# Wide Margins are Still Relevant: A Case of a Well-Circumscribed Borderline Phyllodes Tumor With a Satellite Nodule in a Re-excision Margin

## TL;DR

This paper discusses a case where a borderline phyllodes tumor had a satellite nodule in a re-excision margin, highlighting the importance of wide surgical margins to reduce recurrence.

## Contribution

The case emphasizes the need for wide margins in borderline phyllodes tumors due to potential satellite foci and recurrence risks.

## Key findings

- A satellite nodule was found in a previously negative margin after re-excision.
- Wide negative margins are recommended to reduce local recurrence in borderline phyllodes tumors.
- Current understanding of peritumoral tissue and satellite foci remains limited.

## Abstract

Phyllodes tumors (PTs) of the breast are rare fibroepithelial neoplasms with high rates of local recurrence (LR) for which surgical excision remains the mainstay of treatment. The recommended surgical margin width is debated and varies based on the histologic grade. We present a case of a middle-aged woman with a well-circumscribed borderline PT who underwent margin re-excision, with a distinct focus of the PT detected at a previously negative margin. Given the high rates of LR and potential for histologic upgrade at the time of recurrence, combined with the current limited understanding of peritumoral tissue and possible satellite foci, a wide negative margin remains the recommendation for borderline PTs.