The fibroma-like variant of epithelioid sarcoma. A fibrohistiocytic/myoid cell lesion often confused with benign and malignant spindle cell tumors.
Five cases of a previously undescribed variant of epithelioid sarcoma are presented. This variant differs from the usual lesion in its absence of the typical necrobiotic nodular epithelioid pattern. It is instead composed of deceptively bland fibrohistiocytic and myoid cells arranged in a fibroma-like or dermatofibroma-like pattern with an affinity for osseous involvement. The clinical presentation, ultrastructural features, and presence of vimentin and low molecular weight keratin within the tumor cells justifies their designation as an epithelioid sarcoma variant.
Division of Orthopedic Oncology, Hospital of The Good Samaritan, Los Angeles, CA 90024.
J M
JM
Mirra
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S
Kessler
S
S
Bhuta
J
J
Eckardt
D000293:Adolescent; D000328:Adult; D001859:Bone Neoplasms / Q000737:chemistry / Q000473:pathology*; D002111:Calcaneus / Q000473:pathology; D003937:Diagnosis, Differential; D005260:Female; D005266:Femoral Neoplasms / Q000473:pathology; D005350:Fibroma / Q000473:pathology; D005385:Fingers / Q000473:pathology; D018219:Histiocytoma, Benign Fibrous / Q000473:pathology; D006801:Humans; D006811:Humerus / Q000473:pathology; D007633:Keratins / Q000032:analysis; D008297:Male; D009364:Neoplasm Recurrence, Local / Q000473:pathology; D009378:Neoplasms, Multiple Primary / Q000473:pathology; D012509:Sarcoma / Q000737:chemistry / Q000473:pathology*; D012878:Skin Neoplasms / Q000737:chemistry / Q000473:pathology*; D012983:Soft Tissue Neoplasms / Q000737:chemistry / Q000473:pathology*; D013848:Thigh / Q000473:pathology; D013977:Tibia / Q000473:pathology; D014034:Toes / Q000473:pathology; D014457:Ulna / Q000473:pathology; D014746:Vimentin / Q000032:analysis
D014746:Vimentin; D007633:Keratins