Metastatic tumors in the breast: a report of 5 cases and review of the literature

PAX8 Expression in Breast Cancer

PAX8 expression is frequently detected in renal, thyroidal, and Müllerian carcinomas, and PAX8 immunohistochemistry is often used to confirm the origin of these tumors. Tumors metastatic to the breast may masquerade as primary breast lesions. PAX8 is strongly expressed in tumors of Müllerian origin and largely negative in breast primaries, but an immunohistochemical expression of PAX8 in breast cancer has not been systematically evaluated in a large series. We analyzed 266 cases of invasive carcinoma of the breast on tissue microarrays and whole tissue sections with a PAX8 monoclonal antibody. Both the extent (focal or diffuse) and intensity (weak, moderate, or strong) of nuclear staining were assessed in the tumor cells. In total, 16 cases (6.02%) were positive for PAX8 (12 with weak and 4 with moderate staining). Expression was diffuse in 7 cases and focal in 9 cases. All 16 PAX8-positive tumors were histologic grade III invasive ductal carcinomas, 13 of these were triple-negative, 2 were HER2-positive, only and 1 was progesterone receptor-positive only. Strong PAX8 nuclear expression was not seen in any of the cases. PAX8 was negative in breast tumors with neuroendocrine features. Our study demonstrated a low rate of PAX8 expression in breast cancer. When present, PAX8 expression was only seen in high-grade invasive ductal carcinomas, mostly triple-negative. The presence of PAX8 immunoreactivity alone cannot exclude mammary origin, especially when only weak to moderate staining is observed, so the correlation with available clinical and pathologic data helps to ensure an accurate diagnosis.

Breast metastasis of gastric signet-ring cell carcinoma

Metastatic breast involvement from extra-mammary neoplasms is unusual with a low incidence of 0.5% to 1.2% in clinical practice, 2.7% in cytological series, and 1.7% to 6.6% in autopsy series of all breast malignancies. Nearly 500 cases have been reported in small series and case reports. Gastric carcinoma rarely metastasizes to the breast. There are only 38 cases reported in PubMed. In this study, we present a case report of a 49-year-old woman who was diagnosed with right breast metastasis from a gastric carcinoma and undertake a literature review to pay attention to the diagnosis, treatment, and the prognosis of the disease.

Clinicopathologic features and treatment of breast metastasis from nasopharyngeal carcinoma: A report of two cases and literature review

Breast metastasis is a rare pattern of distant metastasis from nasopharyngeal carcinoma (NPC) following curative treatment. The present study reported two patients with breast metastasis from NPC and reviewed four such patients reported in the literature, including the analysis of clinical profiles, pathological diagnoses, treatment strategies and outcomes. The breast is a potential metastatic site for patients with NPC following curative treatment; however, thus far, only metachronous breast metastasis has been reported. Infection with Epstein-Barr virus (EBV) was identified in the breast metastasis sites of the two patients investigated in the current study using in situ hybridization for EBV-encoded small RNAs. Patients with breast metastases from NPC consistently and simultaneously develop metastases in other sites. In addition, the two current patients had poor prognoses. Therefore, chemotherapy was the primary treatment strategy administered. A solitary breast metastasis was identified in the male patient. At the most recent follow-up 10 years subsequent to undergoing a Halsted mastectomy, the patient remained alive, however the patient is now lost to follow-up. This case indicates that patients exhibiting NPC with a solitary breast metastasis may still gain long-term survival by undergoing radical mastectomy; therefore, radical mastectomy should be considered in such patients.

Metachronous isolated breast metastasis from pulmonary adenocarcinoma with micropapillary component causing diagnostic challenges

Background

Breast metastasis from extramammary malignancy is uncommon and often presents diagnostic challenges. Herein, we report a case of a patient with metachronous isolated breast metastasis from pulmonary adenocarcinoma with micropapillary component.

Case presentation

A 47-year-old woman presented with left breast nodule detected on a screening breast ultrasonography. She had surgery for pulmonary adenocarcinoma 3 years ago, and was disease-free state in the follow up studies. The patient was diagnosed with invasive micropapillary carcinoma of the breast by core needle biopsy. She underwent left breast lumpectomy and sentinel lymph node biopsy, and the histologic findings revealed micropapillary carcinoma. Based on the immunohistochemical study, the final diagnosis was solitary breast metastasis from pulmonary adenocarcinoma with micropapillary component.

Conclusions

The diagnosis of metastasis to the breast from extramammary malignancies is difficult but important for proper management and prediction of prognosis. A careful clinical history with a thorough clinical examination is needed to make the correct diagnosis.

Characteristics of metastasis in the breast from extramammary malignancies

BACKGROUND AND OBJECTIVE

Breast metastasis from extramammary neoplasm is rare. We present the cases of metastasis to the breast after review of results in one institute and we want to show the difference of previous report.

METHODS

The surgical and pathology databases of Samsung Medical Center from November 1994 to March 2009 were investigated to identify all patients with a diagnosis of metastasis to the breast.

RESULTS

Thirty-three patients with breast metastases from extramammary neoplasm were studied. Gastric carcinoma was most common metastatic origin in this study. There were four cases with microcalcifications in their metastatic lesions. This is the first report of microcalcification of metastatic lesions to the breast from hepatocellular carcinoma and gastric cancer.

CONCLUSIONS

Pathologic examination and considering known clinical history may be helpful to differentiate the primary breast cancer and metastatic cancer. Metastasis to the breast from an extramammary neoplasm usually indicates disseminated metastatic disease and a poor prognosis. An accurate diagnosis of breast metastases, differentiating primary from metastatic breast carcinoma, is important for proper management.