24/09/2026
🧬 MASS-FORMING DCIS — WHAT SHOULD THE PATHOLOGIST REPORT?
DCIS is not simply a diagnosis of “in situ carcinoma.”
The pathology report needs to capture the features that define its extent, biological grade and surgical relevance.
📏 SIZE & ARCHITECTURE • Maximum extent in mm
• Architectural patterns — solid, cribriform, papillary, micropapillary and comedo
• Presence/absence of comedo-type necrosis
🔬 NUCLEAR GRADE • Grade 1 — Low
• Grade 2 — Intermediate
• Grade 3 — High
Based on nuclear size, pleomorphism and chromatin characteristics.
📐 MARGINS • Identify the closest margin
• Report the exact distance in mm from DCIS to the inked margin
• Specify the anatomical margin involved/closest
• 2 mm remains an important clinical benchmark when DCIS is treated with breast-conserving surgery followed by whole-breast irradiation.
🎯 FRCPath takeaway:
DCIS = Size + Architecture + Necrosis + Nuclear grade + Margin status
A structured approach to DCIS reporting helps convert morphology into clinically actionable information.
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