Rosen's Breast Pathology, 4e

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Chapter 11

FIG. 11.7.  DCIS, clear cell. A: Solid carcinoma with necrosis and calcification. B,C: Intermediate nuclear grade in DCIS. D–E: Micropapillary and cribriform DCIS. Note apocrine- type cytoplasmic features in some cells. case. Some combinations of growth patterns and cytologic appearances occur more frequently, such as classic comedo DCIS composed of poorly differentiated pleomorphic cells or the low nuclear grade typically present in micropapillary DCIS. Heterogeneity is illustrated by lesions composed of small, cytologically low-grade nuclei growing in a solid pat- tern or by high-grade nuclei found in some examples of mi- cropapillary DCIS (Fig. 11.9). The presence of two or more structural patterns that have different cytologic features is particularly unusual (Fig. 11.10). Classification schemes de- veloped to take cognizance of the heterogeneous distribu- tion of nuclear grade and necrosis across the spectrum of

approximately 50% of cases. Whereas some structural com- binations, such as papillary– or micropapillary–cribriform and solid-comedo, occur relatively more often than others, there is considerable heterogeneity with respect to growth patterns. 115 The probability of structural variability increases with the size of the lesion. Needle core biopsy samples may not be representative of the diverse growth patterns in a single case. The histologic diagnosis of DCIS should list the structural types in order of decreasing prominence, placing the dominant pattern first. Cytologic features, especially at the nuclear level, tend to be more homogeneous than the growth pattern in a given