title: Basement membrane material (hyaline globules) in synovial sarcoma. A case report with description of a potential diagnostic pitfall.
abstract: BACKGROUND
  Synovial sarcoma (SS), a malignant mesenchymal tumor, has a biphasic growth pattern characteristically. Histologically and cytologically the tumor can pose diagnostic difficulty when the epithelial component is predominant.
  
  
  METHODS
  A 22-year-old female presented with a rapidly enlarging mass on the lower left side of the neck. Fine needle aspiration of the tumor yielded abundant, discohesive round-oval cells mingled with amorphous hyaline material, raising a suspicion of medullary carcinoma of the thyroid. In addition, air-dried, Giemsa-stained smears demonstrated rosettelike structures with central magenta globular material, mimicking adenoid cystic carcinoma. However, histologic examination of the excised tumor, including immunohistochemical and ultrastructural studies, proved it to be a typical SS with copious basement membrane accumulations.
  
  
  CONCLUSIONS
  The cytologic appearance of SS can be confusing. However, a false diagnosis may be avoided if adequate needle sampling is ensured and clinical correlation considered.
authors.affiliation: Department of Ear, Nose and Throat Surgery, Haemek Medical Center, Afula, Israel.
authors.forename: M
authors.initials: M
authors.lastname: Dharan
authors.forename: D
authors.initials: D
authors.lastname: Nachtigal
authors.forename: G
authors.initials: G
authors.lastname: Rosen
authors.forename: J
authors.initials: J
authors.lastname: Honigman
authors.forename: R
authors.initials: R
authors.lastname: Luboshitzky
mesh_terms: D000328:Adult; D001485:Basement Membrane / Q000737:chemistry / Q000473:pathology*; D014408:Biomarkers, Tumor / Q000032:analysis; D001707:Biopsy, Needle; D018276:Carcinoma, Medullary / Q000175:diagnosis; D003094:Collagen / Q000032:analysis; D003937:Diagnosis, Differential; D005260:Female; D006258:Head and Neck Neoplasms / Q000737:chemistry / Q000175:diagnosis / Q000473:pathology* / Q000532:radiotherapy; D006801:Humans; D007797:Laminin / Q000032:analysis; D009363:Neoplasm Proteins / Q000032:analysis; D009364:Neoplasm Recurrence, Local; D013584:Sarcoma, Synovial / Q000737:chemistry / Q000175:diagnosis / Q000473:pathology* / Q000532:radiotherapy; D013964:Thyroid Neoplasms / Q000175:diagnosis
chemical_list: D014408:Biomarkers, Tumor; D007797:Laminin; D009363:Neoplasm Proteins; D003094:Collagen