Sclerosing Epithelioid Fibrosarcoma of the Bone: A Case Report of High Resistance to Chemotherapy and a Survey of the Literature

Abstract

Sclerosing epithelioid fibrosarcoma (SEF) is a rare soft tissue sarcoma mostly occurring in extraosseous sites. SEF represents a clinically challenging entity especially because no standardized treatment regimens are available. Intraosseous localization is an additional challenge with respect to the therapeutical approach. We report on a 16-year-old patient with SEF of the right proximal tibia. The patient underwent standardized neoadjuvant chemotherapy analogous to the EURAMOS-1 protocol for the treatment of osteosarcoma followed by tumor resection and endoprosthetic reconstruction. Histopathological analysis of the resected tumor showed >90% vital tumor cells suggesting no response to chemotherapy. Therefore, therapy was reassigned to the CWS 2002 High-Risk protocol for the treatment of soft tissue sarcoma. To date (22 months after diagnosis), there is no evidence of relapse or metastasis. Our data suggest that SEF may be resistant to a chemotherapy regimen containing Cisplatin, Doxorubicin, and Methotrexate, which should be considered in planning treatment for patients with SEF.

Sclerosing Epithelioid Fibrosarcoma – A Rare Sacral Lesion and Literature Review

“…Osteosarcoma can be suggested by a higher prevalence, age of diagnosis, and radiographic appearance [12]. Regarding the location, SEFs mainly present as tumours of the lower extremities (39%), followed by the trunk (21%) and upper extremities (14.5%) [16]. The thigh is the most common location for soft tissue sarcoma [1].…”

“…This is particularly difficult to the diagnosis on visceral organs because of its rarity and its epithelioid appearance, closely mimicking carcinomas [18]. A strong and diffuse cytoplasmic reactivity for vimentin is a characteristic feature of sclerosing epithelioid fibrosarcoma, and 70% of the cases show MUC4 positivity [7,14,16,17]. It lacks immunoreactivity for epithelial membrane antigen; cytokeratins (CAM5.2 or AE1/3), HMB-45, neuronspecific enolase, desmin, smooth muscle actin, or muscle common actin (HHF-35) [8] Focal and weak immunostaining for EMA, S-100 protein and more rarely for cytokeratins may be seen in a minority of cases [19].…”

“…The first marker is important to another entity that was essential to exclude, the low-grade fibromyxoid sarcoma (LGFMS). Due to a subset of overlapping morphologic and immunohistochemical features, related members in the fibroblastic family, both display hyalinized spindle cell tumours with giant rosetes [7,16,17,20].…”

“…Regarding bone relation, an option is to plan neoadjuvant chemotherapy treatment, based on the EURAMOS-1 protocol [16]. It consists of chemotherapy elements with Doxorubicin, Cisplatin, and high-dose Methotrexate [24].…”

Sclerosing epithelioid fibrosarcoma metastasizing to the penile shaft

“…1 Other primary sites have been described in the literature, including the pituitary gland, oral cavity, lung, bone, intra-abdominal, liver, pancreas, cecum, ovary, penis, and neuraxis. [2][3][4][5][6][7][8][9][10][11][12][13] Despite being histologically low-grade, SEF has a high local recurrence rate. Originally reported as a rate of 53% at a median followup of 4.8 years, variable rates (30-50%) have been described due to inconsistent reporting of followup.…”