Comparative study of cell block versus centrifuged smear examination from aspirates of cystic lesions

Abstract

Background: Cystic fluids encountered during routine FNA poses a diagnostic challenge to cytopathologists due to its low cell yield with high dispersal of cells on conventional centrifuged smears (CS). Cell Block (CB) technique enables retrieval of small tissue fragments from fluids, thereby providing scope for better morphology and material for ancillary techniques which help in improving the diagnosis. Aim:To compare the efficacy of CB versus CS, in cyto-diagnosis of cystic lesions. Methods:This observational study was conducted on a total of 50 fluid samples aspirated from cystic lesions during routine FNA and fluids aspirated peri-operatively from cystic ovarian lesions. Divided into two equal parts, one part was processed for CS and CB by Fixed Sediment Method and relevant immunohistochemistry was performed. CSs were categorized as positive for malignancy, benign diagnosis, Inadequate for opinion and suspicious for malignancy. CBs were categorized as; no material, Non-contributory (CS+, CB-), confirms the smear diagnosis and establishes a specific diagnosis. The comparison between CS and CB was analysed by Chi-square test & kappa test. Results:Out of the 50 cases, 35(70%) were given a benign diagnosis, 10 (20%) were positive for malignancy, 2(4%) were suspicious and 3(6%) were inadequate for opinion on CS. In CB out of 50 cases, 29 of them confirmed/established a diagnosis and 21 cases were non diagnostic / non-contributory. CB gave an improved diagnosis in 2 out of 10 (20% ) malignant cases and 2 out of 35 (5.7%) benign cases. ( p value = 0.00054, Kappa value =0.34) Conclusions: CBs complemented CS, more so in malignant lesions by preserved architecture. Aspirates from multiple sites of the cystic lesions (with/without radiological assistance) pooled as one specimen yielded better material for CBs and ancillary techniques like histochemistry and IHC.

How Essential Is Cell Block Preparation in Each and Every Specimen of Body Fluid Sent for Cytology in Addition to Conventional Smear- An Observational and Analytical Study in a Tertiary Care Centre

“…They showed that CB gave an improved diagnosis in 20% cases of malignancy and concluded CB complemented CS, especially in malignant cases. 13 Nair GG et al concluded that both CB and CS had high specificity, but sensitivity of CB is greater than CS to detect malignancy.…”