What Do Signet Ring Cells Mean in Stomach Cancer?

Seeing the term “signet ring cells” on a biopsy report can be overwhelming. While it indicates a serious and specific type of cancer that requires a tailored approach, the name itself simply comes from how the cells look under a microscope.

Signet ring cells are cancer cells that have filled up with a large amount of mucus (mucin). This pool of mucin pushes the cell’s nucleus—its control center—to the very edge of the cell membrane. Under a microscope, this creates a distinct appearance that looks exactly like a classic jeweler’s “signet ring” ^[1][2].

The Hallmark of Diffuse Gastric Cancer

Signet ring cells are the classic, defining feature of diffuse gastric cancer. Their presence provides your care team with important clues about how the cancer is likely to behave.

Most typical cancers grow by clumping together to form a solid, distinct tumor mass. Signet ring cells, however, do not stick together. Instead, they tend to break apart and spread widely, infiltrating the deeper layers of the stomach tissue ^[2][3][4].

Because they scatter and weave through the stomach wall horizontally and deeply, they can sometimes cause the stomach muscle to become thick, stiff, and rigid rather than forming a single visible lump ^[2]. You might see this stiffening referred to in your medical records as linitis plastica ^[2]. Because they spread out rather than forming a lump, these cells can also sometimes be harder to spot early on standard scans or endoscopies.

How Signet Ring Cells Impact Your Treatment Plan

Knowing that your tumor contains signet ring cells is incredibly valuable for your oncology team because it directly influences your treatment strategy.

Because of their unique biology, signet ring cells do not always respond to traditional chemotherapy in the same way as other types of stomach cancer ^[5]. For many gastric cancers, the standard of care is a powerful chemotherapy regimen called FLOT (a combination of four different drugs) given before and after surgery ^[6][7].

However, research shows that signet ring cells can sometimes be less sensitive or more resistant to standard perioperative chemotherapy (chemo given around the time of surgery) ^[5]. Because of this nuance, your doctors will carefully customize your treatment plan. Depending on the stage of the cancer and how deeply it has spread, your team will weigh whether to start with FLOT chemotherapy to target microscopic cancer cells, or if proceeding straight to upfront surgery—which often means a partial or total removal of the stomach (gastrectomy)—is a safer, more effective first step for your specific situation ^[8][9].

If your cancer is resistant to standard chemotherapy, your doctors may also explore other options, such as incorporating immunotherapy, targeted therapies, or clinical trials that are actively investigating new ways to treat this specific cell type ^[10][11][12].

Finally, because some cases of diffuse gastric cancer with signet ring cells are linked to an inherited genetic mutation (such as in the CDH1 gene), your doctor may recommend genetic testing ^[13]. This is important not just for guiding your treatment, but also for identifying if blood relatives (like your children or siblings) might carry the same gene and need proactive screening.

By identifying these cells early, your doctors can avoid a one-size-fits-all approach and choose a highly personalized treatment plan tailored to your exact diagnosis.