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Chapter 11

B

A

FIG. 11.39.  DCIS in sclerosing adenosis in a needle core biopsy. A: DCIS occupies the structure of SA. Groups of carcinoma cells resemble invasive carcinoma cells. Immu- nostains for SMM-HC (B) and SMA (C) on sections parallel to (A) reveal myoepithelial cells enveloping the groups of carcinoma cells.

C

for predicting the risk of breast recurrence after conserva- tion therapy. When there is an invasive element associated with DCIS, both components tend to have similar nuclear grades. 149 Grading schemes consisting of two categories (high grade and all others) and three categories (high, inter- mediate, and low) have been devised for DCIS. The deter- mination of grade is based upon nuclear cytology 150 and the growth pattern. Nuclear grade tends to be relatively constant in a given patient, even when there is substantial variation in architectural pattern. 149 The presence or absence of necrosis may also be considered in grading. In past decades, DCIS was routinely classified as being of “comedo” or “noncomedo” types. In general, “comedo” carcinoma implied solid type of DCIS with pleomorphic cells bearing high-grade nuclei associated with abundant central necrosis. The term “comedo” referred to necrotic cellular debris that oozed from the cut surfaces of affected ducts when the excised tumor was compressed (i.e., resem- bling the “comedones” in acne vulgaris). The collective term “noncomedo” DCIS in the premammographic era implied all other types of DCIS. These noncomedo DCIS were rarer,

DCIS. Coexistent in situ lesions have been found in asso- ciation with invasive duct and invasive lobular carcinoma. This pattern of in situ carcinoma should be distinguished from lobular extension of DCIS, so-called lobular cancer- ization. In the latter condition, the nonneoplastic lobular epithelium is displaced by carcinoma cells with the same cytologic appearance as the DCIS. As outlined earlier, the E-cadherin stain, among others, can be used to identify LCIS in DCIS. Computerized image analysis systems for classifying various noninvasive proliferative and neoplastic lesions on digitized slides are in development, and at this time they have more potential as an educational tool rather than as a stand-alone diagnostic tool. 146 Grading of DCIS The interval between DCIS and the development of invasive carcinoma is shorter for high-grade DCIS, averaging 5 years, than for low-grade DCIS, which takes a mean period of more than 15 years. 147,148 Grading of DCIS can also be useful