Low power: DQ stain
Small acinar group of large malignant cells in a background of necrosis, naked nuclei and inflammation
High power: DQ stain
Malignant cells with enlarged irregular nuclei and moderate to abundant vacuolated cytoplasm
Low power: Pap stain
Small clusters of malignant cells in a background of naked nuclei and inflammation
Medium power: Pap stain
Malignant cells with enlarged irregular nuclei, coarse chromatin, prominent to multiple small nucleoli and moderate to abundant vacuolated cytoplasm
Note single cells and inflammation in the background
High power: Pap stain
Malignant cells with enlarged pleomorphic nuclei, coarse chromatin, prominent to multiple small nucleoli and moderate to abundant vacuolated cytoplasm
Note intracytoplasmic mucin vacuole
High power: Pap stain
Poorly differentiated adenocarcinoma cells with enlarged irregular pleomorphic nuclei, coarse chromatin, prominent to multiple small nucleoli and moderate to abundant vacuolated cytoplasm
Features
Cellular smears with crowded cells
3D clusters, acinar/ papillary formation, single cells
• High N:C ratio
• May have columnar morphology
• Vacuolated delicate to granular cytoplasm
• Mucin vacuoles may be present
• Nuclear atypia increases with less differentiated tumors
• Nuclei enlarged, irregular to pleomorphic
• Coarse chromatin
• Prominent nucleoli
• Inflammation may be present
• Necrosis often present
• Express cytokeratin, CK7, villin +/- , CDX2 +/- , may express CK20, negative for TTF-1, GCDFP-15