Reducing delay in the diagnosis of pregnancy-associated breast cancer: how imaging can help us.

INTRODUCTION: The evaluation of breast symptoms during pregnancy or lactation can be challenging but prompt, appropriate assessment of symptoms may lead to earlier cancer detection.
METHODS: A review of breast imaging from 22 women with breast cancer during or within 1 year of pregnancy was undertaken as part of a large population-based study of gestational breast cancer. Consensus findings of three reads using the Breast Imaging Reporting and Data System lexicon were recorded.
RESULTS: The commonest presenting symptom was a lump. Diagnosis by percutaneous biopsy was made correctly in 21 of 23 lesions. Lesions were predominantly invasive ductal carcinoma (91%). One third had extensive associated ductal carcinoma in situ (DCIS). Ultrasound (US) was abnormal in all symptomatic patients. The most common sonographic finding was a solitary hypoechoic mass with irregular margins. 'Expanded stroma' with prominent ducts and architectural distortion was noted in three cases; all had extensive high-grade DCIS. In three women, bilateral breast US detected cancer in the asymptomatic breast. Mammography (performed in 86% of women) was abnormal in 74%, despite the presence of dense breast tissue in 47%. Widespread calcifications were visible in 26%, with detection of asymptomatic contra-lateral disease in one patient. MRI was performed in six patients. Background parenchymal enhancement did not impair lesion detection; however, overestimation of lesion size can occur.
CONCLUSIONS: Ultrasonography is recommended for the initial diagnosis of breast symptoms during pregnancy and lactation. A negative study should not delay direct fine needle aspiration of a palpable lesion. Mammography is indicated where initial assessment suggests malignancy. MRI may have a role in selected cases.