Encapsulated papillary carcinoma of the breast clinicopathological features and management: Could sentinel lymph node biopsy be exempted?

Background: Papillary lesions in the breast pose diagnostic and therapeutic challenges. Encapsulated papillary carcinoma (EPC) is a rare breast cancer. However, evidence-based guidelines are limited. For this reason, there is no complete clarity in diagnosis and treatment management, and there are insufficient studies in the literature. This study aimed to examine the necessity of sentinel lymph node sampling in the management of EPC, in line with patients' clinicopathological data.

Methods: We retrospectively screened patients with EPC in our clinic between January 2012 and March 2022. We recorded and statistically evaluated patients' demographic, clinical, radiological, pathological, and treatment management.

Results: Sixty-four patients with EPCs were identified. The final pathologic evaluation revealed that 19 patients (18.7%) had pure EPC, 27 patients (43.7%) had EPC with associated ductal carcinoma in situ and 18 patients (37.5%) had EPC associated with invasion. The mean age was 61 years, and two patients were male. Breast-conserving surgery was performed in 62 patients, and simple mastectomy was performed in two patients. Sentinel lymph node biopsy (SLNB) was positive in only one patient. Sixty-three patients with EPC were hormone receptor-positive, and one patient was triple-negative and was associated with invasion. None of the patients died, one had a local recurrence, and a mastectomy was performed.

Conclusions: The overall prognosis and long-term survival of patients with EPC were excellent. Our study and the current literature indicate that routine SLNB is overtreatment because surgical excision with negative margins is sufficient in EPC cases and lymph node metastasis is rare, even with an invasive component.