Low power: DQ stain
Cellular smear with small clusters of medullary carcinoma cells
Medium power: DQ stain
Spindle cells admixed with plasmacytoid cells, singly dispersed and in small clusters
Low power: DQ stain
Predominantly single cells with plasmacytoid appearance
Note variation of nuclear size commonly seen in neuroendocrine tumors
High power: DQ stain
Dispersed plasmacytoid cells with round eccentrically located nuclei and granular cytoplasm
Low power: Pap stain
Cellular smear with syncticial aggregates and single cells in the background
Medium power: Pap stain
Predominantly singly dispersed cells with plasmacytoid features admixed with spindle cells
Medium power: Pap stain
Singly dispersed and small clusters of plasmacytoid cells with round nuclei, variation in nuclear size, occasional binucleation and salt and pepper chromatin
Medium power: Pap stain
Singly dispersed and clusters of spindled and plasmacytoid cells with salt and pepper chromatin and granular cytoplasm
High power: Pap stain
Cluster of spindled cells with elongated nuclei, salt and pepper chromatin and granular cytoplasm
High power: Pap stain
Singly dispersed and clusters of spindled cells with elongated nuclei, salt and pepper chromatin and granular cytoplasm
High power: Pap stain
Singly dispersed and small clusters of plasmacytoid cells with round nuclei, occasional binucleation and salt and pepper chromatin and granular cytoplasm
Features
• Cellular smears
• Different patterns hence mimicker
• Single cells, clusters, syncitial groups, microfollicles, sheets, papillae
• Plasmacytoid, spindled, or atypical bizarre multinucleated
• Neuroendocrine• like features
• Finely granular cytoplasm
• May have cytoplasmic neurosecretory granules (metachromatic)
• May have dendritic cytoplasmic processes
• May have intracytoplasmic vacuoles
• Nuclei round, frequently eccentrically located
• Spindle cells with elongated nuclei
• Bi/multinucleation commonly seen
• Nucleoli visible to prominent
• Intranuclear cytoplasmic inclusions often seen
• Amyloid (dense and fibrillary) metachromatic on DQ stain
• Absent to scant colloid
• Express cytokeratin, synaptophysin, chromogranin, NSE, CEA, Calcitonin, TTF-1, thyroglobulin +/- , Pax-8 +/-
Collins BT et al. Acta Cytol. 1995 Sep-Oct;39(5):920-30.
Zeppa P et al. Cytopathology. 1990;1(1):35-44.