Ductal carcinoma in situ and invasive carcinoma originating in a Fibroadenoma with concurrent benign phyllodes tumor: A case report.

INTRODUCTION AND IMPORTANCE: This case report presents a rare occurrence of multiple bilateral breast fibroadenomas, one evolving into ductal carcinoma in situ (DCIS) and invasive carcinoma, occurring simultaneously with a benign phyllodes tumor in the same breast. The importance of this case lies in emphasizing the crucial need for surveillance in patients with a long history of fibroadenomas and the necessity to investigate any rapid change in the size of fibroadenoma.

CASE PRESENTATION: A 35-year-old multiparous female with a 17 year history of bilateral multiple breast lumps presented with recent onset of right breast pain and yellowish nipple discharge. Two lumps in her right breast had demonstrated an increase in size. Examination revealed a significant mass in the retroareolar region of the right breast and another at the 2 o'clock position. Histopathological examination of the biopsy specimens revealed fibroadenoma and benign phyllodes tumor. The patient underwent a bilateral breast lumpectomy. Further histopathological examination revealed ductal carcinoma in situ and invasive carcinoma within a complex fibroadenoma in the right breast and benign phyllodes tumor. Sentinel lymph node biopsy was negative. She had adjuvant radiations and trastuzumab. Regular follow-ups show no recurrence.

CLINICAL DISCUSSION: Fibroadenomas are usually benign but rarely undergo malignant change. Quick response to size changes and early detection greatly enhance patient results.

CONCLUSION: Ductal carcinoma in situ and invasive breast cancer, a rare malignancy found within a fibroadenoma, necessitates histopathological specimens and immunohistochemical results for accurate diagnosis. Survival rates are significantly enhanced through a multidisciplinary approach.