Rosen's Breast Pathology, 4e

901

Unusual Clinical Presentation of Carcinoma

FIG. 33.4.  Fibroadenoma, intraductal carcinoma. A,B: The usual epithelium in these two different sclerotic fibroadenomas has been replaced by high-grade DCIS.

frequent than DCIS (Fig. 33.8). Infiltrating duct carcinomas (Fig. 33.9) have also been described. 101,102,113–116 An IDC aris­ ing in a low-grade malignant PT in a 24-year-old woman was the source of isolated tumor cells in an ipsilateral SLN. 117 ­Korula et al. 118 described a 51-year-old woman who had DCIS in and around an malignant PT. Lymphatic tumor emboli were found in the PT, and metastatic carcinoma was present in two ALNs, but no invasive tumor was detected in the PT or in the breast. Microinvasive and ILC can also be found in this setting. 119 A high-grade malignant PT that con­ tains carcinoma is a form of carcinosarcoma , because these lesions are, by definition, neoplasms that combine carcino­ matous and sarcomatous elements derived from the mam­ mary ­epithelium and stroma. Carcinoma has been found in the surrounding breast tissue concurrently with, or subse­ quent to, excision of a PT that contained carcinoma. 102,120,121 Well-differentiated infiltrating duct carcinoma 122 and tubular carcinoma 115,123 have been described in PT. The latter case was unusual in that tubular carcinoma was found in the second recurrence of a benign PT. The first recurrence con­ tained LCIS. In the case reported by ­Quinlan-Davidson, 115 LCIS and tubular carcinoma coexisted in a low-grade malignant PT. Other unusual pathologic presentations have been coex­ istent DCIS and LCIS in a benign PT, 124 invasive carcinoma with ductal, secretory, and squamous components, 125 infil­ trating duct carcinoma coincidental with but separate from benign PT 102 and malignant PT, 126 LCIS in a PT with liposar­ comatous stroma, 127 and microinvasive lobular carcinoma in a benign PT. 119 PT that harbor carcinoma are usually benign or low-grade malignant tumors, whereas carcinoma is more often found in breast tissue outside an malignant PT. 114,121 There are rare instances of PT with carcinoma that devel­ oped after treatment for another malignant neoplasm. Aziz et al. 121 described a 43-year-old woman who had carcinoma in a malignant liposarcomatous PT. Approximately 20 years earlier she had received chemotherapy for Hodgkin disease and radiotherapy to the lumbar region. Another woman who developed a liposarcomatous and chondrosarcomatous

malignant PT associated with carcinoma when 26 years old had been treated by surgery and chemotherapy without radiotherapy for tibial osteosarcoma 11 years earlier. 120

Molecular Analysis Macher-Goeppinger et al. 128 described the results of the mo­ lecular analysis of an IDC within an malignant PT. DNA was isolated from the microdissected epithelial and stromal components of the PT, and from the high-grade IDC. Using the multiplex polymerase chain reaction (PCR), compara­ tive allelotyping was performed with a panel of 11 microsat­ ellite markers. Analysis of the data revealed that the stromal component of the PT showed loss of heterozygosity (LOH) at chromosome 16q23, 17q12, 17q25, and 22q13 and that the epithelial element of the tumor shared the loss of 16q23. The invasive carcinoma had lost divergent alleles at 16q23, 17q12, and 17q25. These findings were interpreted as dem­ onstrating a lack of clonality between the malignant PT and the invasive carcinoma that arose within it. Treatment and Prognosis There have been very few deaths due to carcinoma arising in a FA, and these have been attributable to IDCs. 101,104 Recurrence in the breast following excisional biopsy of a FA that harbored in situ lobular or intraductal carcinoma has been uncommon and appears to be less frequent than when the same lesions that occur outside of FA have been treated only by excisional sur­ gery. 99 There are virtually no published data on breast conserva­ tion therapy that employed radiation in addition to ­excisional surgery to treat intraductal carcinoma in a FA. The low fre­ quency of subsequent carcinomas may reflect to some extent the relatively short follow-up, averaging less than 10 years, in most series of patients with carcinoma arising in a FA. There are no systematic data on the treatment and prog­ nosis of women who had carcinoma arising in a PT. The need to ensure adequate excision of the PT in some cases