title: Myoepithelioma of the soft tissue of the head and neck: a case report and review of the literature.
abstract: BACKGROUND
  Extraglandular myoepitheliomas are neoplasms that seldom occur in the soft tissue of the head and neck region. Misdiagnosis of these neoplasms as more aggressive tumors can lead to unnecessary treatment.
  
  
  METHODS
  We describe a myoepithelioma of cervical soft tissue. The histopathology of the tumor, its immunophenotype, its differential diagnosis, and a review of the literature are presented.
  
  
  RESULTS
  Histopathologically, the tumor was composed of epithelioid cells with eosinophilic cytoplasm and eccentric nuclei arranged in cords and files. On immunohistochemical analysis, the cells expressed cytokeratin 14, calponin, glial fibrillary acid protein, and p63 and showed focal positivity for S-100 protein. Together, these markers identified the cells as myoepithelial type. A literature review identified only five cases of myoepithelioma in the soft tissue of the head and neck region in which detailed clinical information was provided.
  
  
  CONCLUSIONS
  Myoepitheliomas can have cells with variable morphology arranged in different histologic patterns. Immunohistochemical analysis is crucial for unequivocal diagnosis when myoepitheliomas occur in extraglandular locations.
authors.affiliation: Department of Pathology and Laboratory Medicine, The University of Texas M. D. Anderson Cancer Center, 1515 Holcombe Boulevard, Houston, Texas 77030, USA.
authors.forename: Antonio Galvao
authors.initials: AG
authors.lastname: Neto
authors.forename: Keyla
authors.initials: K
authors.lastname: Pineda-Daboin
authors.forename: Mario A
authors.initials: MA
authors.lastname: Luna
mesh_terms: D001707:Biopsy, Needle; D005500:Follow-Up Studies; D006258:Head and Neck Neoplasms / Q000473:pathology* / Q000601:surgery; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D009208:Myoepithelioma / Q000473:pathology* / Q000601:surgery; D018570:Risk Assessment; D012983:Soft Tissue Neoplasms / Q000473:pathology* / Q000601:surgery; D016896:Treatment Outcome