Core Needle Biopsies

Core Needle Biopsies

Core needle biopsies for calcifications are radiographed to document that the targeted lesion has been sampled image. The cores with calcifications may be separately submitted for more careful processing.

Numerous calcifications image in an area of columnar cell change in a core needle biopsy correlate well with the targeted lesion when found in the cores that harbored the calcifications by radiography.



  • Core needle biopsy (CNB) can be used for initial evaluation of many types of breast lesions

  • Patients with benign findings can be spared surgical excision

    • Usually no cosmetic sequelae of breast deformity or skin scarring

    • No tissue scarring that could complicate mammographic interpretation

  • Patients with malignant findings also benefit

    • Multiple lesions can be sampled; helpful in determining number of cancers and extent

      • Widely spaced or very extensive cancers may require mastectomy

    • Generally require only 1 subsequent surgical procedure to remove cancer and sample lymph nodes if necessary

    • Information can be used to guide neoadjuvant therapy for eligible patients

  • Severe complications after CNB are very rare (< 1% of procedures)

  • CNB has advantages and disadvantages in comparison to fine needle aspiration (FNA) biopsy

    • FNA uses smaller needles: 18-, 20-, or 22-gauge

      • Can be performed on palpable masses or under image guidance

      • Slides can be interpreted immediately

      • Single cells rather than tissue are removed

      • Therefore, invasive carcinoma and carcinoma in situ cannot be distinguished with certainty

      • This information is important in deciding whether to sample nodes in subsequent procedure

      • Formalin-fixed, paraffin-embedded tissue sections are preferred specimen to perform special studies for ER, PR, and HER2

    • FNA is very useful for sampling palpable or enlarged nodes detected by ultrasound prior to planned neoadjuvant therapy

      • Documents presence of positive node but leaves metastasis in place to be evaluated for treatment response

      • Response in nodal metastases has more prognostic importance than response in breast

    • FNA is also useful for distinguishing solid from cystic lesions

      • Masses that can be aspirated to completion and need no further evaluation

      • If fluid is is not bloody, cytologic examination generally not performed

Types of CNB

  • Variety of needle sizes are used

    • 16-g: Small size; use generally limited to very dense breast tissue that is difficult to penetrate

    • 14-g: Standard size

    • 11-g: Larger bore needle

  • 2 main types of devices

    • Automated, spring-loaded biopsy gun with cutting needle

      • Multiple cores are required to sample lesion; may be obtained through single puncture site using a co-axial needle system

      • May be designated as clock face locations (12:00, 3:00, 6:00, 9:00) and central

      • Used ± imaging guidance

    • Vacuum-assisted devices

      • Employ a vacuum to draw tissue into needle

      • Remove multiple contiguous cores of tissue with 1 insertion

      • Permits use of larger diameter needles yielding larger specimens

      • Can be used under stereotactic, ultrasound, or MR guidance

      • 14-g vacuum-assisted core biopsy is approximately 2x size of 14-g non-vacuum-assisted core

      • May remove entire lesion if numerous cores are taken

  • Clips

    • Generally deployed to mark site of biopsy in case excision is later required

    • Clips marketed by different manufacturers have different shapes

      • If > 1 lesion is biopsied, it is preferable to use clips of different shapes to ensure that each site can be identified

    • Clips are often deployed with gel pledgets

      • Pledgets fill cavity left by needle biopsy

      • Many are small, ovoid, rice-shaped particles; associated with chronic inflammatory reaction with giant cells

      • Larger rectangular gel pledgets are less resorbable and may be surrounded by pseudosynovial lining

      • Pledgets facilitate identification of core site in excisional specimen

      • In ˜ 20% of cases, clip is displaced from actual biopsy site; post-procedure radiograph should document location of clip

Identification of Targeted Lesion

  • Palpable lesions

    • May be sampled by freehand (TrucutTM) core needle biopsies

    • Needle biopsies without imaging tend to push lesions away rather than piercing them

    • If biopsy does not show definite mass-forming lesion (e.g., fibroadenoma or carcinoma), possibility of biopsy not sampling lesion must be considered

  • Stereotactic-guided biopsies

    • Can identify masses and calcifications

    • Masses also identified by ultrasound are more easily sampled using this technique

  • Ultrasound-guided biopsies

    • Can be used for visible lesions of any size if sufficiently suspicious

    • May be difficult to see masses < 1 cm

  • MR-guided biopsies

    • Require open coil and needles compatible with special techniques

    • Only performed for lesions that cannot be identified by other methods


Radiologist Handling

  • Biopsies for calcifications should be radiographed to ensure that calcifications have been sampled

    • Cores may be separated into those containing and not containing calcifications

    • Cores with calcifications may have more superficial sections taken during slide preparation to ensure they are not missed

    • If calcifications are not seen on initial H&E slides, additional levels can be obtained only on cores with radiologic calcifications

  • It is helpful for radiologist to wrap cores in thin paper and submit in tissue cassette in larger container of formalin

