A MEDICAL SERVICES PROVIDER
                     "people caring for people"

Case of the Month




Encapsulated papillary carcinoma

August, 2020

This 84 year old woman underwent mastectomy for a “Papillary neoplasm”. The mastectomy specimen demonstrated a 2.0 cm well circumscribed cystic lesion filled with a shaggy pink/tan tumor. Histologic sections show an encapsulated papillary neoplasm with delicate fibrovascular cores. Myoepithelial cells are not seen at the periphery of the tumor or within the papillae with P63 and Calponin immunoperoxidase stains. Adjacent to the papillary neoplasm is a focus of low grade cribriform ductal carcinoma in situ (DCIS). Submitted lymph nodes show a focus of metastatic tumor (micrometastasis).  The histologic findings support a diagnosis of Encapsulated Papillary Carcinoma (Encysted Papillary Carcinoma/Intracystic Papillary Carcinoma).

Encapsulated papillary carcinoma comprises approximately 0.5 to 2% of a breast carcinomas and occurs most often in elderly women with a median age of 70 years. The clinical behavior is similar to DCIS and the WHO recommends classifying this tumor as DCIS.  However, since there is an absence of myoepithelial cells around these type of tumors, some investigators think this tumor is an indolent form of invasive carcinoma with an expansile growth pattern.  Although these tumors typically don’t metastasize to lymph nodes, rare cases have been reported with tumor metastasizing to lymph nodes, which is present in this case.