A 59-year-old woman presents with right upper quadrant pain, weight loss, and jaundice. Vital signs show BP 128/82, HR 92, RR 16, Temp 37.2°C, SpO2 98%. CT abdomen reveals a 4-cm heterogeneous liver mass with elevated transaminases (AST 187 U/L). Liver biopsy demonstrates nests of atypical epithelial cells without lymphoid aggregates. Which immunohistochemical stain would best differentiate carcinoma from sarcoma or lymphoma in this metastatic malignancy of unknown primary?

  1. A)Glial fibrillary acidic protein
  2. B)CytokeratinGABARITO
  3. C)Desmin
  4. D)CD31
  5. E)Vimentin

Explicação

Cytokeratins are intermediate filaments expressed in epithelial cells and are commonly used to identify carcinomas. Positive cytokeratin staining supports epithelial origin in a metastatic tumor. Ver explicação completa e trilha adaptativa →

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