INTRADUCTAL PAPILLARY CARCINOMA
- These tumors are either solitary or multiple. solitary lesions are central and multiple lesions are distributed peripherally
- Accounts for less than 2% of breast malignancies
- Age group – common in elderly ( more than 30 years)
- Papillary lesions are associated with abnormalities in 16q. In papillary carcinoma loss of heterozygosity on chromosome 16p13 is noted
Gross –
- These are usually well circumscribed
- Bleeding into the tumor may produce hemorrhagic cystic lesion and may be tan or gray in appearance
Microscopy
- Lesion contains papillae with delicate fibrovascular cores and are lined by tumor cells
- Myoepithelial cell layer will be absent in 90% of these papillary processes
- They can also have solid and cribriform patterns
- Myoepithelial cell layer is absent in papillary process and also for the distended duct in which the lesion is present
- Tumor cells may be small rounded to spindle cells or columnar cells or apocrine cells
- Distinction between papilloma and intraductal papillary carcinoma is difficult and in such cases immunohistochemistry for myoepithelial cells (p63, CD10, Calponin) may be helpful.
- Prognosis is good in the absence of invasive component.