Rosen's Breast Pathology, 4e

905

Unusual Clinical Presentation of Carcinoma

for contralateral breast carcinoma 129,131 or developed subse­ quent carcinoma in the contralateral breast. 129,132 One patient had an augmentation prosthesis in the breast that harbored a subclinical carcinoma. 129 Huston et al. 155 studied seven women who developed contralateral axillary nodal metastases. The median interval between treatment of the initial carcinoma and subsequent contralateral axillary metastases was 71 months. All had adjuvant chemotherapy and five underwent axillary dissection. There were no axillary recurrences after a median follow-up of 35 months, at which time five women were alive, two with recurrent carcinoma, and two had died of metastatic carcinoma. It is possible that the prior contralateral carcinoma is the source of axillary metastases in many of these situations, but in some instances an occult primary may give rise to the newly apparent nodal metastases. 139 Clonal analysis may be employed to evaluate metastatic carcinoma in contralateral ALNs if material from the ipsi­ lateral tumor is available for comparison. In the majority of cases, clonal analysis of the carcinomas in both breasts of patients with bilateral tumors has demonstrated cyto­ genetic differences indicative of independent origin of the lesions. 156,157 Rarely, the pattern of the clonal abnormalities in both tumors suggests metastatic spread from one breast to the other. 157 A similar conclusion would be supported by finding that a primary carcinoma and a metastatic tumor at another site such as the chest wall or contralateral ALNs shared the same karyotypic abnormalities. 156 FIG. 33.9.  Phyllodes tumor, benign, with intraductal and invasive ductal carcinoma. A,B: Cribriform intraductal car- cinoma is next to IDC. C: Isolated cells ( arrows ) of IDC are highlighted by a CK immunostain in a benign PT. Glandular components of the PT are also cytokeratin positive (CK7).

in pooled results from 10 studies published until 2008. 148 In another pooled study published in 2010, the specificity of MRI was 31% on pooled data (range, 22% to 50%) from seven studies. 149 However, not all lesions detected by MRI in this setting prove to be carcinoma. Buchanan et al. 136 re­ ported false-positive MRI studies in 15 of 69 patients, and in another series, MRI yielded a false-positive result in 2 of 15 cases. 150 The diagnostic yield is low in patients with a neg­ ative mammogram and a negative MRI, 136 a situation that led the European Society of Breast Cancer Specialists to recom­ mend that surgical treatment be avoided if MRI of the breast is negative. 148 Positive MRI findings should be investigated by biopsy. In a high proportion of cases, lesions detected by mammography can be localized by sonography, making them amenable to sonographically directed needle core biopsy. 151 Occasionally, nodal enlargement occurs in the contralat­ eral axilla of a patient treated previously for mammary car­ cinoma. 139,152 This phenomenon was observed in 52 (3.6%) of 1,440 patients in one series. 153 Most of these patients were judged to have systemic disease. Six of the 52 patients (0.04%) were treated by contralateral mastectomy, and 2 had a primary tumor in the contralateral breast. Breslow 154 reported that 6 (0.39%) of 1,543 patients with unilateral breast carcinoma sub­ sequently developed carcinoma in contralateral ALNs, and that a primary tumor was detected in four of the opposite breasts. In a series of patients presenting with axillary metastases from subclinical breast carcinoma, about 8%were previously treated