928 – Intracystic papillary carcinoma of the breast: a case report

Abstract

Introduction: Intracystic papillary carcinoma is a rare breast neoplasm, accounting for less than 2% of malignant breast
tumors, typically presenting with favorable biological behavior and predominantly affecting postmenopausal women.
Diagnosis may be challenging due to clinical and radiological variability, as well as the limitations of core needle biopsy
in distinguishing benign from malignant papillary lesions. Management and prognosis depend on the presence of invasive components or an association with ductal carcinoma in situ.
Case report: A 63-year-old woman with no personal or family history of breast cancer presented with bloody nipple discharge from the left breast. Ultrasound revealed a dilated duct associated with an irregular hyperechoic nodule measuring 0.8×0.6×0.6 cm, classified as BI-RADS 4. Excision of the main ducts was performed. Histopathological examination
demonstrated a papillary lesion with atypia and clear surgical margins. Immunohistochemistry confirmed intracystic
papillary carcinoma, with estrogen receptor positivity in 100% of tumor cells and progesterone receptor negativity. After
oncologic evaluation, adjuvant radiotherapy was indicated. The patient remains under outpatient follow-up with no evidence of recurrence to date.
Discussion: Although intracystic papillary carcinoma generally has a favorable prognosis in the absence of invasion, it
represents a diagnostic challenge, particularly when the clinical presentation is limited to nipple discharge. Surgical excision is essential for definitive diagnosis and therapeutic planning, and the indication for adjuvant therapy should be individualized, considering surgical margins, invasive components, and hormonal profile, which highlights the importance
of a careful diagnostic approach to nipple discharge in breast surgery practice.
Ethics: Research Ethics Committee Approval (CAAE 96445926.8.0000.5245).