title: Metastatic metaplastic breast carcinoma mimicking pulmonary squamous cell carcinoma on fine-needle aspiration.
abstract: Metaplastic squamous cell carcinoma (SCC) of the breast is a rare type of breast cancer. Metastases to the lung, which can be a major site of second primary tumor development among breast cancer patients, are difficult to distinguish from primary SCC of the lung and present a unique challenge for pathologists. There are few available discriminating immunohistochemical markers as squamous differentiation typically leads to loss of expression of characteristic primary epithelial cell markers of both breast and lung origin. GATA protein binding 3 (GATA-3) is a useful marker of breast origin in metastatic ductal and lobular carcinomas including poorly differentiated triple-negative carcinomas and some metaplastic carcinomas. Here, we present a case of metastatic SCC presenting as a solitary lung mass with regional lymph node metastases and a single satellite lesion in a patient with a history of metaplastic SCC of the breast. In addition to the routine markers of squamous differentiation, the metastases were also positive for estrogen receptor (ER) and GATA-3 on cytologic material obtained by transbronchial FNA. This suggests that immunoreactivity for ER and GATA-3 may support a diagnosis of metastatic SCC in the context of a prior metaplastic SCC of the breast.
authors.affiliation: Department of Pathology, The Johns Hopkins University School of Medicine, Baltimore, Maryland.
authors.forename: Doreen N
authors.initials: DN
authors.lastname: Nguyen
authors.affiliation: Department of Radiology, The Johns Hopkins University School of Medicine, Baltimore, Maryland.
authors.forename: Satomi
authors.initials: S
authors.lastname: Kawamoto
authors.affiliation: Department of Pathology, The Johns Hopkins University School of Medicine, Baltimore, Maryland.
authors.forename: Ashley
authors.initials: A
authors.lastname: Cimino-Mathews
authors.affiliation: Department of Pathology, The Johns Hopkins University School of Medicine, Baltimore, Maryland.
authors.forename: Peter B
authors.initials: PB
authors.lastname: Illei
authors.affiliation: Department of Pathology, The Johns Hopkins University School of Medicine, Baltimore, Maryland.|Department of Oncology, The Johns Hopkins University School of Medicine, Baltimore, Maryland.|Department of Gynecology, The Johns Hopkins University School of Medicine, Baltimore, Maryland.
authors.forename: Dorothy L
authors.initials: DL
authors.lastname: Rosenthal
authors.affiliation: Department of Pathology, The Johns Hopkins University School of Medicine, Baltimore, Maryland.
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: VandenBussche
mesh_terms: D001741:Black or African American; D014408:Biomarkers, Tumor / Q000378:metabolism; D044963:Biopsy, Fine-Needle; D001940:Breast / Q000166:cytology / Q000473:pathology; D001943:Breast Neoplasms / Q000175:diagnosis* / Q000473:pathology; D002294:Carcinoma, Squamous Cell / Q000175:diagnosis* / Q000473:pathology; D003937:Diagnosis, Differential; D005260:Female; D050990:GATA3 Transcription Factor / Q000276:immunology / Q000378:metabolism*; D006801:Humans; D008175:Lung Neoplasms / Q000175:diagnosis* / Q000473:pathology; D008207:Lymphatic Metastasis / Q000175:diagnosis / Q000473:pathology; D008679:Metaplasia / Q000473:pathology*; D008875:Middle Aged; D016609:Neoplasms, Second Primary / Q000175:diagnosis / Q000473:pathology; D011960:Receptors, Estrogen / Q000276:immunology / Q000378:metabolism
chemical_list: D014408:Biomarkers, Tumor; D050990:GATA3 Transcription Factor; C494749:GATA3 protein, human; D011960:Receptors, Estrogen
keywords: GATA-3; breast; cancer; fine-needle aspiration; lung; squamous cell carcinoma