Fine-needle aspiration cytology of gallbladder with an attempt of cytomorphological classification

Background: Image-guided fine-needle aspiration has emerged as an effective diagnostic tool for precise diagnosis of deep-seated lesions. Although occasional studies have made an attempt to classify the gallbladder carcinoma on cytology, literature lacks the standardized cytological nomenclature system used for it. The present study was conducted to study the role of fine-needle aspiration cytology (FNAC) in diagnosis of gallbladder lesions with an attempt of cytomorphological classification. Methods: The study included cases of image-guided FNAC of the gallbladder over a period of 3½ years. An attempt was made to categorize gallbladder lesions on basis of architectural and cytomorphological features along with analysis of management. Results: The study included 433 cases and lesions were categorized on FNAC into five categories ranging from Category 1 (inadequate), Category 2 (negative for malignancy), Category 3 (atypical cells), Category 4 (highly atypical cells suggestive of malignancy), and Category 5 (positive for malignancy). The most common architectural pattern observed on FNAC of neoplasm was sheets and acini with predominance of columnar cells and adenocarcinoma being the most common malignancy. The histopathological diagnosis was available in 93 cases with cytohistopathological concordance of 94.4% in malignant cases. Conclusions: Image-guided FNAC plays an important role in diagnosis of gallbladder lesions with minimal complications. The cytomorphological classification of gallbladder lesions provides an effective base for accurate diagnosis and management. Category 3 and 4 are the most ambiguous category on FNAC which should be managed by either repeat FNAC or surgery in the light of worrisome radiological features. The vigilant examination of architectural pattern and cytomorphological features of the smears may be helpful in clinching the diagnosis and precisely subtyping malignant tumors along with prognostication of these tumors.