Skip to main content

Table 2 Morphophenotypic features of the most common mesenchymal spindle cell neoplasms in the differential diagnosis of EESS

From: Primary extragenital endometrial stromal sarcoma of the lung: first reported case and review of literature

Mesenchymal Neoplasm Morphological features Immunohistochemical markers
Cellular leiomyoma/low-grade leiomyosarcoma characteristic intersecting fascicles of smooth muscle cigarshaped spindle cells with eosinophilic cytoplasm and perinuclear vacuolation, showing a smooth, pushing margin and large, irregular, thick-walled blood vessels muscle-specific actin +, smooth muscle actin +, desmin +, ER +, PgR+, CD10 −/+, H-caldesmon +
Gastrointestinal stromal tumor spindle cells with long tapering nuclei and abundant clear or eosinophilic cytoplasm arranged in fascicles or sheets; characteristically well circumscribed with pushing borders CD34 +, DOG-1 +, CD117 +, CD10 -, ER -, PgR-; muscle-specific actin −/+, smooth muscle actin −/+, desmin −/+,
Solitary fibrous tumor bland spindle cells haphazardly arranged in a dense collagenous matrix but lacks the peculiar characteristic vasculature of the ESS CD34 +, CD10 -, ER -, PgR-
Monophasic synovial sarcoma most commonly involves the soft tissues of the extremities; CD99 +, EMA +, CD10 -, ER -, PgR-
ESS monomorphous plump spindle cells forming short regular fascicles, evenly distributed arterioles and infiltrative border muscle-specific actin −/+, smooth muscle actin −/+, desmin −/+, ER +, PgR+, CD10 +, H-caldesmon -
  1. - negativity, −/+ focal positivity, + diffuse positivity, ER estrogen receptor, PgR Progesteron receptor, EMA epithelial membrane antigen