title: Histopathologic, immunophenotypic and cytogenetic features of pulmonary mucoepidermoid carcinoma.
abstract: Pulmonary mucoepidermoid carcinoma is an uncommon but distinctive manifestation of mucoepidermoid carcinoma. Pulmonary mucoepidermoid carcinoma occurs in adults and children and can cause diagnostic problems, especially in small biopsies. Few studies have characterized the histologic and immunophenotypic features of pulmonary mucoepidermoid carcinoma. t(11;19)(q21;p13) is considered disease-defining for mucoepidermoid carcinoma; its significance in pulmonary mucoepidermoid carcinoma warrants further study. Forty three pulmonary mucoepidermoid carcinomas were re-reviewed and graded according to the Brandwein grading system for mucoepidermoid carcinoma. Four cases were excluded because of a split opinion between pathology report and re-review. These cases were negative for MAML2 rearrangement by FISH. TTF-1, napsin A, p40 and p63 immunostains were scored: 0 (negative), 1 (1-25% tumor cells), 2 (26-50%), 3 (51-75%) or 4 (>75%). FISH to detect MAML2 rearrangement used a MAML2-11q21 break-apart probe. Thirty nine pulmonary mucoepidermoid carcinoma (4 low, 30 intermediate, 5 high grade) contained mucous, epidermoid and intermediate cells and lacked keratinization and in situ carcinoma of the overlying epithelium. All cases with available gross description (n=22) had a central/endo- or peribronchial location. All 25 cases tested for immunohistochemistry were positive (scores 1-4) for p63; 23 also expressed p40. In six cases, the p63 score was higher than p40. TTF-1 and napsin were uniformly negative in all 25 cases. MAML2 rearrangement was identified by FISH in each of the 24 cases tested (3 low, 19 intermediate, 2 high grade). Clinical history was available in 29 patients (15 men) (median age, 48 years) with follow-up in 24 (median, 8.4 years). Five patients died of unrelated causes; one developed metastatic pulmonary mucoepidermoid carcinoma. In conclusion, features helpful in distinguishing pulmonary mucoepidermoid carcinoma from other lung cancers include its central/endo- or peribronchial location together with the presence of mucous cells, p63 expression, lack of keratinization and MAML2 rearrangement. TTF-1 and napsin are typically not expressed.
authors.affiliation: Department of Laboratory Medicine & Pathology, Mayo Clinic, Rochester, MN, USA.
authors.forename: Anja C
authors.initials: AC
authors.lastname: Roden
authors.affiliation: Department of Laboratory Medicine & Pathology, Mayo Clinic, Rochester, MN, USA.
authors.forename: Joaquín J
authors.initials: JJ
authors.lastname: García
authors.affiliation: Department of Laboratory Medicine & Pathology, Mayo Clinic, Rochester, MN, USA.
authors.forename: Rebecca N
authors.initials: RN
authors.lastname: Wehrs
authors.affiliation: Department of Laboratory Medicine & Pathology, Mayo Clinic, Arizona, AZ, USA.
authors.forename: Thomas V
authors.initials: TV
authors.lastname: Colby
authors.affiliation: Department of Laboratory Medicine & Pathology, Mayo Clinic, Jacksonville, FL, USA.
authors.forename: Andras
authors.initials: A
authors.lastname: Khoor
authors.affiliation: Department of Laboratory Medicine & Pathology, Mayo Clinic, Arizona, AZ, USA.
authors.forename: Kevin O
authors.initials: KO
authors.lastname: Leslie
authors.affiliation: Department of Laboratory Medicine & Pathology, Mayo Clinic, Arizona, AZ, USA.
authors.forename: Longwen
authors.initials: L
authors.lastname: Chen
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D016282:Aspartic Acid Endopeptidases / Q000032:analysis; D014408:Biomarkers, Tumor / Q000032:analysis / Q000235:genetics; D018277:Carcinoma, Mucoepidermoid / Q000737:chemistry / Q000175:diagnosis* / Q000235:genetics / Q000473:pathology; D002648:Child; D004268:DNA-Binding Proteins / Q000235:genetics; D005260:Female; D015321:Gene Rearrangement; D006801:Humans; D007150:Immunohistochemistry; D017404:In Situ Hybridization, Fluorescence; D008175:Lung Neoplasms / Q000737:chemistry / Q000175:diagnosis* / Q000235:genetics / Q000473:pathology; D008297:Male; D008875:Middle Aged; D060787:Neoplasm Grading; D009687:Nuclear Proteins / Q000235:genetics; D011237:Predictive Value of Tests; D013997:Time Factors; D015534:Trans-Activators; D014157:Transcription Factors / Q000032:analysis / Q000235:genetics; D025521:Tumor Suppressor Proteins / Q000032:analysis; D055815:Young Adult
chemical_list: D014408:Biomarkers, Tumor; D004268:DNA-Binding Proteins; C471297:MAML2 protein, human; D009687:Nuclear Proteins; C115051:TP63 protein, human; D015534:Trans-Activators; D014157:Transcription Factors; D025521:Tumor Suppressor Proteins; D016282:Aspartic Acid Endopeptidases; C498549:NAPSA protein, human