Abstract. Nine cases of infiltrating cribriform carcinoma (ICC) of the breast are reported and the clinicopathological features, particularly the imaging findings, are analyzed in the present study. Sonograms revealed that all masses exhibited a hypoechoic internal echo texture (9/9) and that a number of masses presented with an irregular shape (8/9), obscure boundary (5/9), partially microlobulated (5/9) or well-circumscribed (4/9) margins, and an inhomogeneous echo (8/9). Mammographic imaging revealed increased radiological density masses (6/8), and sand-like calcification was not observed in all patients. In two patients, the tumors were mammographically occult. Magnetic resonance imaging performed on one patient revealed a slightly high signal intensity on fat-saturated T1-and T2-weighted images. Following contrast enhancement, a homogeneous early enhancement was revealed with a quick ascent and quick descent time-density curve. Immunohistochemistry revealed that all ICCs expressed estrogen receptor and progesterone receptor, but that none were positive for human epidermal growth factor receptor 2. The Ki-67 labeling index was 3.75% (range, 2-5%) in the tumor tissue. Four patients were treated with mastectomy and the others with breast-conserving surgery. Six clinically node-negative patients underwent sentinel lymph node biopsy; three then received axillary lymph node dissection. Following surgery, three patients received adjuvant chemotherapy, radiotherapy and hormonal therapy, respectively. With a median follow-up time of 38 months (range, 4-70 months), one patient developed local recurrence following breast-conserving surgery; axillary lymph nodes and distant metastases were not observed. This study confirms that this type of carcinoma has unique biological characteristics and a favorable prognosis, but that it remains possible to experience local recurrence.
IntroductionInfiltrating cribriform carcinoma (ICC) of the breast, which is characterized by a predominant cribriform growth pattern of its invasive component, is a distinct histological type of invasive carcinoma first described by Page et al in 1983 (1). The incidence of ICC is reported to range from 0.3 to 3.5% (1-4). The carcinoma has a low frequency of axillary nodal metastases and a favorable prognosis (2). Previous immunohistochemical studies (2,5-7)have revealed that the majority of patients with ICC exhibited estrogen receptor (ER) and progesterone receptor (PR) positive tumors, while human epidermal growth factor receptor 2 (HER2) amplification was rarely observed (5). For this reason, some people recommended that this favorable histotype with luminal tumor may be suitable for no therapy or endocrine therapy alone (8). However, no standard treatment guidelines exist for ICC and thus, treatment is mostly based on that for invasive ductal carcinoma (IDC). Clinically, the tumor usually presents as a mass, but is frequently asymptomatic. The tumor is not usually detected by mammography, but may be identified as a non-malignant mass on sonograp...
