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

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

For a 34-year-old woman with a 3x4 cm retroareolar breast mass with nipple retraction after ultrasound, core needle biopsy is the most appropriate next diagnostic step. 1, 2

Rationale for Core Needle Biopsy

Core needle biopsy offers several advantages over other diagnostic options:

• Provides superior diagnostic information with sensitivity of 95-100% and specificity of 90-100% 2
• Allows for definitive tissue diagnosis including histologic type and receptor status if malignant 2
• Superior to fine needle aspiration biopsy (FNAB) in terms of sensitivity, specificity, and correct histological grading of palpable masses 1
• Enables evaluation of tumor receptor status, which is critical for treatment planning 1

Why Other Options Are Less Appropriate

Fine Needle Aspiration (FNA)

• While some practices show good results with FNA, larger studies demonstrate that core biopsy is superior 1
• FNA provides cytology only, without tissue architecture information needed for complete diagnosis

Mammography

• While mammography may be appropriate before tissue sampling in some cases, the presence of nipple retraction with a large retroareolar mass strongly suggests malignancy requiring immediate tissue diagnosis 1, 3
• The patient has already had an ultrasound, and the next step should be tissue sampling rather than additional imaging 1
• Mammography has reduced sensitivity in younger women with dense breasts (60-70% vs 80-90% in fatty breasts) 2

MRI

• The American College of Radiology rates MRI as "usually not appropriate" (2 out of 9) for evaluation of palpable masses with suspicious findings 2
• There is no evidence supporting MRI as the next step in evaluating a palpable mass with suspicious features 1
• MRI may be useful later for delineating extent of disease if malignancy is established by biopsy 1

Clinical Considerations

The clinical presentation raises significant concern for malignancy:

• Nipple retraction is a concerning physical finding often associated with malignancy 3
• Retroareolar carcinomas frequently present with nipple inversion or retraction 3
• Retroareolar breast carcinomas typically present as masses with irregular shape (83%), non-circumscribed margins (94%), and hypoechoic echotexture (87%) on ultrasound 4

Recommended Approach

1. Perform ultrasound-guided core needle biopsy of the retroareolar mass
2. Core biopsy should be performed before any additional imaging to avoid changes that may confuse image interpretation 1
3. If the lesion has suspicious features on ultrasound, proceed directly to image-guided biopsy 1
4. Core needle biopsy before excision helps ensure appropriate surgical planning, especially if the lesion turns out to be a malignancy requiring specific margins 2

Important Caveats

• Ensure proper correlation between the palpable abnormality and the ultrasound finding before biopsy
• If the core biopsy results are benign but discordant with imaging and clinical findings (suspicious), consider surgical excision for definitive diagnosis 5
• While some practices may use FNAB with good results, core biopsy remains the preferred method for definitive diagnosis 1