Hormone Effects

Eva C. Gombos, MD

Terminology

Definitions

Hormone effects: Enhancement and morphological changes induced by differences in hormonal status
Hormone replacement therapy (HRT): Exogenous hormone administration in postmenopausal patients
Selective estrogen receptor modulators (SERMs)
- Selectively inhibit or stimulate estrogen-like action in various tissues (distinguished from pure receptor agonists and antagonists)

Anatomy-Based Imaging Issues

Overview

Normal breast tissue enhances post contrast
- Estrogens cause parenchymal hyperemia, leading to increased enhancement
- Degree and pattern of enhancement vary cyclically in normal premenopausal breast
- Maximum enhancement is expected just before and after menstruation (during 1st and 4th weeks)
Menstrual cycle, pregnancy, lactation, and HRT may have profound effects on enhancement of normal tissue

Imaging Recommendations

Document menstrual status (date of last menstruation)
Inquire possibility of pregnancy, lactation, or HRT
Premenopausal women: Ideally during days 7-14 of cycle; may not be feasible
- Decreased enhancement in > 50% at repeat MR exams
- BI-RADS 3A is used in some facilities to recommend very close interval follow-up (6-8 weeks)
Pregnancy: MR is not advised as Gd-DTPA is known to cross placenta
- Ultrasound and mammography are recommended in pregnant patients with suspicious abnormality
Lactation: Extreme enhancement is typical but variable
- Minimal Gd-based contrast is secreted into breast milk; ACR guidelines now state it is safe to continue nursing after contrast
Postmenopausal women: Typically parenchymal atrophy and less enhancement

Imaging Pitfalls

Hormonally induced enhancement may mimic disease when focal and rapid; reduced specificity
Hormonally induced enhancement may obscure disease; reduced sensitivity

MR Features

NMLE: Common

Distribution: Diffuse, regional, focal areas

Mass-Like Enhancement

Rarely focal exuberant enhancement may appear mass-like

Enhancement Kinetics

Most common: Low or medium wash-in and persistent delayed kinetics

Correlation with Hormone Therapy

HRT (Combined Estrogen & Progesterone)

Increases risk of breast cancer and thrombosis
Decreases/reverses menopausal parenchymal atrophy
NMLE may occur in at least 30% of patients on HRT
- Repeat examination 2-3 months after interruption of HRT can show regression of enhancement

SERMs

All SERMs decrease risk of breast cancer
Tamoxifen has antiestrogen effect on breast
- Causes ↓ enhancement and ↓ breast density
- Inhibits growth of ER(+) breast cancer

Differential Diagnosis

Normal and Benign

Hormonally responsive breast tissue ± proliferative changes
Fibroadenoma, papilloma, periductal inflammation

Malignant

DCIS &/or invasive carcinoma may present as diffuse NMLE

Implications and Management

Significance

Certain enhancement patterns may pose differential diagnostic problems
- Management must be based on level of suspicion (interval follow-up, biopsy)

Selected References

1. Delille JP et al: Physiologic changes in breast magnetic resonance imaging during the menstrual cycle: perfusion imaging, signal enhancement, and influence of the T1 relaxation time of breast tissue. Breast J. 11(4):236-41, 2005

2. Espinosa LA et al: The lactating breast: contrast-enhanced MR imaging of normal tissue and cancer. Radiology. 237(2):429-36, 2005

3. Pfleiderer SO et al: Changes in magnetic resonance mammography due to hormone replacement therapy. Breast Cancer Res. 6(3):R232-8, 2004

4. Heywang-Köbrunner SH et al: Contrast-enhanced MRI of the breast: accuracy, value, controversies, solutions. Eur J Radiol. 24(2):94-108, 1997

5. Kuhl CK et al: Healthy premenopausal breast parenchyma in dynamic contrast-enhanced MR imaging of the breast: normal contrast medium enhancement and cyclical-phase dependency. Radiology. 203(1):137-44, 1997

6. Müller-Schimpfle M et al: Menstrual cycle and age: influence on parenchymal contrast medium enhancement in MR imaging of the breast. Radiology. 203(1):145-9, 1997

Image Gallery

LACTATION: DIFFUSE BILATERAL ENHANCEMENT

Figure 1 (Top) 42-year-old asymptomatic woman with known BRCA germline mutation. T2W FS images from a surveillance MR performed on this lactating woman show multiple fluid-filled ducts containing high signal due to the breast milk. (Bottom) MIP angiomaps show dense parenchyma and diffuse enhancement throughout the fibroglandular tissue. There is no evidence of an enhancing mass. Both breasts show areas of rapid enhancement and washout. The final assessment was a BI-RADS 2. Intense general enhancement is physiologic and expected in lactating women. Underlying lesions may be obscured by the marked enhancement.

LACTATION: COMPARISON TO NON-LACTATION

Figure 1 (Top) Asymptomatic 34-year-old woman with a strong family history of breast carcinoma. Heterogeneously dense breast parenchyma is seen bilaterally on baseline surveillance MR. No suspicious enhancing lesion was found. (Bottom) One year later this patient is lactating. Surveillance MR shows exuberant enhancement throughout the enlarged breasts. No focal suspicious lesion is seen, but this pattern of enhancement limits the sensitivity of the examination.

Only gold members can continue reading. Log In or Register to continue