Table 2.

Comparison of histological features among conventional LMS, epithelioid LMS, and myxoid LMS.

Histologic Features	Conventional LMS	Epithelioid LMS	Myxoid LMS
Essential diagnostic criteria
	(2 of 3 histologic features):	(≥1 feature):	(≥1 feature):
Cytologic Atypia	Severe	Moderate to severe	Moderate to severe
Necrosis	Present	Present	Coagulative necrosis
Mitosis	≥10 mitoses/10 high power fields	often about 3 mitoses/10 high power fields	often about 3 mitosis/10 high power fields
Margins	infiltrative border	infiltrative borders	infiltrative borders
Cytologic features
Cell type	Spindle/elongated	>50% round or polygonal
Cytoplasm	Eosinophilic	Eosinophilic, extensive hyalinization	scant
Nucleus	Hyperchromatic/pleomorphic Multinucleated Atypical mitoses	mild nuclear atypia	nuclear pleomorphism
Growth pattern
	Cellular tumor comprised of long intersecting or haphazard fascicles	Arranged in nests, cords, or sheets May show pseudo-glandular spaces	Hypocellular tumor with abundant myxoid stroma Myxoid stroma may be difficult to differentiate from hydropic change in small/limited samples