Metastatic adenocarcinoma

MyPathologyReport
December 5, 2023

Metastatic adenocarcinoma refers to cancer that has spread from its original (primary) site to other parts of the body. The term adenocarcinoma specifically refers to a type of cancer made up of glandular cells, which are the cells found inside most internal organs. For example, if someone has metastatic adenocarcinoma of the breast, it means that cancer cells from the original breast tumor have spread to other organs or tissues in the body.

Cancer cells can break away from the primary tumor and travel through the bloodstream or lymphatic system to distant organs or tissues, where they can form new tumors. The new tumors are called metastases. Pathologists use the terms lymphovascular invasion and angiolymphatic invasion to describe cancer cells inside of a blood vessel or lymphatic space.

How do pathologists identify the original (primary) tumor?

Identifying the primary tumor in cases of metastatic adenocarcinoma can be challenging, but pathologists use a combination of techniques and tests to determine the origin of the cancer.

Here are some common methods:

• Histopathology: Pathologists examine the morphology (structure and appearance) of the cancer cells under a microscope. Adenocarcinomas arising in different parts of the body have distinct cellular features, and these features can provide clues about the origin of the tumor.
• Immunohistochemistry (IHC): Immunohistochemistry involves using antibodies that react with specific proteins present in different types of cells. By applying these antibodies to the tissue sample, pathologists can identify the presence or absence of certain proteins, helping to narrow down the possible origin of the cancer.
• Molecular and genetic tests: Advances in molecular and genetic testing allow pathologists to analyze the DNA, RNA, and protein expression patterns in cancer cells. Molecular profiling can provide information about the genetic mutations or alterations that are characteristic of certain types of cancer. These tests include next-generation sequencing (NGS), fluorescence in situ hybridization (FISH), and polymerase chain reaction (PCR).
• Clinical history and imaging studies: The patient’s clinical history, including symptoms, prior medical conditions, and imaging studies, can provide important context. Imaging studies, such as CT scans, MRIs, and PET scans, can help identify the location and extent of metastases and the original (primary) site of origin.

Despite these methods, determining the primary tumor site may not always be straightforward, especially in cases where metastasis is the first manifestation of cancer. In some instances, the primary tumor remains unidentified, and the cancer is classified as a “cancer of unknown primary” (CUP).

How is metastatic adenocarcinoma treated?

The prognosis and treatment options for metastatic adenocarcinoma depend on various factors, including the specific type of adenocarcinoma, the organs involved, and the overall health of the individual. Treatment may involve a combination of surgery, chemotherapy, radiation therapy, targeted therapy, immunotherapy, or other approaches, depending on the characteristics of the cancer and its extent of spread.

About this article

Doctors wrote this article to assist you in reading and comprehending your pathology report. Feel free to reach out to us with any questions about this article or your pathology report. To get a comprehensive introduction to your pathology report, read this article.

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