# The spectrum of breast in situ papillary carcinomas with invasion and invasive breast carcinomas with papillary features: an overview of histological subtypes and diagnostic challenges

## TL;DR

This paper reviews different types of invasive breast cancers with papillary features, focusing on their classification, diagnosis, and clinical implications.

## Contribution

The paper provides an updated overview of the histological subtypes and diagnostic challenges of invasive breast carcinomas with papillary features.

## Key findings

- IBCP includes six distinct subtypes with varying architecture and invasive behavior.
- Standardized diagnostic criteria are needed to improve classification and patient outcomes.
- Recognizing these subtypes is clinically relevant for prognosis and treatment decisions.

## Abstract

Invasive breast carcinomas with papillary features (IBCP) constitute a distinct and morphologically diverse group of breast cancers characterised by varying degrees of papillary architecture and invasive behaviour. IBCP encompass (1) papillary carcinoma in situ associated with invasion, (2) invasive solid papillary carcinoma (ISPC), (3) encapsulated papillary carcinoma (EPC)‐like invasive carcinoma, (4) Papillary DCIS‐like invasive carcinoma, (5) high‐grade carcinomas with EPC‐like or SPC‐like morphology, and (6) invasive papillary carcinoma not otherwise specified (IPC), including the tubulopapillary pattern. This review summarises the evolving classification, histopathological features, diagnostic criteria, differential diagnoses, clinical prognosis, and treatment implications of various subtypes of IBCP. Particular attention is given to the diagnostic challenges and clinical relevance of recognising these tumour types. Standardised diagnostic criteria and further research into the biological behaviour of these entities are essential to guide appropriate management and improve prognostication.

Invasive breast carcinomas with papillary features (IBCP) comprise diverse subtypes with variable architecture, histopathology, and clinical behaviour. This review outlines evolving classification, diagnostic criteria, and treatment implications, highlighting challenges in distinguishing in situ from invasive lesions. Standardised diagnostic approaches are essential to improve consistency, prognostication, and patient management.