Low-Grade Ductal Carcinoma In Situ.

OBJECTIVES: We aimed to determine the interobserver reproducibility in diagnosing low-grade ductal carcinoma in situ (DCIS). We also aimed to compare the interobserver variability using a proposed two-tiered grading system as opposed to the current three-tiered system. METHODS: Three expert breast pathologists and one junior pathologist identified low-grade DCIS from a set of 300 DCIS slides. Months later, participants were asked to grade the 300 cases using the standard three-tiered system. RESULTS: Using the two-tiered system, interobserver agreement among breast pathologists was considered moderate (κ = 0.575). The agreement was similar (κ = 0.532) with the junior pathologist included. Using the three-tiered system, pathologists' agreement was poor (κ = 0.235). CONCLUSIONS: Pathologists' reproducibility on diagnosing low-grade DCIS showed moderate agreement. Experience does not seem to influence reproducibility. Our proposed two-tiered system of low vs nonlow grade, where the intermediate grade is grouped in the nonlow category has shown improved concordance.

Serous carcinoma of the ovary and peritoneum with metastases to the breast and axillary lymph nodes: a potential pitfall.

Metastasis of ovarian or peritoneal serous carcinoma to the breast and/or axillary lymph nodes is a rare event. Nevertheless, its recognition and distinction from mammary carcinoma are of great clinical importance because the treatment and prognosis differ significantly. Eighteen cases of ovarian or peritoneal serous carcinoma metastatic to the breast and/or axillary LNs from a 14-year period (1990-2003) were retrieved from our files. Clinical information was obtained from the patients' charts. The age of the patients ranged from 21 to 67 years (median, 55 years). The primary tumors included 14 ovarian serous carcinomas (11 high grade and 3 low grade; 2 of the low-grade tumors presented as serous tumors of low malignant potential and recurred as low-grade serous carcinoma) and 4 peritoneal serous carcinomas (3 high grade and 1 low grade). Of the ovarian neoplasms, 1 was stage I and 10 were stage III tumors; the breast and/or axillary lymph node metastases were discovered on average 30 months after presentation (range, 7-135 months). Three of the ovarian serous carcinomas were stage IV tumors; in 1 case, there were axillary lymph node metastases at initial presentation; and in 2 cases, breast and/or axillary lymph node metastases developed at 18 and 102 months. Two of the 4 patients with peritoneal serous carcinoma presented with stage IV disease, having synchronous breast and axillary lymph node metastases; the other 2 patients developed them at 11 and 16 months after presentation. Four patients had multiple breast lesions and 8 patients had a single metastasis. In 4 cases, the breast metastases were initially interpreted as infiltrating ductal carcinoma. The remaining 6 patients had axillary lymph node involvement only. The metastases in 17 of the cases had papillary features, with psammoma bodies present in 4. Immunoperoxidase studies for GCDFP-15 and WT-1 were performed in 4 cases; all 4 were positive for WT-1 and negative for GCDFP-15. Follow-up was available for 17 patients, with 7 patients known to be dead from disease (survival range, 2-31 months) after the development of metastatic disease to the breast or axillary lymph nodes. Ten patients were alive with disease at their last follow-up, which ranged from 1 to 30 months after the breast or axillary LN metastasis developed. Metastases to the breast or axillary lymph nodes from ovarian and/or peritoneal serous carcinomas are uncommon. Most of the patients in whom metastatic disease develops have a known history of advanced stage ovarian or peritoneal carcinoma. Breast and/or axillary LN involvement at initial presentation can occur but is rare. Differentiation between metastatic and primary tumors of the breast is of great importance because treatment and prognosis differ significantly. Clinical history, the presence of papillary architecture, and WT-1 expression are useful in establishing the correct diagnosis.

Large-needle core biopsy in atypical intraductal epithelial hyperplasia including immunohistochemical expression of high molecular weight cytokeratin: analysis of results of a single institution.

The diagnosis of atypical intraductal epithelial hyperplasia (AIDH) constitutes 6.3% of the breast core biopsies performed at our institution. Seventy-nine cases that were diagnosed as AIDH on core biopsy and went through excisional biopsy were included. Sixty-four biopsies were performed by an image-guided 11-gauge vacuum device, 11 under sonographic guidance using 14-gauge needles and 4 by a sonographically guided 11-gauge vacuum device. The histopathology of the core biopsies and the surgical excisions were reviewed. Immunohistochemistry was performed on the consecutive sections of core biopsy specimens using high molecular weight cytokeratin (HMW-CK) (DAKO-Cytokeratin, 34betaE12). At interpretation of the stain, intensity and percentage of positive cells were taken into account. The immunoprofiles of AIDH were categorized into four groups showing negative (i.e., no staining) or low-, moderate-, high-, and very high-intensity staining. Surgical excision of the 79 lesions revealed carcinoma in only 3 cases (4%)-two infiltrating carcinomas and one intraductal carcinoma-residual AIDH in 44 cases (56%), and epithelial hyperplasia or other benign lesions without atypia in 32 cases (40%). The HMW-CK stain was performed retrospectively on all of the core biopsies and 66 of them contained residual areas with AIDH for staining. Forty-nine (74%) were CK negative or stained with low intensity, but 17 cases (26%) had a moderate- to high-intensity stain. Our study showed a lower incidence of carcinoma on surgical excision following core biopsy for AIDH than other studies. The HMW-CK stain helped to characterize the nature of the intraductal proliferation and to confirm the presence of atypia, as has been previously reported, but frequently was inconclusive. The low incidence of carcinoma brings into question the need for surgical excision of all cases of AIDH diagnosed by core biopsy.