title: Breast cancer or metastasis? An unusual case of metastatic malignant pleural mesothelioma to the breast.
abstract: BACKGROUND
  Metastases to the breast from extramammary malignancies are very rare, and ruling out the diagnosis of primary breast tumor is important in order to decide on clinical management and predict prognosis.
  
  
  METHODS
  Clinical examination revealed in a 49-year-old hairdresser a 3-cm hard lump adherent to the underlying layers in the right breast. Trucut biopsy was performed. Histology showed a solid proliferation of medium-sized neoplastic polygonal cells. Immunohistochemical analysis showed tumor cells diffusely positive for cytokeratin 8/18 and calretinin and focally positive for cytokeratin 5/6 and Wilms' tumor 1, e-cadherin, and human bone marrow endothelial-1. Estrogen receptors and progesterone receptors were negative. The final diagnosis was metastatic epithelioid malignant pleural mesothelioma.
  
  
  CONCLUSIONS
  Immunohistochemistry is an important tool for a conclusive diagnosis of malignant pleural mesothelioma. Owing to the degree of histological and immunohistochemical overlap, a high level of clinical suspicion is essential in order to avoid unnecessary mutilating surgery.
authors: Marialuisa
authors: M
authors: Framarino-dei-Malatesta
authors: Paolo
authors: P
authors: Sammartino
authors: Martina
authors: M
authors: Derme
authors: Isabella
authors: I
authors: Iannini
authors: Gabriele
authors: G
authors: Masselli
authors: Irene
authors: I
authors: Pecorella
mesh_terms: D014408:Biomarkers, Tumor / Q000378:metabolism*; D001943:Breast Neoplasms / Q000175:diagnosis* / Q000378:metabolism; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007124:Immunoenzyme Techniques; D008175:Lung Neoplasms / Q000175:diagnosis* / Q000378:metabolism; D008654:Mesothelioma / Q000175:diagnosis* / Q000378:metabolism; D000086002:Mesothelioma, Malignant; D008875:Middle Aged; D010997:Pleural Neoplasms / Q000175:diagnosis* / Q000378:metabolism; D011379:Prognosis
chemical_list: D014408:Biomarkers, Tumor