Synchronous Luminal A Ductal Carcinoma In Situ in a Recurrent Benign Phyllodes Tumor Diagnosed Preoperatively: An Unusual Presentation of a Rare Neoplasm.

Phyllodes tumor (PT) is a rare benign tumor of the breast with a propensity to recur and metastasize. Ductal carcinoma in situ (DCIS) within PT is an extremely rare finding and is usually diagnosed postoperatively. We present a case of a 36-year-old female with a recurrent lump in her left breast diagnosed as a benign PT. Preoperatively, aspiration cytology revealed DCIS within the known case of recurrent PT. Emergency left modified radical mastectomy was performed due to an uncontrolled sudden hemorrhage from the tumor. Postoperatively, hormonal therapy was started based on immuno-histopathological findings. DCIS in PT is not encountered frequently and hence no standard management protocol exists for such cases, but when detected by histopathology, the clinical management and prognosis have to undergo a complete change. Preoperative diagnosis and proper individualized management by a multidisciplinary team that ensures clear surgical margins and planned adjuvant therapy play a crucial role in preventing the recurrence of DCIS within PT.