Accuracy of fine needle aspiration biopsy processed by cytologic smear and cell block techniques for the diagnosis of lacrimal gland tumors: a study of 48 cases

Objective: To study the accuracy of fine needle aspiration biopsy (FNAB) processed by smear cytology and cell block (CB) techniques for the diagnosis of lacrimal gland tumors (LGTs). Study Design: In a prospective study, we enrolled 48 consecutive patients with LGTs. Immediately after excision of LGTs, the tissues were underwent FNAB with 23-gauge needles. The FNAB samples were processed to produce cytologic smears and CB from which slides were cut for immunohistochemical staining. The remainders were submitted for routine histopathologic processing. The diagnostic value of FNAB was assessed by comparing the FNAB diagnoses to those made by routine histopathology. Results: Cytopathologic evaluations based on smear cytology and CB with sections stained immunohistochemically can distinguish non-epithelial lesions from epithelial ones in all cases. The diagnostic sensitivities, specificities, and accuracies for distinguishing benign from malignant lesions were: cytologic smears--76%, 68%, and 71%, respectively; CB with immunohistochemical staining--88%, 87%, and 88%, respectively. The accuracy of the tissue diagnosis compared to routine histopathology was less for cytologic smears (58%) than for CB with immunohistochemistry (81%; P < 0.05). Conclusions: FNAB of LGT processed using a CB technique capable of producing immunohistochemically stained slides results in a greater percentage of accurate tissue diagnoses than do cytologic smears, when compared to routine histopathology.