    • Ensures all tissue fragments are removed from formalin container

    • More likely to keep cores intact

    • More likely to preserve calcifications in tissue

    • As many cassettes as necessary for multiple cores can be used to ensure adequate formalin penetration and fixation

  • The time the cores are placed in formalin should be recorded to ensure they are fixed for sufficient amount of time prior to processing

  • Radiologist should provide information about targeted lesion(s)

    • Mode of detection (mammography, ultrasound, MR)

    • Type of lesion (mass, calcifications, architectural distortion, type of enhancement on MR)

      • For masses, provide shape (irregular, circumscribed/lobulated, ill defined)

      • Palpable or nonpalpable

    • Size of lesion

    • Distance between lesions if multiple lesions are present

    • Distance from prior excisional sites, if present

  • Specialized requisition forms for CNB can be utilized with relevant information in menu form

Pathology Processing

  • Cores wrapped in paper can be transferred to labeled cassette for processing

  • If there is too much tissue in cassette for adequate fixation, cores can be distributed into more cassettes

Histology Processing

  • Multiple levels are usually obtained on each biopsy

    • 3 levels are generally adequate for diagnosis

      • 3rd level should be approximately halfway through thickness of tissue

      • Allows for additional sections should additional studies be necessary

    • For MR biopsies with carcinoma, diagnosis is usually apparent on 1st level

      • Very small cancers are less likely to be detected by MR

  • Cores known to have calcifications may have superficial levels taken to make sure calcifications are not missed


General Considerations

  • Correlation with imaging findings is essential to ensure lesions are not missed

  • Requires adequate information about lesion from radiologist

  • Pathologist can document correlation with radiologic finding in some cases

    • Majority of carcinomas will be source of imaging lesion

    • Majority of fibroadenomas will be source of imaging lesion

  • In some cases there may be correlation, but pathologist cannot determine this with certainty

    • Cores for radiologic calcifications with only rare pathologic calcifications seen

    • Cores for masses with findings that do not have specific findings on core

      • e.g., lipoma, pseudoangiomatous stromal hyperplasia, hamartoma

  • In some cases, there clearly is not a correlation

    • Cores for calcifications without calcifications

      • Radiologic examination of block (direct and lateral views) may be considered to locate them in block

      • Additional deeper levels should be performed

      • Less common reasons for “calcifications” should be considered: Calcium oxalate, metallic debris from prior biopsies, gold from treatment for rheumatoid arthritis

      • Calcium oxalate is best seen using polarized light

    • Cores for mass lesions with only normal tissue identified

  • Radiology/pathology correlation conferences are useful for discussing difficult cases

Reporting Cancers

  • Ductal carcinoma in situ (DCIS)

    • Sometimes difficult to distinguish from atypical ductal hyperplasia (ADH) on CNB

      • Diagnosis may be deferred to excision for borderline lesions

    • Invasive carcinoma will be present on excision in some cases

      • More likely if targeted lesion is a mass

    • Correlation is better for vacuum-assisted biopsies that sample more tissue

      • Reduce number of cases with invasive carcinoma at surgical excision by at least 50%

    • ER may be performed on CNB

      • If results are negative, may be repeated on larger area in excision as there is often marked heterogeneity in DCIS

  • Lobular carcinoma in situ (LCIS)

    • LCIS may be present as incidental finding

    • If LCIS has atypical features, these should be clearly described

      • High nuclear grade

      • Necrosis

      • Association with calcifications

    • Excision is recommended for LCIS with atypical features due to higher risk of finding invasive carcinoma or DCIS

  • Invasive carcinoma

    • Useful to report maximum size as seen on CNB

      • Generally smaller than actual size

      • However, size on excision may be smaller than on core for small cancers

      • Helpful to judge reliability of special studies: If only small area of cancer is present on CNB and results are negative, repeat studies on excision may be warranted

      • Clinicians must understand that size on core should not be added to size on excision

    • Histologic type and grade are helpful for counseling patients about likely prognosis and treatment

      • Grade may be underscored in ˜ 1/3 of cases compared to excisions; rarely overscored

      • Special histologic types need to be reevaluated on excisional specimen

    • ER, PR, and HER2 may be evaluated

      • CNBs usually have minimal ischemic time and optimal formalin fixation

      • Minimum time for fixation is 6 hours for adequate antigen preservation; shorter times may result in false-negative results

      • However, amount of tumor available may be limited

      • In other cases, tissue disruption and crushing may make evaluation difficult or impossible

      • Repeat of negative results on larger areas of carcinoma on excision should be considered

      • Studies on larger areas of carcinoma may also be better for detecting cases of heterogeneous expression

    • For patients undergoing neoadjuvant treatment, results on CNB may be only documentation of their carcinoma

Jul 6, 2016 | Posted by in PATHOLOGY & LABORATORY MEDICINE | Comments Off on Core Needle Biopsies

Full access? Get Clinical Tree

Get Clinical Tree app for offline access