Proximal-type epithelioid sarcoma: A clinicopathologic study of 20 cases

T. Hasegawa et al., Proximal-type epithelioid sarcoma: A clinicopathologic study of 20 cases, MOD PATHOL, 14(7), 2001, pp. 655-663
Citations number
Categorie Soggetti
Research/Laboratory Medicine & Medical Tecnology","Medical Research Diagnosis & Treatment
Journal title
ISSN journal
0893-3952 → ACNP
Year of publication
655 - 663
SICI code
We studied the clinicopathologic and immunohistochemical features of 20 cas es of proximal-type epithelioid sarcoma to identify prognostic factors. The 20 patients ranged in age from 13 to 80 years (mean, 40 y); 12 patients we re male and 8 were female. The tumors presented as deep soft-tissue or subc utaneous masses on the inguinal region in five, the thigh in four, the vulv a in three, the axilla in three, and one each in the flank, chest wall, bac k, hip and perineum. The tumors ranged from 2 to 16 cm at their greatest di ameter (mean: 7.8 cm). Histologically, 12 tumors (60%) were classified as t he large-cell subtype, characterized by sheets of large cells with prominen t nucleoli resembling poorly differentiated carcinoma, and a frequent rhabd oid phenotype, six (30%) were classified as the conventional subtype, and t wo (10%) as the angiomatoid subtype. The numbers of tumors exhibiting immun oreactivity for various markers were: vimentin (20 cytokeratin (20 [100%]); epithelial membrane antigen (17 [85%]); CD34 (9 [45%]); CD99 (5 [25%]); mu scle markers, either desmin or alpha -smooth muscle actin (3 [15%]), other markers such as S-100 protein, neurofilament, neuron-specific enolase, syna ptophysin and CD56 (12 [60%]); and p53 (16 [80%]). Fourteen lesions (70%) e xhibited an MIB-1 index of 30% or more and, by a system of histologic gradi ng using the MIB-1 score, 16 tumors (80%) were classified as high-grade (Gr ade 3). Thirteen patients (65%) developed local recurrence and 15 (75%) had metastases, primarily to the lymph nodes. At the last follow-up, 13 patien ts (65%) had died of their disease. A large tumor size and early metastasis were independently associated with a poor outcome. We conclude that proxim al-type epithelioid sarcomas are rare, undifferentiated soft-tissue sarcoma s of adults, with epithelioid features and a frequent rhabdoid phenotype. T hese tumors, when arising in proximal locations, have a much worse prognosi s than those arising in distal locations.