Tumor Cell Representation by an Improvised Technique of Fine-Needle Aspiration Specimen Acquisition and Cell Block Preparation: Our Experience in Lung Cancer Cases in a Peripheral Center of Eastern India

Abstract

Background: Being a minimally invasive diagnostic technique, Fine-Needle Aspiration Cytology (FNAC) has become the first-line test and corresponding aspirated material has become the target specimen for diagnosis and ancillary tests in lung carcinoma. Although the role of Cell Blocks (CBs) in diagnosis and in ancillary testing is well recognized in literature, limited attention has been paid to specimen procurement and triage in the preparation of CBs. In the present scenario, CBs are not consistently optimal because of its low cellularity.

Aims: This study is aimed to describe an improvised technique of specimen acquisition and cell block preparation in CT-guided FNACs of lung carcinoma cases in a resource-constrained center and to assess its efficacy for optimal representation of cellularity, morphology, and architecture.

Materials and methods: Total 85 lung carcinoma cases undergoing CT-guided FNAC in our center from February 2017 to January 2018 were included in this study. 4 to 5 direct smears and subsequent CBs were made from material obtained by single pass. Cellularity of smears and corresponding cell blocks were assessed and categorized according to a scoring system (score 1 to 3 for number of cells <50, 50-100, >100, respectively). Preserved architecture and morphology were also assessed in smears and CBs.

Results: The evaluated samples showed a cellularity score 3 in 65.4%CBs and score 2 in 24.7% CBs. Overall, 90.1% cell blocks had acceptable cellularity. Cell morphology was preserved in all CBs of acceptable cellularity, except for two adenocarcinoma, one squamous cell carcinoma, and one small cell carcinoma blocks. Cellular architecture was also preserved in all CBs of acceptable cellularity.

Conclusions: This simple improvised technique of CB preparation optimized its cellularity, morphology, and architectural preservation, even after adequate cellular FNA smears.

Keywords: Architecture; cell block; cellularity; fine-needle aspiration cytology; lung cancer; morphology.

Figure 1

Composite image showing cellularity, intact cell morphology, and different architectural patterns of lung adenocarcinoma in cell block preparation. (a) Acinar pattern, (b) papillary pattern, (c) clusters with intracellular mucin, and (d) cribriform pattern. [Figure 1a-1c: H and E stain, 400 × magnification; Figure 1d: H and E stain, 100 × magnification]

Figure 2

(a and b): Composite image showing cellularity and intact cell morphology of squamous cell carcinoma in cell block preparation. (a) Sheets of cells with keratin pearl formation. (b) Cluster of malignant cells with intercellular bridges. (c) Microphotograph showing small cell carcinoma. (d) Microphotograph showing nonsmall cell carcinoma with high cellularity and intact cell morphology. [Figure 2a-2c: H and E stain, 400 × magnification; Figure 2d: H and E stain, 100 × magnification]