Rosen's Breast Pathology, 4e

379

Ductal Carcinoma In Situ

reported that patients with a preoperative diagnosis of DCIS rendered on needle core biopsy had a reoperative rate of 36% compared with 65% for those patients who did not ( p = 0.0007). Furthermore, it has been suggested that find- ings in needle core biopsies can help in the achievement of negative margins in lumpectomies through the assessment of relative proportion of DCIS in cases of invasive ductal carcinoma. A high proportion of DCIS in the core biopsy specimen have been shown to identify patients at risk of compromised margins in the subsequently performed lumpectomy. 255 Cytologic Diagnosis Fine-needle aspiration (FNA) specimens from DCIS tend to be less cellular than aspirates from invasive carcinomas, and they are more likely to yield insufficient material for FIG. 11.61.  DCIS, needle core biopsy with displaced epi- thelium. A fragment of papillary carcinoma is lodged in fat. This is not invasive carcinoma.

FIG. 11.63.  DCIS, apocrine type in sclerosing adenosis, needle core biopsy. A: Apocrine DCIS ­occupying SA re- sembles invasive carcinoma. B: A section parallel to (A) prepared with the ­immunostain for SMA demonstrating myoepithelial cells around all glandular structures. diagnosis. 256 These circumstances are especially prone to occur when FNA is performed on a nonpalpable abnor- mality detected by mammography. Failure to obtain diag- nostic material by FNA in this setting is an indication for excisional biopsy. FNA cytologic evaluation is not recom- mended for assessment of mammographically detected microcalcifications. 257 When the FNA specimen is diagnostic of carcinoma, the distinction between intraductal and infiltrating ductal carcinoma cannot be made with confidence. 256,258 Corre- lation with the mammogram is useful, but limitations of sampling make it impossible to exclude the presence of in- vasive carcinoma in a region outside the site of the FNA procedure or to exclude microinvasion in the region of the FNA. Findings more likely to be associated with in- traductal than with invasive carcinoma are admixed cy- tologically benign epithelial cells and histiocytes. Invasive carcinoma is more likely to be present if carcinoma cells singly or in groups are intimately mingled with adipose tis- sue, fibrous stroma, or fat cells.

FIG. 11.62.  DCIS, needle core biopsy with scar. Concen- tric layers of collagen probably represent the scar formed at the site of “healed” DCIS. A dilated duct with a thin layer of DCIS is shown on the left .