title: Primary cutaneous versus salivary gland origin mucoepidermoid carcinoma.
abstract: Mucoepidermoid carcinoma (MEC) is a malignant glandular epithelial neoplasm that most commonly arises in the major salivary glands. Primary cutaneous MEC is very rare. There is a particular diagnostic challenge in determining the primary site of MEC when it is found in skin overlying the parotid gland. Attention to a combination of morphologic findings may be helpful. However, differentiation of primary cutaneous MEC from secondary cutaneous involvement by a parotid MEC may be unnecessary once the parotid gland is infiltrated. We report the case of a 54-year-old male with a 2-cm asymptomatic mass overlying the right parotid gland, which was managed by excision of the affected skin, right total parotidectomy, and right neck dissection. Histopathologic and immunohistochemical findings were consistent with a cutaneous intermediate-grade MEC. Postoperative radiotherapy was deferred. The patient showed no evidence of recurrence or metastasis at 2 months before self-discontinuing follow-up. To our knowledge, this is only the second reported case of MEC involving the parotid gland, but of overlying primary cutaneous origin.
authors.affiliation: *Department of Pathology and Molecular Medicine, McMaster University, Hamilton Health Sciences, Hamilton, Ontario, Canada; and †Department of Pathology and Molecular Medicine, McMaster University, St Joseph's Healthcare Hamilton, Hamilton, Ontario, Canada.
authors.forename: Ryan
authors.initials: R
authors.lastname: Yu
authors.forename: Samih
authors.initials: S
authors.lastname: Salama
authors.forename: Salem
authors.initials: S
authors.lastname: Alowami
mesh_terms: D014408:Biomarkers, Tumor / Q000032:analysis; D018277:Carcinoma, Mucoepidermoid / Q000556:secondary*; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D010307:Parotid Neoplasms / Q000473:pathology*; D012878:Skin Neoplasms / Q000556:secondary*
chemical_list: D014408:Biomarkers, Tumor