title: Morphological features and mucin expression profile of breast carcinomas with signet-ring cell differentiation.
abstract: Signet-ring cells are relatively common in breast cancers but are frequently overlooked. Although previously defined as a subtype of mucin producing carcinomas, breast carcinomas with signet-ring cell (SRC) differentiation nowadays are not considered a distinct entity. The objective of the present study was to characterize the morphological features and mucin expression profile of breast carcinomas with SRC differentiation. All breast carcinomas diagnosed at Centro Hospitalar S. Joao between 1996 and 2006 in which the pathology report mentioned the presence of SRCs (n=11) and four mucinous carcinomas were included in the study. The frequency of SRCs and immunohistochemistry expression of MUC1/MUC2/MUC5AC/MUC6 were evaluated. We confirmed that SRC differentiation can occur in different histological types, including ductal, lobular, mucinous and metaplastic carcinomas. The proportion of SRCs was highly variable (range: 8-70%). Tumors encompassed SRCs of intracytoplasmic lumina and goblet-cell type. A higher percentage of SRCs was associated with lymphovascular invasion (p=0.047). All tumors expressed cytoplasmic and membranous MUC1. Secretory mucins were more frequent in mucinous carcinomas and in carcinomas with extensive SRC differentiation. We conclude that besides the usefulness of mucin immunodetection for the differential diagnosis of carcinomas with SRC differentiation of breast origin, it is important to report SRC differentiation regardless of histological type because of its intrinsic prognostic value.
authors.affiliation: Department of Pathology, Portuguese Oncology Institute-Porto, Portugal; Department of Pathology, Centro Hospitalar São João, Porto, Portugal. Electronic address: carlabartosch@med.up.pt.
authors.forename: Carla
authors.initials: C
authors.lastname: Bartosch
authors.affiliation: IPATIMUP, Institute of Molecular Pathology and Immunology, Porto, Portugal.
authors.forename: Nuno
authors.initials: N
authors.lastname: Mendes
authors.affiliation: Department of Pathology, Centro Hospitalar São João, Porto, Portugal.
authors.forename: Elisabete
authors.initials: E
authors.lastname: Rios
authors.affiliation: Department of Pathology, Centro Hospitalar São João, Porto, Portugal.
authors.forename: Marta
authors.initials: M
authors.lastname: Rodrigues
authors.affiliation: IPATIMUP, Institute of Molecular Pathology and Immunology, Porto, Portugal.
authors.forename: Catarina
authors.initials: C
authors.lastname: Eloy
authors.affiliation: IPATIMUP, Institute of Molecular Pathology and Immunology, Porto, Portugal; Porto Medical Faculty, University of Porto, Portugal.
authors.forename: Celso A
authors.initials: CA
authors.lastname: Reis
authors.affiliation: Department of Pathology, Centro Hospitalar São João, Porto, Portugal; IPATIMUP, Institute of Molecular Pathology and Immunology, Porto, Portugal.
authors.forename: Isabel
authors.initials: I
authors.lastname: Amendoeira
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000378:metabolism*; D001943:Breast Neoplasms / Q000378:metabolism* / Q000473:pathology*; D018279:Carcinoma, Signet Ring Cell / Q000378:metabolism*; D002454:Cell Differentiation / Q000502:physiology; D048430:Cell Shape; D005260:Female; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods; D008562:Membrane Glycoproteins / Q000378:metabolism*; D008875:Middle Aged; D009077:Mucins / Q000378:metabolism*; D013274:Stomach Neoplasms / Q000378:metabolism / Q000473:pathology
chemical_list: D014408:Biomarkers, Tumor; D008562:Membrane Glycoproteins; D009077:Mucins
keywords: Breast carcinoma; MUC1; MUC2; MUC6; Mucins; Signet-ring cell