Sheets and nests of epithelioid cells
Pale amphophilic cytoplasm
Round-ovoid nuclei with macronucleoli, vesicular chromatin, and mild pleomorphism; conspicuous mitotic activity
IHC: epithelial membrane antigen, INI-1
Infiltrative; fascicles of spindle cells
Pale amphophilic cytoplasm
Ovoid nuclei with prominent nucleoli and moderate pleomorphism; mitotic activity
Focal necrosis
IHC: CD34, keratin (AE1/AE3), INI-1
Lobulated; fascicles of spindle-polygonal cells
Eosinophilic cytoplasm
Ovoid nuclei with vesicular chromatin, prominent nucleoli and moderate pleomorphism; inconspicuous mitotic activity
Delicate collagenous stroma
IHC: keratin (AE1/AE3), INI-1
Lobulated; sheets and nests of epithelioid cells
Pale amphophilic cytoplasm
Round-ovoid nuclei with macronucleoli, vesicular chromatin and mild pleomorphism; conspicuous mitotic activity
Focal necrosis
IHC: keratin (AE1/AE3), INI-1
Sheets and nests of epithelioid cells
Amphophilic cytoplasm
Round-ovoid nuclei with occasional clefts, prominent nucleoli, and mild pleomorphism; mitotic activity
IHC: keratin (AE1/AE3), INI-1
Sheets and nests of epithelioid cells
Pale amphophilic cytoplasm
Round-ovoid nuclei with macronucleoli, vesicular chromatin and mild pleomorphism; mitotic activity
Focal necrosis
IHC: INI-1
Sheets and nests of epithelioid cells
Pale amphophilic cytoplasm
Round-ovoid nuclei with macronucleoli, vesicular chromatin and mild pleomorphism; conspicuous mitotic activity
Focal necrosis
IHC: INI-1