title: Aspiration cytology of malignant neoplasms associated with granulomas and granuloma-like features: diagnostic dilemmas.
abstract: BACKGROUND
  Malignant lymphomas and solid tumors that mimic or are associated with epithelioid granulomas are widely recognized in surgical pathology, but have received little attention in the cytopathology literature. In this study the authors present their experience with six such cases in which the presence of granulomas or granuloma-like features posed a diagnostic difficulty on fine-needle aspiration cytology (FNAC).
  
  
  METHODS
  Clinical data, FNAC, and follow-up surgical specimens from six patients presenting with neck masses were reviewed.
  
  
  RESULTS
  Only one case was diagnosed confidently as metastatic squamous cell carcinoma with an extensive granulomatous response; the other five were interpreted as "atypical" with descriptive cytology and a differential diagnoses including granulomatous inflammation, in addition to a caveat of "cannot exclude malignancy." Biopsy studies in these cases were recommended in view of the atypical cytologic findings and strong clinical suspicion of malignancy in each case. The histologic findings in two cases revealed Hodgkin's disease with exuberant granulomatous response. The remaining three cases were found to be malignant neoplasms with epithelioid morphologic features and included one example each of diffuse large cell lymphoma, anaplastic carcinoma of the thyroid, and lymphoepithelial carcinoma.
  
  
  CONCLUSIONS
  Malignancies associated with granulomas and tumor cells mimicking epithelioid histiocytes may be difficult to diagnose accurately on FNAC. The cytologic differential diagnosis of a "granulomatous" process should include malignant neoplasms. Excisional biopsy studies may be required for definitive diagnosis.
authors.affiliation: Department of Pathology, The State University of New York, Syracuse 13210, USA.
authors.forename: K K
authors.initials: KK
authors.lastname: Khurana
authors.forename: M W
authors.initials: MW
authors.lastname: Stanley
authors.forename: C N
authors.initials: CN
authors.lastname: Powers
authors.forename: M B
authors.initials: MB
authors.lastname: Pitman
mesh_terms: D000328:Adult; D000368:Aged; D001707:Biopsy, Needle / Q000379:methods / Q000592:standards; D002277:Carcinoma / Q000473:pathology; D002294:Carcinoma, Squamous Cell / Q000473:pathology; D003937:Diagnosis, Differential; D005260:Female; D006099:Granuloma / Q000473:pathology*; D006258:Head and Neck Neoplasms / Q000473:pathology*; D006689:Hodgkin Disease / Q000473:pathology; D006801:Humans; D016403:Lymphoma, Large B-Cell, Diffuse / Q000473:pathology; D008297:Male; D008875:Middle Aged; D013964:Thyroid Neoplasms / Q000473:pathology