Breast cancer types4 min read

Invasive lobular carcinoma (ILC)

ILC starts in the milk-producing lobules and spreads through the breast in subtle, linear ways, which can make it harder to feel.

Invasive lobular carcinoma is the second most common invasive breast cancer. Its cells tend to spread in single-file lines rather than as a firm lump, so it may show up as thickening or a changed texture instead of a distinct mass.

What to know about ILC

  • About 10–15% of invasive breast cancers
  • Often hormone-receptor positive
  • Sometimes missed by touch — imaging matters
  • Bilateral imaging (both breasts) is often recommended

Because ILC can be subtle, both breasts are usually imaged at diagnosis. Treatment follows the same modern pathway as other invasive cancers.

In brief

The second most common invasive type
Grows in subtle single-file patterns
Usually hormone-receptor positive

What you can do

Insist on imaging

ILC can hide from fingers but not from machines.

Check both sides

Ask whether bilateral imaging is recommended for you.

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