An Overview of the History and Epidemiology of Ductal Carcinoma In Situ of the Breast

Radiographic features for triple negative ductal carcinoma in situ of the breast

BACKGROUND

Triple negative (TN) breast cancer is characterized as having a high malignancy potential and a poor prognosis. An understanding of the radiological features of TN DCIS will enable the early detection of intractable TN invasive breast cancer.

METHODS

Our cohort of 494 DCIS patients, including 18 TN DCIS cases (3.6%), was diagnosed and treated between January 2006 and November 2009. We reviewed the TN DCIS cases in order to assess mammogram (MMG), ultrasound (US), magnetic resonance imaging (MRI), and pathology findings. Routine diagnostic MMG, US, and MRI were performed before surgery in our institution.

RESULTS

The average age of TN DCIS patients was 54.2 years (40-73). MMG findings were as follows: no abnormal findings (n = 4), masses (n = 3), focal asymmetric density (n = 2), architectural distortion (n = 5), and calcifications (n = 4). US findings included low echoic masses (n = 17) and architectural distortion (n = 4). MRI findings (two patients did not undergo this examination) included mass (n = 6) and non-mass-like enhancements (n = 10). The average lesion measured 3.3 cm in diameter (0.5-8.5 cm). The histological findings were non-comedo type (n = 9) and mixed type including some comedo components (n = 9). Notably, our study revealed that only 22% of TN DCIS cases were detected via mammographic abnormal calcifications. This percentage was less than in non-TN DCIS cases. TN DCIS cases were detected mainly because of masses or asymmetry. US and MRI findings of TN DCIS revealed the same features considered to be common DCIS findings.

CONCLUSION

We diagnosed TN DCIS in 3.6% of our cohort including 494 DCIS patients. Incidences of TN DCIS with mammographic abnormal calcifications were fewer than those of non-TN DCIS cases.

Sonographic findings of high-grade and non-high-grade ductal carcinoma in situ of the breast

OBJECTIVE

The purpose of this study was to differentiate between high-grade and non-high-grade ductal carcinoma in situ (DCIS) of the breast on sonography.

METHODS

From October 2003 to August 2009, 76 DCIS lesions in 73 women who underwent sonography and mammography were included in this study. Lesions were confirmed by mastectomy, breast-conserving surgery, or surgical biopsy. Images were analyzed by 2 radiologists with consensus and were correlated with histologic grades.

RESULTS

Of the 76 lesions, 44 were classified as high--grade and 32 as non-high-grade DCIS. Fifty-seven lesions (75.0%) were identified on sonography, which revealed a mass in 30 cases, microcalcifications in 20, ductal changes in 4, and architectural distortion in 3. All cases with false-negative findings on sonography (n = 19) showed microcalcifications on mammography. On sonography, masses were more frequently found in non-high-grade (62.5%) than high-grade DCIS (22.7%; P < .01). No significant difference was seen in the sonographic features of masses between high-grade and non-high-grade DCIS. Microcalcifications were more common in high-grade (43.2%) than non-high-grade (3.1%) DCIS (P = .02). Most sonographically visible microcalcifications had associated findings such as ductal changes (n = 11), a mass (n = 7), or a hypoechoic area (n = 5). The detection rate of microcalcifications on sonography was higher in high-grade (62.9%) than non-high-grade DCIS (25.0%; P = .023).

CONCLUSIONS

Microcalcifications with associated ductal changes (11 of 31 [35.5%]) were the most common sonographic findings in high-grade DCIS. An irregular hypoechoic mass with an indistinct and microlobulated margin (13 of 26 [50.0%]) was the most frequent finding in non-high-grade DCIS.

Ultrasound findings and histological features of ductal carcinoma in situ detected by ultrasound examination alone

BACKGROUND

With the increasing use of high-resolution ultrasound (US) examination, many breast carcinomas that cannot be identified by mammography (MMG) alone have been detected. Many of these carcinomas are ductal carcinoma in situ (DCIS) and small-sized invasive carcinomas. Until date, DCISs have often been described as palpable masses with calcifications on MMG, but what are the characteristics of DCISs that are detectable by US alone?

METHODS

One hundred fifty cases with DCIS that we experienced at our clinic from 2003 to 2007 were classified into 47 cases (echo group) diagnosed by US alone and 103 cases (MMG/PE group) diagnosed by MMG or clinically.

RESULTS

US findings of the echo group showed cystic or solid lesions in 37 cases (79%). The mean age of the echo group was significantly higher than that of the MMG/PE group (59.6 vs. 51.2 years; P < 0.01). Tumor sizes detected by US were 5.7 + 2.8 and 11.5 + 10.8 mm (P < 0.001), respectively. The tumor sizes of the echo group were, therefore, approximately half that of the MMG/PE group. Extensive intraductal components were significantly fewer in the echo group, and tumor grades of the echo group were significantly low (Van Nuys classification). In the echo group, all cases with a tumor size < 5 mm were grade 1 by Van Nuys classification. In addition, cases with > or = 5 mm tumor size had a significantly lower tumor grade in the echo group than in the MMG/PE group.

CONCLUSIONS

Cystic or solid lesions accounted for approximately 80% of US findings of DCISs detected by US alone, and most were similar to benign forms. Moreover, most DCISs detected by US alone were localized and of low grade (Van Nuys classification).