title: The role of fine-needle aspiration cytology in the evaluation of metastatic clear cell tumors.
abstract: BACKGROUND
  Clear cell tumors (CCTs) occur as primary neoplasms in a number of anatomic sites. Due to their overlapping morphologic features, these tumors can be challenging for the cytologist, particularly when they present as metastatic lesions.
  
  
  METHODS
  Forty-nine fine-needle aspirations (FNA) of metastatic CCTs from 46 patients (age range, 29-87 years; mean, 64 years) were reviewed retrospectively. In addition to the routine smears and cell block preparations, ancillary studies were performed in selected cases. Clinical and/or histologic follow-up was obtained for all patients.
  
  
  RESULTS
  The sites of the 49 FNAs were the lung (12 cases), lymph nodes (9 cases), liver (7 cases), bone (7 cases), soft tissue (4 cases), pelvis (2 cases), adrenal gland (2 cases), pancreas (1 case), thyroid (2 cases), peritoneum (2 cases), and vagina (1 case). Twenty-seven patients had a previous history of a CCT and the FNA material in these cases was consistent with a metastasis. The primary anatomic sites in these cases were the kidney (20 cases), ovary (2 cases), salivary gland (1 case), and cervix (1 case). On light microscopy, these tumors had a similar appearance and often were indistinguishable. Nineteen patients did not have a prior history of malignancy; 12 of these patients had a concurrent renal mass and the diagnosis of metastatic renal cell carcinoma was made. The anatomic site of origin of seven of the ten remaining tumors (kidney [2 cases], lung [2 cases], ovary [1 case], germ cell [1 case], and endometrium [1 case]) was established through immunocytochemical studies of cytologic material and clinical follow-up.
  
  
  CONCLUSIONS
  FNA plays an important role in the diagnosis of metastatic CCT. Cytologic examination, ancillary studies, and clinical information can establish the anatomic site of origin in the majority (95%) of cases, precluding the necessity of obtaining additional tissue. Cancer (Cancer Cytopathol)
authors.affiliation: Department of Pathology, The University of Iowa Hospitals and Clinics, Iowa City, Iowa 52242-1009, USA.
authors.forename: J H
authors.initials: JH
authors.lastname: Hughes
authors.forename: C S
authors.initials: CS
authors.lastname: Jensen
authors.forename: A D
authors.initials: AD
authors.lastname: Donnelly
authors.forename: M B
authors.initials: MB
authors.lastname: Cohen
authors.forename: J F
authors.initials: JF
authors.lastname: Silverman
authors.forename: K R
authors.initials: KR
authors.lastname: Geisinger
authors.forename: S S
authors.initials: SS
authors.lastname: Raab
mesh_terms: D018262:Adenocarcinoma, Clear Cell / Q000473:pathology / Q000556:secondary*; D000310:Adrenal Gland Neoplasms / Q000473:pathology / Q000556:secondary; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001707:Biopsy, Needle; D001859:Bone Neoplasms / Q000473:pathology / Q000556:secondary; D002292:Carcinoma, Renal Cell / Q000473:pathology / Q000556:secondary*; D003581:Cytodiagnosis; D005260:Female; D005500:Follow-Up Studies; D018237:Germinoma / Q000473:pathology / Q000556:secondary; D006801:Humans; D008113:Liver Neoplasms / Q000473:pathology / Q000556:secondary; D008175:Lung Neoplasms / Q000473:pathology / Q000556:secondary; D008207:Lymphatic Metastasis / Q000473:pathology; D008297:Male; D008875:Middle Aged; D010190:Pancreatic Neoplasms / Q000473:pathology / Q000556:secondary; D010386:Pelvic Neoplasms / Q000473:pathology / Q000556:secondary; D010534:Peritoneal Neoplasms / Q000473:pathology / Q000556:secondary; D012189:Retrospective Studies; D012983:Soft Tissue Neoplasms / Q000473:pathology / Q000556:secondary; D013964:Thyroid Neoplasms / Q000473:pathology / Q000556:secondary; D014625:Vaginal Neoplasms / Q000473:pathology / Q000556:secondary