Table 1.2.
Neoplastic lesions in lung cytopathology
| Conditions | Descriptions | Differentials |
|---|---|---|
| Adenocarcinoma | Three-dimensional and acinar/papillae arrangement of columnar cells with high N/C ratio, prominent nucleoli, and “lacy” cytoplasm with vacuolization (cytoplasmic mucin) | Large hyperchromatic nuclei with irregular nuclear membranes, coarse chromatin, prominent nucleoli |
| DD: poorly differentiated non-keratinizing squamous cell carcinoma | ||
| Squamous cell carcinoma | Discohesive and scattered individual polymorphic cells with hyperchromatic smudgy chromatin, dense cytoplasm with or without keratinization | Polygonal cells and elongated or tadpole-shaped cells with large hyperchromatic nuclei and dense cytoplasm |
| DD: poorly differentiated adenocarcinoma | ||
| Small cell carcinoma | Tight clusters of small hyperchromatic cells (two- to threefold of mature lymphocytes), fine (salt-and-pepper) chromatin, nuclear molding and crowding, nuclear stripes (broken down nuclear material), inconspicuous nuclei, scant cytoplasm | Fine chromatin texture and nuclear crowding and molding, mitosis, necrosis, and apoptotic body |
| DD: lymphoma, basaloid squamous cell carcinoma, and poorly differentiated adenocarcinoma | ||
| Undifferentiated large cell carcinoma | Loosely cohesive clusters, syncytial sheets, or scattered polymorphic large cells with coarse chromatin, single or multiple prominent nucleoli, and feathery cytoplasm | Large cells with large prominent nucleoli. Numerous mitoses |
| DD: poorly differentiated adenocarcinoma, sarcoma | ||
| Carcinoid | Loosely cohesive clusters and scattered individual cells arrange in rosette-like structures. Tumor cells are relatively uniform in size, with fine (“salt-pepper”) chromatin, and moderate cytoplasm | Monomorphic appearance of tumor cells, with fine chromatin, inconspicuous nucleoli. Branching capillaries in the background. No mitosis or necrosis |
| DD: small cell carcinoma, atypical carcinoid | ||
| Lymphoma | Discohesive and scattered individual cells with vesicular nuclei, clumped (soccer-ball-like) chromatin, irregular nuclear membrane, and scant cytoplasm. Lymphoglandular body in the background | Monomorphous population of cells, with clumped (soccer-ball-like) chromatin, irregular nuclear membranes, conspicuous nucleoli, and scant cytoplasm |
| DD: small cell carcinoma, carcinoid |