E1404. Should I Freak Out? Fibroadenoma or Phyllodes: Diagnosis and Management Challenges with Radiologic-Pathologic Correlation
  1. Esraa Al-Jabbari; University of Texas Medical Branch
  2. Eseosa Bazuaye-Ekwuyasi; University of Texas Medical Branch
  3. Rasha Alfattal; University of Texas Medical Branch
  4. Angelica Robinson; University of Texas Medical Branch
  5. Jing He; University of Texas Medical Branch
Fibroepithelial lesions of the breast are commonly encountered in breast imaging practice. They include a spectrum of lesions, on the benign end of the spectrum are fibroadenomas. Fibroadenomas are composed of a proliferation of both stromal and glandular elements. Further along the other end of the fibroepithelial lesion spectrum, are phyllodes tumors, which demonstrate increased cellularity and stromal proliferation as compared with fibroadenomas. They can be categorized as benign, borderline, or malignant depending on histopathology; however, the vast majority of phyllodes tumors are benign. Knowledge of the imaging features can assist in refining the differential diagnosis and guiding appropriate management.

Educational Goals / Teaching Points
The purpose of this educational exhibit is to illustrate the role of imaging in the detection of fibroepithelial lesions, highlight certain imaging feature and patients’ demographics that may assist in the narrowing the differential diagnosis. Additionally, this exhibit will recognize diagnostic challenges and emphasize on the importance of understanding biopsy results and the next step in the management.

Key Anatomic/Physiologic Issues and Imaging Findings/Techniques
Fibroepithelial lesions may demonstrate some characteristic features on mammography, ultrasound, and MR that can suggest one over the other and differentiate them from other pathologies. Mammography and ultrasound are routinely used to workup of possible fibroepithelial lesion. Breast MRI typically is not used for evaluation of a potential fibroadenoma; however, a fibroepithelial lesion may be discovered during MRI for other reasons. Fibroadenomas are more common than phyllodes tumors, usually seen in younger patients (usually in their 20s and 30s) and measure mostly less than 3 cm. Fibroadenomas usually shrink and involute with time, however, they are typically hormonal sensitive and can grow during pregnancy. Typically, fibroadenomas do not recur after excision. On imaging, fibroadenomas are usually circumscribed, homogenously hypoechoic with or without echogenic septation/ calcifications. Phyllodes tumors can be benign, borderline, or malignant (mostly benign). The patients are usually older than patient with fibroadenomas (average age is 45 years). Local recurrence can happen most notably in larger or malignant lesions. On imaging, Phyllodes tumors are frequently large (larger than 3 cm), demonstrate complex echogenicity with internal cystic component, and microlobulated margins. Calcifications are rare. Increased internal and peripheral vascularity can be detected. Definitive diagnosis of fibroepithelial lesions generally requires biopsy. When biopsy results confirm “fibroepithelial lesion,” surgical excision is typically recommended as phyllodes tumor cannot be excluded.

Fibroepithelial lesions are common and encountered almost daily in breast imaging practice. Being familiar of their imaging characteristics and understanding the management of core biopsy results helps to refine the differential diagnosis. Therefore, radiologic and pathologic correlation is essential to guide further management.