What is the next step in management for a 34-year-old lady with a 3x4 cm retroareolar breast mass and nipple retraction, after an ultrasound (US) has been performed?

Core Needle Biopsy is the Next Step for a 34-Year-Old with Retroareolar Breast Mass and Nipple Retraction

For a 34-year-old woman with a 3x4 cm retroareolar breast mass and nipple retraction who has already had an ultrasound, core needle biopsy (CNB) is the next appropriate step in management. 1

Rationale for Core Needle Biopsy

Core needle biopsy is the preferred method for obtaining a definitive tissue diagnosis in this case for several reasons:

• It provides superior diagnostic information with a sensitivity of 95-100% and specificity of 90-100% for definitive diagnosis 1
• It allows determination of histologic type and receptor status if the mass is malignant 1
• The presence of concerning clinical features (large mass size and nipple retraction) warrants tissue diagnosis regardless of imaging findings 1

Why Other Options Are Less Appropriate

1. Fine Needle Aspiration (FNA):

   • Less diagnostic accuracy compared to core needle biopsy
   • Does not provide histologic type and receptor status information
   • Not recommended as the primary diagnostic tool when a suspicious mass is present 1

2. Mammogram:

   • While mammography is the primary screening tool for breast cancer detection, it has already been preceded by ultrasound in this case
   • Mammography has reduced sensitivity in dense breast tissue (60-70%) compared to fatty breasts (80-90%) 1
   • Retroareolar carcinomas can be mammographically occult in some cases 2

3. MRI:

   • The American College of Radiology rates MRI as "usually not appropriate" (rating of 2 out of 9) for evaluation of palpable masses with suspicious findings 1
   • MRI should not delay obtaining a tissue diagnosis when clinical findings are suspicious

Clinical Significance of Presenting Features

The patient's presentation has several concerning features:

• Large mass size (3x4 cm)
• Nipple retraction
• Retroareolar location

Nipple retraction is particularly concerning as it has been associated with retroareolar carcinomas 2. Studies have shown that retroareolar carcinomas commonly present as palpable masses, with some cases showing associated nipple inversion or retraction 2, 3.

Importance of Tissue Diagnosis

A core needle biopsy is essential in this case because:

• It helps ensure appropriate surgical planning 1
• The suspicious physical examination (nipple retraction) should prompt biopsy regardless of imaging findings 1
• Retroareolar masses with suspicious features have a high likelihood of malignancy and require definitive diagnosis 3

Practical Considerations

When performing the core needle biopsy:

• Ultrasound guidance is recommended for accurate targeting of the mass
• Multiple core samples should be obtained to ensure adequate sampling
• The procedure should be performed by an experienced operator to minimize complications and maximize diagnostic yield

Remember that even if ultrasound findings appear benign, the presence of concerning clinical features (nipple retraction) warrants tissue diagnosis, as clinical examination has a sensitivity of 90-100% for detecting malignant masses 1.