Lobular carcinoma in situ

Diagram showing lobular carcinoma in situ (LCIS) CRUK 166

Lobular carcinoma in situ (LCIS) is a condition in which abnormal cells are found in the lobules of the breast. Despite its name, LCIS is not considered a true breast cancer, but rather a marker indicating an increased risk of developing breast cancer later in life. LCIS is often discovered incidentally during a biopsy for another reason, as it typically does not present with a palpable lump or show up on a mammogram.

Diagnosis[edit | edit source]

The diagnosis of LCIS is usually made following a biopsy of the breast tissue, often performed for unrelated reasons, as LCIS itself does not usually produce symptoms or abnormalities on imaging studies. Histologically, LCIS is characterized by a proliferation of small, uniform cells that fill and expand the lobular units of the breast. These cells typically exhibit minimal atypia and do not breach the basement membrane, distinguishing LCIS from invasive lobular carcinoma.

Risk Factors[edit | edit source]

While the exact cause of LCIS is not known, several risk factors have been identified. These include a family history of breast cancer, particularly in first-degree relatives, and certain genetic mutations. Hormonal factors, such as early menarche, late menopause, and use of hormone replacement therapy, may also play a role.

Management[edit | edit source]

The management of LCIS is focused on surveillance and risk reduction. Options include close monitoring with regular mammograms and clinical breast exams, chemoprevention with anti-estrogen medications such as tamoxifen, and prophylactic surgery for those at very high risk. The choice of management strategy is individualized based on the patient's risk factors and preferences.

Prognosis[edit | edit source]

While LCIS itself is not cancerous and does not metastasize, individuals with LCIS have a 7-12 times higher risk of developing invasive breast cancer in either breast, compared to the general population. The prognosis for patients with LCIS who develop breast cancer is similar to that of the general population with breast cancer, emphasizing the importance of surveillance and early detection.