[190] Neuroendocrine Tumors (NETs) Account for 44% of Breast Cancers Detected by the Clinical Symptom of Bloody Nipple Discharge.

Tomonori Kawasaki, Tetsuo Kondo, Hideko Yamauchi, Tetsu Yamane, Tadao Nakazawa, Kunio Mochizuki, Yoshio Ishii, Hiroshi Yagata, Hiroko Tsunoda, Seigo Nakamura, Takanori Maruyama, Ayako Inoue, Masayuki Inoue, Shingo Inoue, Koji Kono, Hideki Fujii, Ryohei Katoh. University of Yamanashi, Japan; St. Luke's International Hospital, Tokyo, Japan

Background: Neuroendocrine ductal carcinoma in situ (NE-DCIS) of the breast has characteristic clinicopathological features such as bloody nipple discharge (BND) (72%), a low frequency of preoperative diagnosis (67%) and low-grade pathological parameters, and can, therefore, be regarded as a distinct variant of DCIS. In our study, we investigated the association between the clinical symptom of BND and neuroendocrine tumors (NETs) of the breast.
Design: We studied 144 patients with BND out of 315 patients who came to the hospital for a thorough examination of symptomatic nipple discharge. Of these 144 patients with BND, 89 (62%) were histopathologically examined and 55 (38%) were followed with periodic diagnostic imaging such as ultrasonography and mammography.
Results: Of the 89 cases examined histologically, the pathological diagnosis was carcinoma in 55 cases (62%), intraductal papilloma in 18 cases (20%) and benign lesions including fibro-cystic disease in 16 cases (18%). Among the 55 carcinomas, 24 cases (44%) were diagnosed as a NET in which >50% of cells immunohistochemically expressed specific NE markers (chromogranin A and/or synaptophysin). In addition, NETs made up 17% (24/144) of all the cases having BND. These 24 NETs were subclassified into NE-DCIS (9 cases, 38%), microinvasive NET (7 cases, 29%) and solid NE carcinoma (8 cases, 33%). All the solid NE carcinomas had an extensive intraductal (NE-DCIS) component and were classified into pT1a (5 cases), pT1b (1 case), pT1c (1 case) or pT2 (1 case) according to the 2002 TNM Staging Classification of Breast Carcinomas. All 24 NETs were of low to occasionally intermediate nuclear and/or histological grades, had diffuse and strong immuno-reactivity for estrogen and/or progesterone receptors and negativity for HER2 (i.e. so-called luminal A subtype). Axillary lymph node metastasis was identified in only one case (4%) with micrometastasis in a sentinel lymph node.
Conclusions: Breast NETs (NE-DCISs and invasive NETs with an extensive NE-DCIS component) accounted for a large share of cancers detected in patients having BND. NE-DCIS tends to be under-diagnosed preoperatively and, thus, a better understanding of its clinicopathological features may lead to more early detections of NETs of the breast.
Category: Breast

Monday, February 28, 2011 1:00 PM

Poster Session II # 46, Monday Afternoon


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