E3325. Beyond the Norm: Decoding Giant Breast Masses - An Imaging Insight
  1. Erika Castro; University of California San Diego Health
  2. Luis Monterroso; University of California San Diego Health
  3. Sousabeh Fazeli; University of California San Diego Health
  4. Vivian Lim; University of California San Diego Health
  5. James Stepenosky; University of California San Diego Health
  6. Mohammad Eghtedari; University of California San Diego Health
  7. Haydee Ojeda-Fournier; University of California San Diego Health
Screening mammography aims to identify potential breast cancers when they are small to start treatment early and improve survival. Breast masses are common in breast imaging, with most masses being benign. Occasionally, giant breast masses, defined as lesions exceeding 5 cm in diameter, are encountered. There is a broad differential diagnosis for giant breast masses, including benign and malignant etiologies. Despite many of these masses being benign, they may cause significant pain or distress to the patient, highlighting the need for prompt diagnosis. This educational exhibit aims to provide a comprehensive overview of giant breast masses, focusing on imaging findings and techniques crucial for accurate diagnosis and management and identifying important differential considerations via a pictorial review. Exhibit outline: introduction. definition, prevalence, benign and malignant etiologies of giant breast masses, characteristic imaging findings, factors contributing to rapid growth, imaging modalities to evaluate giant masses, multimodality examples, multidisciplinary management, potential complications, and conclusion.

Educational Goals / Teaching Points
Know the definition and epidemiology of giant breast masses, emphasizing their rarity and unique characteristics; understand the key anatomic and pathophysiologic considerations that contribute to the development and growth of giant breast masses; recognize imaging findings associated with giant breast masses, including mammography, ultrasound, and MRI; and recognize the importance of multidisciplinary collaboration for appropriately managing patients with giant breast masses.

Key Anatomic/Physiologic Issues and Imaging Findings/Techniques
Giant breast masses may be detected on screening or evaluated with diagnostic breast imaging in patients with symptoms or a palpable finding. Even with multimodality imaging evaluation, it may be difficult to confidently provide a diagnosis, highlighting the need for tissue sampling in many cases. A BI-RADS 3 assessment and appropriate follow-up may be sufficient in other cases. Benign etiologies include fibroadenoma, low-grade phyllodes tumor, pseudoangiomatous stromal hyperplasia (PASH), sclerosing adenosis, lipoma, hamartoma, hematoma/seroma, and abscess. Malignant etiologies include lymphoma and high-grade phyllodes tumor, and less commonly, advanced or neglected breast cancer or sarcoma. Characteristic imaging findings: fat-containing (hamartoma and lipoma), circumscribed margins (fibroadenoma, phyllodes tumor, PASH, lipoma, hamartoma, hematoma/seroma), irregular shape (abscess and breast cancer).

Giant breast masses are uncommon and may present on screening or diagnostic breast imaging. This educational exhibit aims to provide the knowledge and tools required to make accurate diagnoses, formulate appropriate treatment plans, and help radiologists recognize common etiologies and guide clinical management.