1. MedPix Medical Image Database COW - Case of the Week Case Contributor: Russell A. Patterson Affiliation: Uniformed Services University

2. MedPix No: 8167 - History Pt Demographics: Age = 59 y.o. Gender = woman History (can include gestational age, or age in days, weeks, months): 59 y/o female with focal left breast pain x 2-3 months with increased risk by the Gail model. Mammogram was normal. Breast ultrasound was normal without any evidence of mass or cystic structure. Downloaded by (-1)

3. MedPix No: 8167 - EXAM & LABS Physical Exam and Laboratory: Left breast tenderness on palpation. No masses, nodules or changes in the skin.

4. Ductal Carcinoma in Situ (DCIS) Axial MRI of the breast with enhancing mass after gadolinium administration Downloaded by (-1)

5. Ductal Carcinoma in Situ (DCIS) Axial MRI with gadolinium shows enhancing mass. Downloaded by (-1)

6. Ductal Carcinoma in Situ (DCIS) MRI of the breast shows needle for biopsy outside the breast Downloaded by (-1)

7. Ductal Carcinoma in Situ (DCIS) MRI with biopsy needle obscuring lesion Downloaded by (-1)

8. Ductal Carcinoma in Situ (DCIS) MRI with needle tract artifact obscuring lesion Downloaded by (-1)

9. FINDINGS Image Findings: Breast MRI showed spiculated enhancing mass in anterior 1/3 of Left breast.

10. DIFFERENTIAL DIAGNOSIS What is your Differential Diagnosis? Differential Diagnosis for these findings in this case: - Malignant neoplasmductal carcinoma, lobular carcinoma, inflammatory carcinoma - Fibroadenoma - Abscess -

11. Diagnosis: Ductal Carcinoma in Situ (DCIS) Dx Confirmed by: Needle placement for biopsy using MRI guidance

12. DISCUSSION Discussion (include references): Given the increased use of mammographic screening over the past few decades, the DCIS is the most rapidly growing subgroup of breast cancer. DCIS was newly diagnosed over 55,000 times in 2003. As a direct precursor to invasive breast cancer, diagnosing DCIS is important to preventing widespread disease. For a pt such as this, where mammography and US showed no abnormalities, but she was still having pain, MRI is a logical next step. Almost all invasive cancers will enhance with gadolinium on MRI (95- 100% sensitivity); it is less for DCIS. However, in this pt it did enhance. Also of note, MRI can be helpful in determining the extent of disease spread posteriorly (chest wall, muscle, etc.) However, the routine use of breast MRI is being studied and compared with that of mammagraphy. MRI is often much more expensive, less available, and may have a higher false positive rate for enhancing benign lesions.