What are the microscopic findings characteristic of atypical papilloma and ductal carcinoma in situ (DCIS)?

Updated: Jun 18, 2020
  • Author: Oudai Hassan, MD; Chief Editor: Chandandeep Nagi, MD  more...
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Answer

Answer

Ductal carcinoma in situ (DCIS) involving a papilloma has microscopic features consistent with its name. It consists of an intraductal papilloma (IDP), showing a fibrovascular core with overlying layers of myoepithelial and epithelial cells, with surface involvement by a monomorphic atypical cellular proliferation like that seen in common DCIS and ADH.

The proliferation is frequently low grade and may take on various morphologies, including cribriform, solid, micropapillary, or virtually any pattern described for DCIS. High-grade cellular proliferations are also seen and are generally associated with high-grade DCIS in adjacent ductal spaces.

DCIS (blue arrow) is seen involving a small focus DCIS (blue arrow) is seen involving a small focus of this IDP (classic IDP present at black arrow). 40x.
Same tumor as above. 200x. This focus shows all th Same tumor as above. 200x. This focus shows all the features of a common, benign IDP, including a single layer of luminal epithelium and a myoepithelial layer (arrow).
Same tumor as above, at blue arrow. 200x. Low grad Same tumor as above, at blue arrow. 200x. Low grade DCIS involves the surface of the IDP at this focus, primarily showing a cribriform pattern.
Same tumor as above, at blue arrow. 400x. This foc Same tumor as above, at blue arrow. 400x. This focus shows classic cribriform, low grade DCIS.
Same tumor as above. 200x. This separate, small fo Same tumor as above. 200x. This separate, small focus of DCIS was also present on the IDP.
Same tumor as above. 400x. The focus of DCIS is lo Same tumor as above. 400x. The focus of DCIS is low grade with a classic cribriform architecture.
DCIS (blue arrow) involving an IDP (classic IDP pr DCIS (blue arrow) involving an IDP (classic IDP present at black arrow). 40x.
Same tumor as above, at black arrow. 200x. This fo Same tumor as above, at black arrow. 200x. This focus shows classic features of a benign IDP, with a single layer of luminal epithelium and a myoepithelial layer.
Same tumor as above, at blue arrow. 200x. The DCIS Same tumor as above, at blue arrow. 200x. The DCIS is characterized by a monotonous proliferation of low grade cells in a cribriform pattern.
DCIS in an IDP. 100x. This IDP is smaller than the DCIS in an IDP. 100x. This IDP is smaller than the previous examples, and the DCIS component accounts for a larger fraction of the lesion.
Same tumor as above. 200x. The DCIS is low grade w Same tumor as above. 200x. The DCIS is low grade with a predominantly cribriform architecture.
DCIS involving an IDP. 20x. This field shows areas DCIS involving an IDP. 20x. This field shows areas of common DCIS with comedo necrosis. An IDP is seen in the lower portion of the field.
Same tumor as above. 200x. DCIS is present on the Same tumor as above. 200x. DCIS is present on the surface of the IDP.
Same tumor as above. 400x. A layer of myoepitheliu Same tumor as above. 400x. A layer of myoepithelium (arrow) is seen underlying a layer of surface epithelium, confirming the suspicion this lesion is composed partly of an IDP.
Same tumor as above. 400x. This focus shows DCIS, Same tumor as above. 400x. This focus shows DCIS, with high grade nuclei and clear cytoplasm, involving the surface of the IDP.
Same tumor as above. 400x. A focus of DCIS separat Same tumor as above. 400x. A focus of DCIS separate from the IDP. This focus has identical histology to the DCIS involving the IDP.

Criteria for the diagnosis of atypical papilloma on CNB are more difficult to define. In general, the diagnosis is based on identifying an IDP involved by a cellular proliferation with features suspicious for DCIS. The most concerning such features include cellular monomorphism and architectural patterns seen in DCIS, including true cribriform and micropapillary.


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