title: Epithelial-Myoepithelial Carcinoma of the Salivary Gland Harboring HRAS Codon 61 Mutations With Lung Metastasis.
abstract: Here, we report a case involving a 43-year-old man diagnosed with Burkitt lymphoma in 2007. At the same time, 2 small lung nodules were incidentally found; however, they presented no indication of growth throughout the follow-up period. However, a 1.5-cm nodule located in the right parotid gland in 2010 gradually increased in size to 2.8 cm by 2012. A parotidectomy revealed an epithelial-myoepithelial carcinoma, characterized by biphasic tubular structures and solid areas presenting myoepithelial overgrowth. Tumor necrosis and regional lymph node invasion were also observed. During clinical follow-up in 2013, a new 1.3-cm nodule was identified in the left lower lobe of the lung, which enlarged to 3 cm by 2014. Wedge resection of the left lung nodules revealed round nodes with well-defined borders. Histologically, these lung tumors predominantly comprised spindle-shaped myoepithelial cells with occasional tubular structures. Numerous cleft-like spaces lined by entrapped TTF-1-immunoreactive pneumocytes were observed inside the nodules. The lung nodules were characterized by a morphology similar to that of the parotid cancer. Epithelial-myoepithelial carcinoma with lung metastasis was confirmed by molecular testing, which revealed identical HRAS codon 61 (Q61K) mutations in the primary parotid tumor as well as in the lung metastases.
authors.affiliation: National Taiwan University Hospital, Taipei, Taiwan National Taiwan University College of Medicine, Taipei, Taiwan.
authors.forename: Min-Shu
authors.initials: MS
authors.lastname: Hsieh
authors.affiliation: National Taiwan University Hospital, Taipei, Taiwan National Taiwan University College of Medicine, Taipei, Taiwan.
authors.forename: Jin-Shing
authors.initials: JS
authors.lastname: Chen
authors.affiliation: National Taiwan University Hospital, Taipei, Taiwan National Taiwan University College of Medicine, Taipei, Taiwan.
authors.forename: Yi-Hsuan
authors.initials: YH
authors.lastname: Lee
authors.affiliation: Far Eastern Memorial Hospital, New Taipei City, Taiwan komet1414@gmail.com.
authors.forename: Yueh-Hung
authors.initials: YH
authors.lastname: Chou
mesh_terms: D000328:Adult; D002051:Burkitt Lymphoma / Q000473:pathology; D002277:Carcinoma / Q000235:genetics / Q000473:pathology*; D003062:Codon; D006801:Humans; D008175:Lung Neoplasms / Q000556:secondary; D008297:Male; D009154:Mutation; D009208:Myoepithelioma / Q000235:genetics / Q000473:pathology*; D016609:Neoplasms, Second Primary / Q000473:pathology*; D010307:Parotid Neoplasms / Q000235:genetics / Q000473:pathology*; D016283:Proto-Oncogene Proteins p21(ras) / Q000235:genetics*; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D003062:Codon; C501009:HRAS protein, human; D016283:Proto-Oncogene Proteins p21(ras)
keywords: HRAS; epithelial-myoepithelial carcinoma; lung metastasis; salivary gland