Low power: DQ stain
Cellular smear with loosely cohesive cluster of epithelioid cells admixed with spindled cells
Medium power: DQ stain
Cluster of epithelioid cells with enlarged irregular nuclei
High power: DQ stain
Malignant cells in small clusters and singly dispersed
Medium power: Pap stain
Singly dispersed maliugnant cells with enlarged, irregular, eccentrically located nuclei, coarse chromatin, prominent nucleoli and pale to granular cytoplasm.
Note dirty necrotic background
Medium power: Pap stain
Cluster of epithelioid and spindled malignant cells with enlarged irregular nuclei
High power: Pap stain
Cluster of malignant cells with enlarged irregular pleomorphic nuclei with dense squamoid cytoplasm
Medium power: Pap stain
Malignant cells with enlarged irregular pleomorphic nuclei, often eccentrically located, prominent nucleoli,with plae cytoplasm. Note numerous giant cells with multinucleation
High power: Pap stain
Malignant multinucleated giant cells in a background of numerous singly dispersed plasmacytoid epithelioid maliganant cells
Features
• Cellular with highly malignant features
• Single cells and loosely cohesive clusters
• Epithelioid, spindled and giant cells
• Epithelioid cells may be plasmacytoid
• Pale to granular cytoplasm
• May have dense squamoid cytoplasm
• Nuclei enlarged, irregular contours
• Coarse chromatin
• Prominent nucleoli, macronucleoli
• Multinucleation
• Often has intranuclear cytoplasmic inclusions
• Dirty, necrotic background
• May have abundant neutrophils
• May have myxoid/ cartilageneous/ osseous metaplasia
• Typically rapidly enlarging highly malignant tumor
• May arise de novo or transformation of other thyroid carcinoma, typically papillary thyroid carcinoma
• May detect a more differentiated cytomorphology
• Cytokeratin +/- , vimentin may be positive ; typically negative for TTF-1, thyroglobulin, EMA, CEA
Us-Krasovec M et al.Acta Cytol. 1996 Sep-Oct;40(5):953-8.
Guarda LA et al. Diagn Cytopathol. 1991;7(1):63-7.