Breast metastases from primary lung cancer: a retrospective case series on clinical, ultrasonographic, and immunohistochemical features

Abstract

Background: Lung cancer metastases to the breast are less common and consequently have received much less attention in clinical practice. The purpose of this study was to provide a better understanding of clinical, ultrasonographic, and immunohistochemical features of breast metastases from primary lung cancer.Methods: This retrospective case series included patients with breast metastases from primary lung cancer between January 2012 and December 2020. Clinical features, ultrasonographic characteristics, and immunohistochemical findings were evaluated in this analysis.Results: In all, 7 cases (mean ± standard deviation age: 57.4±8.3 years; range, 49-70 years) were evaluated. The maximum size of breast lesions in 6 cases ranged from 1.2 to 4.5 cm, while 1 case showed a diffused pattern. Ultrasound features of breast metastases from lung cancer were irregular (5/7, 71.4%), indistinct (6/7, 85.7%), hypoechoic (7/7, 100.0%), and parallel (6/7, 85.7%) masses without calcification.Immunohistochemical staining test was positive for thyroid transcription factor 1 (TTF-1) in all patients (7/7, 100.0%), 3 cases (3/5, 60.0%) were negative for p63, 5 cases (5/5, 100.0%) were positive for cytokeratin 7 (CK7), 4 cases (4/5, 80.0%) were positive for napsin A. Conclusions:The ultrasonographic features of lung metastases to the breast are clinically important to understand. A known history of the primary lung cancer is of great importance when evaluating patients with a breast nodule. The presence of an ipsilateral lung cancer, breast nodule and axillary lymphadenopathy should be considered with pathological and immunohistochemical data to differentiate breast metastases from a primary breast malignancy in this setting.

Lung cancer with breast metastasis: a case report and review of the literature

“…18 In contrast, ER, PR, HER2, and GATA3 are commonly used to identify breast cancer. 15 Our patient had a long disease course, and the presence of a breast mass was first noticed 3 years prior to presentation. The patient had minimal symptoms during the 3-year period, and the mass changed very little after it was first noticed.…”

“…Therefore, the differential diagnosis of primary and metastatic tumors typically relies on immunohistochemistry. 15 TTF-1 is expressed in 70% to 80% of all small cell carcinomas and adenocarcinomas but not in other types of lung cancer. 15,17 TTF-1 has been used as a marker to determine the origin of metastatic masses in lung cancer.…”

“… 13 , 14 Ultrasonography of metastatic breast tumors of lung cancer often shows a round or oval mass with homogeneous or heterogeneous hypoechogenicity, indistinct margins, and no calcification. 13 – 15 Most metastatic lesions have low signal intensity on T1-weighted sequences and medium signal intensity on T2-weighted sequences with magnetic resonance imaging. 14 Instant and homogeneous enhancement can be observed with contrast agents.…”

Primary lung adenocarcinoma with breast metastasis harboring the EML4‑ALK fusion: A case report

“…Of note, there are certain differences between the present case and previously reported cases. First, Wang et al ( 23 ) integrated data of 7 patients with primary lung cancer breast metastasis and proposed that the combination of TTF-1 and Napsin-A can provide the greatest benefit in clinical practice, suggesting that metastatic breast nodules typically present unilaterally without pain. Ji et al ( 24 ) reported two cases of lung adenocarcinoma breast metastasis in which the diagnosis primarily relied on medical history and IHC results, and both patients had a history of lung cancer.…”

Breast metastasis of a lung carcinoma

“…The common ultrasound features of breast metastasis from lung cancer are irregular, hypoechoic and parallel masses without posterior enhancement. 3 The atypical feature for a benign lesion such as fibroadenoma was the numerous microlobulations. 4…”