Approach

Ductal carcinoma in situ (DCIS) in women is often asymptomatic. It is frequently diagnosed during routine screening mammography.

Lobular carcinoma in situ (LCIS) is typically asymptomatic and usually discovered incidentally. There is no classic mammographic pattern for LCIS.

Clinical assessment

Women diagnosed with DCIS are often asymptomatic. Rarely, DCIS may present as an eczematous-like rash on the nipple if presenting as Paget's disease. In the absence of medical attention, a woman may present with ulceration. Other uncommon presenting symptoms of DCIS include nipple discharge (which may be bloody) or a breast lump.

The first symptom in males diagnosed with DCIS is generally bloody nipple discharge.[72] 

LCIS often occurs in conjunction with other clinically identified malignant or benign lesions such as fibroadenoma, cysts, papilloma, papillomatosis, fat necrosis, or breast abscesses.

Imaging

At routine mammographic screening (which may comprise digital breast tomosynthesis [three-dimensional mammography] alongside conventional two-dimensional mammography), a finding of clustered microcalcifications in one breast, and absence of a soft-tissue abnormality, indicates DCIS. Calcifications may be linear, branching, or bizarre in comedo DCIS. Non-comedo DCIS may not be calcified or may present as fine granular powdery calcifications.

Mammographic magnification views may be employed to evaluate and count microcalcifications.

LCIS does not have classic mammographic findings.

For non-specific lesions, magnification views, with or without ultrasound, are generally performed. To differentiate cystic from solid lesions, ultrasound is performed.

Additional imaging studies

Mammographic sensitivity is lower in women with dense breasts, therefore supplemental imaging (e.g., ultrasound, MRI) may be warranted in these women.[53][73][74]​​​​​​[75]

MRI may be especially helpful in detecting high-grade DCIS.​​​[76][77][78]​​​​​​​​​​​​​​​​​​​​ Although MRI can accurately detect additional lesions and contralateral cancer not identified using conventional imaging in primary breast cancer, MRI findings should be pathologically verified because of the high false-positive rate.[79][80]​ Breast MRI is not routinely recommended for diagnostic evaluation because of the risk of false positives and potential for over-treatment.[81][82]​ Breast MRI should not be used routinely for the preoperative work-up of patients with DCIS.[83][84][85][66]​​​

Do not perform positron emission tomography, computed tomography, or radionuclide bone scans in the staging of early breast cancer at low risk for metastasis; there is no evidence of benefit in asymptomatic individuals with newly identified DCIS.[86][87]​​​

Biopsy

Core needle biopsy should be performed if a suspicious breast lesion is identified on imaging. Results are diagnostic, but it may underestimate the extent of disease.[88][89]

Stereotactic (mammographically guided) core needle biopsy is the diagnostic procedure of choice in the setting of microcalcifications; it is nearly as accurate as excisional biopsy, with fewer complications.[90] Core needle biopsy may, however, underestimate the extent of disease.[91][92]​ 

Architecturally, papillomas can cause false-positives. Furthermore, many breast malignancies contain elements of both in situ and invasive carcinoma. As such, a core needle biopsy demonstrating one component does not exclude the other.

Ultrasound-guided core needle biopsy is preferred if a non-palpable mass is found on imaging.

Excisional biopsy

Provides a complete diagnosis and the opportunity for treatment. However, it requires surgery and is associated with poorer cosmesis than needle biopsy.

Excisional biopsy is recommended:[53]

  • If core needle biopsy cannot be performed

  • When core needle biopsy results are indeterminate, or benign and discordant with imaging

  • If there is atypical ductal hyperplasia (ADH)

  • For non-classic LCIS (pleomorphic or florid)

  • For select patients (e.g., with classic LCIS, atypical lobular hyperplasia, flat epithelial atypia, papillomas without atypia, fibroepithelial lesions favouring fibroadenoma), depending on level of suspicion.

Pathological analysis of biopsy

Necessary for scoring by nuclear grade and architecture.

Note that the US Food and Drug Administration (FDA) has issued a safety alert stating that ductal lavage (also known as nipple fluid aspirate test) is not a replacement for mammography, other imaging studies, or biopsy.[93] Nipple aspirate fluid cytology is limited by poor sensitivity.[94]

Sentinel lymph node biopsy

Sentinel lymph node biopsy (SLNB) may be considered in the setting of:[66]

  • mastectomy for DCIS,

  • excision in an anatomical location compromising the performance of a future SLNB procedure, or

  • oncoplastic breast conserving surgery.

SLNB should not be routinely performed in women with preoperative (biopsy-determined) pure DCIS who are undergoing breast-conserving surgery, but it may be considered if there is high suspicion for invasive disease or axillary metastasis (e.g., palpable mass, extensive microcalcifications).[66][95]​​​[96]

Hormone receptor testing

Assessing oestrogen receptor status (using immunohistochemical staining) is recommended to help determine potential benefit of endocrine therapy for adjuvant treatment or breast cancer risk reduction.[66][97]

Assessing progesterone receptor status is optional.[66][97]

Genetic evaluation

Genetic counselling and germline testing for high-penetrance breast cancer susceptibility genes (e.g., BRCA1, BRCA2, CDH1, PALB2, PTEN, STK11, and TP53) should be considered for women at high risk for hereditary breast cancer (e.g., based on personal and/or family history).​[63][65][66][98]​​[99][100]

Genetic testing for a specific pathogenic variant can be carried out, if known; germline multigene panel testing is recommended if the pathogenic variant is unknown or if personal and/or family history suggests involvement of more than one pathogenic variant.[63][101]​ Selection of the specific multigene panel should take into account the patient's personal and family history. Results can inform prognosis and may highlight risk among family members.

See Primary invasive breast cancer (Screening) topic for specific criteria for genetic counselling and testing.

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