Pathology of small cell carcinoma of the lung

Cytologic preparation of SCLC. Notice the high nuclear-to-cytoplasmic ratio, the hyperchromatic blue color of the nuclei, and overall poor preservation with crush artifact.

Low-power view of small cell carcinoma on cytology. Note the monomorphic appearance of a “small round blue” cell tumor and the “salt and pepper” chromatin pattern.

Fine needle aspirate of small cell carcinoma showing areas of squamous differentiation in the form of very large eosinophilic cells with generous amounts of cytoplasm.

Tissue section of carcinoid tumor demonstrating bland nuclear morphology, but note the neuroendocrine similarity to small cell carcinoma and the trabecular arrangement.

Histologic specimen of atypical carcinoid tumor demonstrating central necrosis.

Tissue section of LCNEC showing large pleomorphic cells, abundant cytoplasm, and peripheral palisading of nuclei.

Cytologic section of LCNEC showing much necrosis.

Positive synaptophysin immunocytochemical stain in LCNEC supporting the NE differentiation.