Cytopathologic diagnosis of xanthogranulomatous cholecystitis and coexistent lesions. A prospective study of 31 cases

OBJECTIVE: To evaluate the diagnostic accuracy and reliability of preoperative ultrasound (US)-guided fine needle aspiration cytology (FNAC) in the diagnosis of xanthogranulomatous cholecystitis (XGC) and coexistent lesions (carcinoma) and also to evaluate the possibility ofmissing either carcinoma or XGC on cytology. STUDY DESIGN: The cytologic diagnoses of XGC and coexistent lesions were made according to standard criteria. In a prospective, 5-year study, preoperative US-guided FNAC from 42 cases of XGC was compared with follow-up histologic diagnoses, which were available in 31 cases. When FNAC after the first aspiration showed the aspirate to be nondiagnostic, FNAC was repeated under US guidance. RESULTS: Preoperative US-guided FNAC diagnoses of XGC were made in 31 cases, for which follow-up histology was available in all cases. US-guided FNAC diagnosis ofXGC only was made in 30 cases and coexistent lesions in 1 case. Followup histology revealed 26 cases of XGC, 4 of a coexistent lesion and 1 of squamous cell carcinoma only. The overall diagnostic accuracy of preoperative US-guided FNAC was 96.77%. The overall possibility of missing XGC was 3.33% and that of carcinoma, 12.01%. CONCLUSION: Preoperative US-guided FNAC is safe, rapid, reliable, cost-effective and accurate in diagnosing XGC. However, the possibility ofcoexistent carcinoma cannot be definitely ruled out. It is therefore recommended that FNAC be performed from multiple suspicious sites under radiologic guidance. Thus, preoperative US-guided FNAC diagnosis would help in determining the urgency of treatment and also in planning the surgical procedure for gallbladder lesions.