An Improved Computer-aided Diagnosis Scheme Using the Nearest Neighbor Criterion for Determining Histological Classification of Clustered Microcalcifications

Summary Objectives : Our purpose was to evaluate the potential usefulness of the nearest neighbor case which was assumed to be the similar case in a CAD scheme for determining the histological classification of clustered microcalcifications. Methods : Our database consisted of current and previous magnification mammograms obtained from 93 patients before and after three-month follow-up examination. It included 11 invasive carcinomas, 19 noninvasive carcinomas of the comedo type, 25 noninvasive carcinomas of the noncomedo type, 23 mas- topathies, and 15 fibroadenomas. Six objective features on clustered microcalcifications were first extracted from each of the current and the previous images. The nearest neighbor case was then identified by the Euclidean distance in the previous and current feature-space. The histological classification of an unknown new case in question was assumed to be thesame as that of the nearest neighbor case which has the shortest Euclidean distance in our database. Results : The classification accuracies were 90.9% for invasive carcinoma, 89.5% for noninvasive carcinoma of the comedo type, 96.0% for noninvasive carcinoma of the noncomedo type, 82.6% for mastopathy, and 93.3% for fibroadenoma. These results were substantially higher than those with our previous CAD scheme. Conclusion : The nearest neighbor criterion was useful in a CAD scheme for determining the histological classification.

Noninvasive Carcinoma of the Breast: Angiogenesis and Cell Proliferation

Context.—Angiogenesis and the cell proliferation index can predict the prognosis of invasive breast carcinoma; however, little is known of their roles in noninvasive tumor. Objective.—To investigate the correlation of microvessel density and cell proliferation index with other histologic parameters (histologic type, nuclear grade, and mitotic count) in 65 cases of noninvasive carcinoma of the breast. Design.—Formalin-fixed, paraffin-embedded tissues from 65 cases of carcinoma in situ of the breast were immunostained with antibody against factor VIII antigen and proliferation-associated nuclear antigen MIB-1. The microvessel density was measured by counting the total number of microvessels around the carcinoma in situ per 10 low-power microscopic fields. The cell proliferation index was calculated by counting MIB-1–positive nuclei in 100 tumor cells. A χ2 test and Spearman rank correlation test were used for statistical analysis. Results.—The microvessel density and cell proliferation index of comedo-type, high-nuclear-grade ductal carcinomas in situ are significantly higher than those of either noncomedo type ductal carcinomas in situ or lobular carcinoma in situ (P < .001). Conclusions.—Angiogenesis and the cell proliferation index are active biological processes and may be considered as markers to separate low- and high-risk patients with noninvasive breast carcinomas.

Stereotaxic core needle aspiration biopsy with multiple passes in nonpalpable breast lesions

Objective: To compare the grade of histologic agreement between stereotaxic core needle aspiration biopsy (SCNAB) with multiple passes, and surgical excision. Methods: A total of 180 patients with 182 nonpalpable breast lesions underwent SCNAB with multiple passes in an upright add-on stereotaxic device using a manual 1.8-mm needle (15 G). In this group, 125 patients underwent subsequent surgical excision. Results: A SCNAB result indicative of malignancy (invasive or noninvasive carcinoma) was obtained in 68 (87%) of the 78 breast carcinomas (14 noninvasive and 64 invasive) and definitive surgical therapy with a one-stage procedure was performed. Complete or partial agreement between core biopsy and surgery was observed in 19 (86%) of 22 invasive or noninvasive carcinomas discovered by microcalcifications, 40 (97.5%) of 41 invasive carcinomas discovered by a mass, and 9 (60%) of 15 invasive or noninvasive carcinomas discovered by architectural distortion. Six (33%) of the 18 patients whose core biopsies showed noninvasive carcinoma had an invasive or microinvasive component at subsequent surgery. Atypical hyperplasia or benign core biopsy was observed in 6 (8%) and 4 (5%) breast carcinomas respectively. Conclusion: SCNAB with multiple passes is a reliable method for identifying nonpalpable lesions in patients with noninvasive or invasive carcinomas discovered by respectively microcalcifications or mass.