Clinical Outcome of Intracystic and Solid Papillary Carcinomas of the Breast
Roberto G Gamez, Sonia Narendra, Aziza Nassar. Mayo Clinic, Rochester, MN
Background: Papillary carcinoma (PC) of the breast accounts for 0.5 to 1% of breast cancer. The localized form of PC encompasses both the intracystic/encysted (IPC) and solid (SPC) variants, which are typically circumscribed and often encapsulated (separated from the surrounding mammary stroma by a fibrous capsule) and lack myoepithelial layer at their periphery. Hence the term encapsulated PC (EPC) has been introduced. IPC is usually confined to a dilated cystic space and is surrounded by a fibrous capsule. Compared to IPC, SPC is typically solid, characterized by mucin production and neuroendocrine features, and is more often multinodular. IPC and SPD have long been regarded as a form of in-situ carcinoma but the observation of the absence of a myoepithelial cells at the tumor stromal interface has led to the proposal that these lesions are, in fact, invasive carcinomas with an expansile growth pattern. This concept is supported by the results of some studies which reported cases of axillary nodal or distant metastases. The purpose of our study is to assess the clinical features, behavior and outcome of IPC and SPC in our population in regards to its clinical outcome in order to better understand the pathophysiology of these lesions.
Design: All cases of IPC and SPC were retrieved using SnoMed search from 1994 to 2011. The clinical-pathologic features including post-surgical treatment and outcome (recurrence, metastasis and death) were investigated and recorded. Descriptive and inferential analysis was performed.
Results: See Table 1.
|Variables||IPC (21)||SPC (12)|
|Median age (mean)||68.7 (70.3)||72.2 (69.9)|
|Histologic grade||100 % low grade||91.7% low grade, 8.3% immediate grade|
|Mean tumor size (range)||1.4 cm (0.5- 2.5 cm)||1.8 cm (0.6 - 4.3)|
|Associated DCIS||38.1% (8/21)||25%(3/12)|
|Invasive ductal carcinoma IDC||33.3% (7/21)||50.0% (6/12)|
|Lymph node (LN) status (positive)||0.09% (1/11)||0.12% (1/8)|
|Mean folow up time (years)||4.2 (0-11)||1.5 (0.1-5.4)|
|Metastasis or death of disease||None||None|