Clinicopathological features with outcomes of a series of conventional and proximal-type epithelioid sarcomas, diagnosed over a period of 10 years at a tertiary cancer hospital in India

Abstract

Epithelioid sarcoma (ES) is an uncommon sarcoma. Lately, its variants, including proximal-type ES, have been recognized. The present study highlights clinicopathological features of 26 (65%) conventional and 14 (35%) cases of proximal-type ES. Thirty-eight percent of cases were seen in 21-30-year age group, including 77.5% cases in men. Extremities were the commonest sites in both the subtypes. Histologically, conventional-type ES displayed nodular tumor aggregates with necrosis, while proximal-type showed solid arrangement of large, "rhabdoid-like" cells. More cases (64.2%) of the proximal type were of grade 3. A range of differential diagnoses was considered. Most important immunohistochemical markers were vimentin, epithelial membrane antigen, cytokeratin, CD34, and desmin. Maximum (72.5%) cases were treated surgically. Recurrences and metastasis were observed more in the proximal type. The 7-year disease-free survival was 19.4% in the conventional and nil in the proximal subtype (p = 0.06). The overall survival rate was also lower in the proximal (31.3%) than conventional type (90.2%; p < 0.001). Other unfavorable parameters were deeper location, larger size, and higher tumor stage. This unusual sarcoma, with characteristic growth patterns, merits a proper histological evaluation, as it has many mimics. Proximal-type ES is rather a morphological subtype, associated with an aggressive course.

Proximal-Type Epithelioid Sarcoma in the Groin Presenting as a Diagnostic Dilemma

“…The prognostic factors for this undifferentiated tumor are not yet clearly defined, as there have been very few small studies on this entity to date [14,20]. In the study by Hasegawa et al [14], tumor size was found to be an adverse prognostic factor; survival of patients whose neoplasms measured 7.8 cm or more being significantly shorter than those with smaller tumors.…”

“…Only 30% of the patients were alive at the last follow-up (2 months-9 years). In a recent comparative study between conventional ES (26 cases) and proximal-type ES (14 cases), Rekhi et al [20] found that the 7-year disease-free survival was 19.4% in the conventional ES and nil in the proximal subtype. The overall survival rate was also lower in the proximal ES (31.3%) than the conventional type (90.2%).…”

“…However, they did not find significant prognostic implications for other parameters such as patient age and sex, tumor depth, histologic subtype, vascular invasion, tumor necrosis, mitotic count, p53 expression and MIB-1 index . Rekhi et al [20] observed that deeper location, larger tumor size (more than 5 cm) and higher tumor stage had an adverse affect on the outcome. It is debatable whether the presence of 'rhabdoid' phenotype per se connotes a worse prognosis for this tumor [14,20,21].…”

“…Rekhi et al [20] observed that deeper location, larger tumor size (more than 5 cm) and higher tumor stage had an adverse affect on the outcome. It is debatable whether the presence of 'rhabdoid' phenotype per se connotes a worse prognosis for this tumor [14,20,21]. Further studies with fairly larger number of proximaltype ES are necessary to properly evaluate the prognostic impact of all these parameters.…”

“…Wide surgical excision, with clear resection margins remains the primary goal [1,14,20]. In a recent study, Livi et al [22] investigated the role of postoperative radiotherapy in 22 patients with ES.…”