| Invasive lobular carcinoma | |
|---|---|
 | |
| Lobules of the mammary glands. | |
| Specialty | Oncology |
Invasive lobular carcinoma (ILC) is breast cancer arising from the lobules of the mammary glands. It accounts for 5–10% of invasive breast cancer. Rare cases of this carcinoma have been diagnosed in men (see male breast cancer).
Types
| Classic lobular | Pleomorphic lobular | |
|---|---|---|
| Grades | Low or high (II/III) | High (III) |
| AJCC stage | I | II |
| Lymph node status | Negative | Positive |
| ER/PR status | Positive | Positive |
| Surgery type | Lumpectomy | Mastectomy |
The histologic patterns include:
| Type | Prevalence | Description | Image |
|---|---|---|---|
| Classical | 40% | Round or ovoid cells with little cytoplasm in a single-file infiltrating pattern, sometimes concentrically giving a targetoid pattern |
|
| Mixed | 40% | No dominant pattern | |
| Solid | 10% | Sheets of classical-appearing cells with little intervening stroma | |
| Alveolar | 5% | Aggregates of classical-appearing cells | |
| Tubulolobular | 5% | Cells form microtubules in >90% of tumor (smaller than in tubular carcinoma) | |
| Pleomorphic | Classical-appearing but with pleomorphic cells. It may include signet-ring cells, or plasmacytoid cells (pictured) which have abundant cytoplasm and eccentric nuclei. |
 |
Histopathology of invasive lobular carcinoma (ILC), next to lobular carcinoma in situ (LCIS)
Invasive lobular carcinoma demonstrating a predominantly lobular growth pattern
Lobular breast cancer. Single file cells and cell nests.
Prognosis
Overall, the five-year survival rate of invasive lobular carcinoma was approximately 85% in 2003.
Diagnosis
On mammography, ILC shows spiculated mass with ill-defined margins that has similar or lower density than surrounding breast tissues. This happens only at 44–65% of the time. Architectural distortion on surrounding breast tissues is only seen in 10–34% of the cases. It can be reported as benign in 8–16% of the mammography cases.
Ultrasound has 68–98% sensitivity of detecting ILC. ILC shows irregular or angular mass with hypoechoic or heterogenous internal echoes, ill-defined or spiculated margins, and posterior acoustic shadowin.
Loss of E-cadherin is common in lobular carcinoma but is also seen in other breast cancers.
Treatment
Treatment includes surgery and adjuvant therapy.