Sclerosing Epithelioid Fibrosarcoma of the Jaw: Late Recurrence from a Low Grade Fibromyxoid Sarcoma

Abstract

Sclerosing epithelioid fibrosarcoma (SEF) is an uncommon variant of fibrosarcoma that is characterized by a distinct morphology. It most frequently presents in the deep soft tissues of the lower extremities, often in intimate association with fascia and periosteum, although reports of the head and neck involvement have been reported. A minority of cases show morphological, immunohistochemical and molecular overlap with low grade fibromyxoid sarcoma (LG-FMS). Herein, we describe a case of a bland spindle cell neoplasm presenting in the jaw that was initially incompletely excised. Over the course of 20 years the tumor subsequently recurred with a SEF morphology. Molecular testing performed on both specimens subsequently confirmed the presence of an EWSR1-CREB3L1 gene fusion. This report highlights the diagnostic difficulty with LG-FMS, particularly in unusual anatomic locations; reiterates the potential for the uncommon EWSR1-CREB3L1 fusion product in LG-FMS; and, reaffirms the potential for progression and/or overlap between LG-FMS to SEF over time.

Clinical and molecular characterization of primary sclerosing epithelioid fibrosarcoma of bone and review of the literature

“…1 A pathogenetic link with low grade fibromyxoid sarcoma (LGFMS) has been suggested, due to cases with hybrid morphology as well as overlapping genetic signature. [4][5][6][7][8][9][10] Only in a handful of these reports, the presence of EWSR1 [4][5][6][7][8][9][10] Only in a handful of these reports, the presence of EWSR1…”

“…4,8,10 Triggered by three consecutive cases of primary skeletal SEF which were misdiagnosed as tumors that more often occur in the bone, ranging from "atypical chondroblastoma," small cell osteosarcoma and Ewing sarcoma, we reviewed our files for cases that fit with this clinical presentation. 4,8,10 Triggered by three consecutive cases of primary skeletal SEF which were misdiagnosed as tumors that more often occur in the bone, ranging from "atypical chondroblastoma," small cell osteosarcoma and Ewing sarcoma, we reviewed our files for cases that fit with this clinical presentation.…”

“…2,3 Most cases occur in the deep soft tissues, but rare cases have been reported to arise in bone. [4][5][6][7][8][9][10] Only in a handful of these reports, the presence of EWSR1 or FUS gene rearrangements has been documented. 4,8,10 Triggered by three consecutive cases of primary skeletal SEF which were misdiagnosed as tumors that more often occur in the bone, ranging from "atypical chondroblastoma," small cell osteosarcoma and Ewing sarcoma, we reviewed our files for cases that fit with this clinical presentation.…”

“…A pathogenetic link with low grade fibromyxoid sarcoma (LGFMS) has been suggested, due to cases with hybrid morphology as well as overlapping genetic signature . Most cases occur in the deep soft tissues, but rare cases have been reported to arise in bone . Only in a handful of these reports, the presence of EWSR1 or FUS gene rearrangements has been documented .…”

Case Report: Radiological Features of Sclerosing Epithelioid Fibrosarcoma in the Right Fibula

“…It has been reported to have relatively high incidence of local recurrence (>50% of cases), metastasis (40-80% of cases) and tumor-related mortality (2,3). SEF typically involves the extremities or the torso (2), followed by the abdominal viscera (4,5) and head and neck areas (6)(7)(8). Primary SEF in the bone was first reported in 2001 (9).…”