Preoperative diagnosis of squamous cell carcinoma of the gallbladder by ultrasound-guided aspiration cytology: clinical and cytological findings of nine cases.

INTRODUCTION: Squamous cell carcinoma is a rare tumour of the gallbladder and accounts for about 1% of all the malignant neoplasms of the gallbladder. The clinical presentation of patients with squamous cell carcinoma of the gallbladder is not specific, and in majority, it mimics that of acute cholecystitis. As a result, preoperative diagnosis is not made, and patients undergo operative procedures. Squamous cell carcinoma of the gallbladder is detected at an advanced stage with infiltration into adjacent structures, with infiltration of the liver being the commonest. Ultrasound-guided fine-needle aspiration cytology is considered an important minimally invasive investigation in the preoperative diagnosis of adenocarcinoma of the gallbladder. However, sparse literature is available regarding preoperative fine-needle aspiration diagnosis of squamous cell carcinoma of the gallbladder.
METHODS: On retrospective analysis of ultrasound-guided fine-needle aspiration cytology of gallbladder lesions, nine cases of pure squamous cell carcinoma were identified. Clinical and cytopathological features were analysed for these cases and compared with those of adenocarcinoma of the gallbladder.
RESULTS: Patients presented with non-specific abdominal symptoms, and on radiological assessment, eight out of nine cases had evidence of local infiltration. Four of these cases had pathologically documented evidence of liver infiltration. Cytology showed presence of atypical squamous cells with keratinized cytoplasm, tadpole cells and giant cells along with necrosis. Eight of the nine cases were inoperable, and only a single patient underwent hepatopancreaticoduodenectomy along with cholecystectomy. Three patients received cisplatin and gemcitabine-based chemotherapy.
CONCLUSION: Ultrasound-guided fine-needle aspiration is a useful minimally invasive investigation in the preoperative diagnosis of squamous cell carcinoma of the gallbladder and can be helpful in deciding the management and prognostication of the patient.