site, but these findings describe metastasis rather than the histologic indication of invasion at the primary lesion. So, invasion into stromal tissues directly demonstrates that invasive behavior.

Invasion on histology is shown when tumor cells cross the basement membrane and penetrate the surrounding connective tissue (the stroma). This breach indicates the cancer has acquired the ability to infiltrate beyond the original epithelial layer, which is what marks it as invasive disease. If tumor cells stay confined above the basement membrane within the epithelium, that’s in situ carcinoma. Metastasis to lymph nodes or distant sites reflects spread of cancer cells beyond the primary site, but these findings describe metastasis rather than the histologic indication of invasion at the primary lesion. So, invasion into stromal tissues directly demonstrates that invasive behavior.