title: Germ cell tumour as a diagnostic pitfall of metastatic carcinoma.
abstract: OBJECTIVE
  Testicular germ cell tumours may present as metastases in cervical lymph nodes, yet the primary tumours remain clinically occult. The aim of the study is to alert pathologists and clinicians to this uncommon but important presentation and highlight the clues and the diagnostic adjuncts to its correct diagnosis.
  
  
  METHODS
  The clinical, cytological, histological, and immunohistochemical features of two patients with germ cell tumour initially presenting as cervical lymphadenopathy were described and analysed.
  
  
  RESULTS
  Both patients were young adult males, who were found to have metastatic undifferentiated carcinoma on fine needle aspiration of the enlarged cervical lymph nodes. The tumour cells in both cases were positive for placental alkaline phosphatase (PLAP) and negative for epithelial membrane antigen (EMA).
  
  
  CONCLUSIONS
  Clinicians and pathologists should be aware of the possibility of germ cell tumour when encountering a young adult male with metastatic poorly differentiated carcinoma. Positivity for PLAP and negativity for EMA are helpful adjuncts in arriving at the correct diagnosis.
authors.affiliation: Department of Pathology, University of Hong Kong, Queen Mary Hospital.
authors.forename: T W
authors.initials: TW
authors.lastname: Shek
authors.forename: S T
authors.initials: ST
authors.lastname: Yuen
authors.forename: I S
authors.initials: IS
authors.lastname: Luk
authors.forename: M P
authors.initials: MP
authors.lastname: Wong
mesh_terms: D000328:Adult; D000469:Alkaline Phosphatase / Q000032:analysis; D014408:Biomarkers, Tumor / Q000032:analysis; D001707:Biopsy, Needle; D003937:Diagnosis, Differential; D018237:Germinoma / Q000737:chemistry / Q000473:pathology / Q000556:secondary*; D006801:Humans; D007150:Immunohistochemistry; D007527:Isoenzymes / Q000032:analysis; D008207:Lymphatic Metastasis / Q000473:pathology*; D008297:Male; D018396:Mucin-1 / Q000032:analysis; D009333:Neck; D013736:Testicular Neoplasms / Q000737:chemistry / Q000201:enzymology / Q000473:pathology*
chemical_list: D014408:Biomarkers, Tumor; D007527:Isoenzymes; D018396:Mucin-1; C055791:germ-cell AP isoenzyme; D000469:Alkaline Phosphatase