What is the next step in management for a 25-year-old female with a 3 cm breast lump confirmed by ultrasound to be a fibroadenoma (Fibroadenoma), who is requesting excision due to concerns about the lump?

Management of a 3 cm Fibroadenoma in a 25-Year-Old Female

Initial Approach

Core needle biopsy (CNB) is the recommended next step for this 25-year-old female with a 3 cm breast lump confirmed by ultrasound to be a fibroadenoma who is requesting excision. 1

The National Comprehensive Cancer Network (NCCN) guidelines specifically recommend tissue sampling via core needle biopsy for solid breast masses that are large (>2-2.5 cm) to exclude phyllodes tumor, which can mimic fibroadenoma on imaging 1. This patient's fibroadenoma falls into this category at 3 cm.

Rationale for Core Needle Biopsy

Core needle biopsy is preferred in this case for several important reasons:

• High diagnostic accuracy: CNB has superior sensitivity (95-100%) and specificity (90-100%) 1
• Exclusion of phyllodes tumor: Large fibroadenomas (>2 cm) require histological confirmation to rule out phyllodes tumor 1, 2
• Surgical planning: CNB before excision helps ensure appropriate surgical planning, especially if the lesion turns out to be a phyllodes tumor requiring wider margins 1
• Patient anxiety: The NCCN guidelines acknowledge patient anxiety as a valid consideration when deciding on tissue sampling or surgical excision 1

Why Not Other Options?

1. Mammogram (Option B): Not indicated as the primary next step in women under 30 years with a palpable mass already evaluated by ultrasound 1. Ultrasound is the preferred initial imaging for women under 30 years with breast symptoms.

2. Excision after CNB (Option A): While excision may ultimately be performed, it should only occur after CNB confirms the diagnosis, not as the immediate next step.

3. Self-examination monthly (Option D): Inadequate management for a large (3 cm) fibroadenoma, especially when the patient is concerned and requesting removal. Surgical intervention is indicated by size greater than 2 cm and patient anxiety 2.

Management Algorithm

1. Perform CNB to confirm diagnosis and rule out phyllodes tumor or other pathology

2. Based on CNB results:

   • If confirmed simple fibroadenoma: Proceed with excision (given patient's request and size >2 cm)
   • If complex fibroadenoma: Surgical excision is indicated 2
   • If phyllodes tumor: Wide local excision with 1 cm margins would be required 1

3. Post-excision:

   • Histopathological examination of the excised specimen
   • Follow-up as indicated based on final pathology

Important Considerations

• While some studies suggest that fibroadenomas diagnosed by ultrasound in young women may not always require biopsy 3, this patient's case has specific features warranting CNB:

  • Large size (3 cm)
  • Patient's request for removal
  • Need to exclude phyllodes tumor

• The risk of malignancy in fibroadenomas is rare (0.58% in one study) 4, but the risk cannot be completely excluded without tissue sampling, especially in larger lesions.

• Ultrasound-guided vacuum-assisted biopsy can serve as both a diagnostic and therapeutic tool for smaller fibroadenomas, but complete excision is less likely for lesions >2 cm 5, making traditional surgical excision more appropriate after CNB in this case.