The Role of Preoperative MRI in Patients With

Invasive Lobular Carcinoma

Golan.O, Sperber.F, Shalmon.A, Weinstein.I, Gat.A

Breast Imaging Department

Tel-Aviv Medical Center

Invasive lobular carcinoma (ILC) was first described in 1946 by Foote and Stewart.

ILC accounts for 5-14% of breast malignancies.

Diagnostically ILC is challenging because of its veiled presentation on

clinical examination and on imaging.

Histology

ILC spreads through the breast parenchyma by means of diffuse infiltration of single rows of malignant cells in a linear fashion (Indian-file pattern) around nonneopolastic ducts.

Little disruption of the underlying anatomic structures, Little surrounding connective tissue reaction

Invasive lobular carcinoma (ILC) of the breast is known to be substantially underestimated by mammography

Because ILC frequently does not form a demonstrable mass or distort the architecture or commonly produce calcifications, and is frequently isodense with normal tissue, it is not unusual for ILC to go undetected on sequential mammograms until it becomes clinically evident.

False negative 3-16%

Mammographic Characteristics of ILC

(Ellen B.Mendelson et al AJR)

Asymmetric density without definable margins .

A Mass with spiculated margins.

No tumor discernible by mammography especially in dense breast tissue .

Microcalcifications (rare)

Ultrasound Appearance

ILC cannot be distinguished from ductal carcinoma by ultrasound.

Hypoechoic tissue is seen with varying degrees of posterior enhancement.

In their retrospective review, Selinko et al found that ILC lesions were more easily seen on ultrasound than mammography .

Measurement of tumor size plays a pivotal role in treatment planning of breast cancer

Breast conserving surgery VS Mastectomy

Neoadjuvant chemotherapy ?

ObjectiveTo evaluate MRI ability to determine the extent

of ILC compared to mammography and ultrasound, and to determine if ILC, as depicted

on MRI, correlated with histopathological findings.

Materials and methods

Retrospective study of 22 patients with biopsy proven ILC who underwent MRI (7/2005-9/2007)

Age: 32-67 years (median 50 )

MRI technique

MRI was performed using 1.5T magnet (signa GE) using 4 channels breast coil

Imaging protocol:

Bilateral parallel imaging

T2 weighted sagittal fat suppressed

T1 weighted dynamic sagittal fat suppressed 3D FSPGR before and following contrast

Subtraction, curves of enhancement and MIP.

Typical section thickness: 2-2.5 mm

Results

Mammographic findings

Mass 55%

Asymmetrical density 27%

Calcifications 9%

No mammographic findings 9%

Mammographic /ultrasound correlation

• No mammographic finding-multifocal irregular solid masses bilateral.

• Masses on mammography- irregular solid masses on US on 33% multifocal (versus 17% on mammography).

• Asymmetrical density on mammography- irregular solid masses on US.

• Calcifications on mammography- multifocal irregular solid masses on US .

MRI findings

Pattern of enhancement:

Masses 91%

Focal irregular enhancement with no dominant mass 9% .

In 27% irregular ductal enhancement was also present .

73% irregular spiculated

18% mass with irregular thick ring enhancement

Extension of the disease: In 64% more than one mass versus 54% on US and 17% on mammography

3 multifocal 4 multifocal multicentric

Size:

The median diameter of the dominant mass on MRI was 5.6cm (2.2-9cm) versus 2.7 cm (1.7-5.3cm) on US and 2.5 cm (2-5cm)

on mammography.

MRI findings

Curves of enhancement

A strong and fast enhancement with washout 45%

A more benign curve 55% (speed, intensity, washout)

Pathologic correlation27% had a mastectomy – the tumor size and the

extent of the disease was much bigger than those we saw on mammography and US and had a good correlation with MRI findings.

73% were operated after neoadjuvant chemotherapy (3 mastectomy) – better correlation to the MRI than mammography and

us.

54 years old who presented with a palpable mass on the right (UOQ) breast

RT

LT

RTRT

LT LT

42 years old who presented with a palpable mass on the right (uoq) breast

45 years old who presented with a palpable mass on the right (uoq) breast. BRCA carrier.

MIP

43 years old who presented with a palpable mass on the right (uoq) breast

MIP

Conclusions

Invasive lobular carcinoma is the second most frequent invasive breast cancer.

It is unusually discovered on screening mammography and the presenting symptom is commonly a palpable mass.

Mammography is disappointing with a high rate of false negative.

US improves the imaging of ILC but still does not show the full extent of the disease.

MRI provides the most accurate estimation of tumor size and the extent of the disease, commonly showing us a multifocal disease which is underestimated by the conventional methods.

MRI often modify the therapeutic strategy ruling out conservative procedures .

MRI of the breast should be considered as a preoperative routine patients diagnosed

with Invasive lobular carcinoma.