Breast MRI in clinically and mammographically occult breast cancer presenting with an axillary metastasis: a systematic review.
BACKGROUND
Axillary metastatic lymphadenopathy with no primary tumour identified in the breast on physical examination, mammography or ultrasound is referred to as occult breast cancer. The goal of this systematic review is to give an overview of the value and additional considerations of using breast MRI in occult breast cancer.


METHODS
The databases of Pubmed, Embase, CINAHL and the Cochrane library were searched for studies addressing the use of breast MRI in occult breast cancer. Cross-referencing was used to find additional articles.


RESULTS
8 retrospective studies were included. Breast MRI can detect an otherwise occult breast cancer in more than two thirds of patients with a high sensitivity but lower specificity. In 80% of patients MRI detected lesions could be localized again by using ultrasound. Furthermore the size and localization of the lesions found on MRI most often correlated closely with findings at pathology. Breast MRI also provided the possibility of breast conserving surgery in one thirds of patients.


CONCLUSIONS
Breast MRI can result in additional detection of otherwise occult lesions in occult breast cancer. Because of low specificity of malignant lesion detection by breast MRI, lesions should be histologically confirmed. This can be achieved either by MRI or ultrasound guided biopsy, as long as all MRI detected lesions are histologically checked. Routine application of breast MRI in occult breast cancer may also alter locoregional treatment by offering the possibility of breast conserving surgery in one thirds of patients.
de Bresser
J
J
Department of Surgery, Orbis Medical Centre, Sittard, The Netherlands. J.deBresser@umcutrecht.nl
de Vos
B
B
van der Ent
F
F
Hulsewé
K
K
D001365:Axilla; D001707:Biopsy, Needle; D001940:Breast / Q000473:pathology*; D001943:Breast Neoplasms / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery; D005260:Female; D006801:Humans; D008207:Lymphatic Metastasis; D008279:Magnetic Resonance Imaging; D053783:Magnetic Resonance Imaging, Interventional; D008327:Mammography; D015412:Mastectomy, Segmental; D012680:Sensitivity and Specificity