title: Cystic fibrosis transmembrane conductance regulator is helpful in the distinction of extra-mammary Paget's disease from squamous cell carcinoma in situ (Bowen's disease).
abstract: Cystic fibrosis transmembrane conductance regulator (CFTR) represents a cAMP-dependent channel found in normal apocrine glands. The classification and histogenesis of extra-mammary Paget's disease (EMPD) remains controversial, but it is generally accepted that primary EMPD exhibits apocrine differentiation. Therefore, we examined the utility of CFTR in the differential diagnosis of EMPD and squamous cell carcinoma in situ (SCCIS). Twenty-five cases of SCCIS and 14 cases of EMPD were evaluated for immunohistochemical expression of CFTR. Expression was scored as 0 (<5% of cells positive), 1+ (5-75% of cells positive) or 2+ (>75% cells positive). Twenty-three of 25 cases of SCCIS showed no reactivity for CFTR, and the remaining 2 cases showed 1+ staining. Thirteen of 14 cases of EMPD showed 2+ staining, while 1 case showed 1+ staining. We recognize that the pathological appearance along with clinical history and site of occurrence are sufficient to distinguish EMPD and SCCIS in most instances. However, distinction between the two can become more challenging when the location and histopathology are not characteristic. We conclude that when an immunohistochemical panel is diagnostically necessary, the expression of CFTR favors a diagnosis of EMPD over SCCIS.
authors.affiliation: Department of Pathology, Northshore University Health System, Evanston, IL 60201, USA.
authors.forename: Rick
authors.initials: R
authors.lastname: Bains
authors.forename: Briana C
authors.initials: BC
authors.lastname: Gleason
authors.forename: Antoinette B
authors.initials: AB
authors.lastname: Thomas
authors.forename: Thomas A
authors.initials: TA
authors.lastname: Victor
authors.forename: Thomas L
authors.initials: TL
authors.lastname: Cibull
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000032:analysis*; D001913:Bowen's Disease / Q000175:diagnosis*; D002278:Carcinoma in Situ / Q000175:diagnosis*; D019005:Cystic Fibrosis Transmembrane Conductance Regulator / Q000032:analysis* / Q000096:biosynthesis; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D010145:Paget Disease, Extramammary / Q000175:diagnosis*; D012878:Skin Neoplasms / Q000175:diagnosis*
chemical_list: D014408:Biomarkers, Tumor; C505032:CFTR protein, human; D019005:Cystic Fibrosis Transmembrane Conductance Regulator