Lobular carcinoma in situ

Last updated: June 13, 2023

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Summarytoggle arrow icon

Lobular carcinoma in situ (LCIS) is a noninvasive proliferative lesion of the breast that arises from the terminal ductal lobular units. It is typically asymptomatic; detected incidentally on core needle biopsy, most commonly in premenopausal women aged ∼ 50 years. Histologically, LCIS is divided into classic LCIS and LCIS variants, which include pleomorphic LCIS and florid LCIS. Although LCIS is a nonmalignant lesion, it is a risk factor for invasive breast cancer in the ipsilateral and contralateral breasts. Management is challenging, as the data on risk stratification of LCIS and the long-term benefits of treatment options are lacking. Treatment options include close clinical surveillance, surgical excision to rule out concurrent breast cancer, and prophylactic strategies such as chemotherapy or bilateral mastectomy to minimize the risk of developing breast cancer.

Epidemiologytoggle arrow icon

LCIS was previously classified as a premalignant lesion (i.e., Tis). It is now considered a benign entity and has been removed from the 8th edition of the AJCC TNM cancer staging system. [7]

Epidemiological data refers to the US, unless otherwise specified.

Classificationtoggle arrow icon

Histological classification of LCIS [8][9]
Types Characteristics
Classic LCIS (CLCIS)
LCIS variants [8] Pleomorphic LCIS (PLCIS)
  • Marked distortion and distention of the terminal duct lobular units
  • Form a mass-like appearance
  • Apocrine features may be present.
  • Central necrosis and microcalcifications

Clinical featurestoggle arrow icon

  • Asymptomatic; no specific findings (no mass or calcifications)
  • Approx. 55% are multicentric and approx. 35% are bilateral [3][9]

Classic LCIS is typically not apparent on clinical breast examination or imaging. In PLCIS, pleomorphic calcifications may be seen on mammography. [3]

Diagnosticstoggle arrow icon

Treatmenttoggle arrow icon

Quality evidence on risk stratification and optimal management of LCIS is lacking. Refer patients with LCIS to oncology. Shared-decision making is recommended when selecting a treatment strategy.

Close clinical surveillance [3][5]

Surgical excision (breast conservation surgery) [11][12]

  • Consider for LCIS variants (to rule out concurrent invasive breast cancer).
  • The need to achieve R0 resection is unclear as the recurrence rates for close or positive margins are not significant.

Surgical excision to rule out associated invasive breast cancer is not routinely recommended for classic LCIS. [12]

Breast cancer risk-reduction options [2][6]


Bilateral prophylactic mastectomy

Although chemoprevention and bilateral prophylactic mastectomy significantly decrease the risk of breast cancer in patients with LCIS, they are associated with significant adverse effects and the impact of these interventions on overall survival is modest. [2][6]

Referencestoggle arrow icon

  1. $Contributor Disclosures - Lobular carcinoma in situ. None of the individuals in control of the content for this article reported relevant financial relationships with ineligible companies. For details, please review our full conflict of interest (COI) policy:.
  2. King TA, Pilewskie M, Muhsen S, et al. Lobular Carcinoma in Situ: A 29-Year Longitudinal Experience Evaluating Clinicopathologic Features and Breast Cancer Risk. Journal of Clinical Oncology. 2015; 33 (33): p.3945-3952.doi: 10.1200/jco.2015.61.4743 . | Open in Read by QxMD
  3. Wen HY, Brogi E. Lobular Carcinoma In Situ. Surg Pathol Clin. 2018; 11 (1): p.123-145.doi: 10.1016/j.path.2017.09.009 . | Open in Read by QxMD
  4. Carniello JS, Giri D, De Brot M, Andrade V, King T. Multifocality and Bilaterality of Lobular Carcinoma In Situ in Women with Synchronous Breast Malignancies. Am J Clin Pathol. 2016; 146 (suppl_1).doi: 10.1093/ajcp/aqw159.085 . | Open in Read by QxMD
  5. Thomas PS. Diagnosis and Management of High-Risk Breast Lesions. Journal of the National Comprehensive Cancer Network. 2018; 16 (11): p.1391-1396.doi: 10.6004/jnccn.2018.7099 . | Open in Read by QxMD
  6. Wong SM, Stout NK, Punglia RS, Prakash I, Sagara Y, Golshan M. Breast cancer prevention strategies in lobular carcinoma in situ: A decision analysis. Cancer. 2017; 123 (14): p.2609-2617.doi: 10.1002/cncr.30644 . | Open in Read by QxMD
  7. Giuliano AE, Edge SB, Hortobagyi GN. Eighth Edition of the AJCC Cancer Staging Manual: Breast Cancer. Ann Surg Oncol. 2018; 25 (7): p.1783-1785.doi: 10.1245/s10434-018-6486-6 . | Open in Read by QxMD
  8. Tan PH, Ellis I, Allison K, et al. The 2019 World Health Organization classification of tumours of the breast. Histopathology. 2020; 77 (2): p.181-185.doi: 10.1111/his.14091 . | Open in Read by QxMD
  9. Kumar V, Abbas AK, Aster JC. Robbins & Cotran Pathologic Basis of Disease. Elsevier Saunders ; 2015
  10. ACOG. Practice Bulletin No. 164 Diagnosis and management of benign breast disorders. Obstetrics & Gynecology. 2016; 127 (6): p.e141-e156.doi: 10.1097/aog.0000000000001482 . | Open in Read by QxMD
  11. Sokolova A, Lakhani SR. Lobular carcinoma in situ: diagnostic criteria and molecular correlates. Modern Pathology. 2020; 34 (S1): p.8-14.doi: 10.1038/s41379-020-00689-3 . | Open in Read by QxMD
  12. Flanagan MR, Rendi MH, Calhoun KE, Anderson BO, Javid SH. Pleomorphic Lobular Carcinoma In Situ: Radiologic-Pathologic Features and Clinical Management. Ann Surg Oncol. 2015; 22 (13): p.4263-9.doi: 10.1245/s10434-015-4552-x . | Open in Read by QxMD
  13. Visvanathan K, Hurley P, Bantug E, et al. Use of Pharmacologic Interventions for Breast Cancer Risk Reduction: American Society of Clinical Oncology Clinical Practice Guideline. Journal of Clinical Oncology. 2013; 31 (23): p.2942-2962.doi: 10.1200/jco.2013.49.3122 . | Open in Read by QxMD

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