Role of FNAC, fluid specimens, and cell blocks for cytological diagnosis of lung cancer in the present era

Abstract

Cytoblocks prepared from residual tissue fluids and fine-needle aspirations can be useful adjuncts to smears for establishing a more definitive cytopathologic diagnosis. These paraffin embedded cytoblocks have been popular since these can be handled like any other histologic specimen. Rapid on-site evaluation (ROSE) can help in attaining adequate material in the cytoblock, which is a major concern to the cytopathologists. Ancillary studies can be done using cytoblocks including IHC and various molecular techniques. The opportunities for cytopathologists to influence therapy, and uncover strategies in the complex field of lung cancer are exciting and limitless especially in the presence of an adequate cytoblock.

Keywords: Cytology; epidermal growth factor receptor (EGFR) mutations; fine-needle aspiration cytology (FNAC); immunochemistry; lung cancer.

Figure 1

A panel of microphotographs of pulmonary squamous-cell carcinoma (a) Tumor cell cluster with necrosis in the background (MGG, ×400); (b) Cell block showing squamoid differentiation of tumor cells (H and E, ×400); (c) Nuclear positivity for p63 (IHC, ×1000) (d) Cytoplasmic positivity for CK5/6 (IHC, ×1000)

Figure 2

A group of microphotographs of pulmonary adenocarcinoma (a) Tumor cell cluster (MGG, ×400) (b) Cell block showing a cluster of tumor cells (H and E, ×400) (c) Nuclear positivity for TTF-1 (IHC, ×400) (d) Cytoplasmic positivity for CK7 (IHC, ×400)