Sclerosing Epithelioid Fibrosarcoma

Abstract

Sclerosing epithelioid fibrosarcoma (SEF) is an uncommon tumor of deep soft tissues, originally described in 1995 by Meis-Kindblom et al. In the current study, the authors identified 16 cases of SEF in the pathology files of their institutions and studied their pathologic features and disease course. The group consisted of six male and 10 female patients (age range, 14-55 years; mean age, 40 years), and the tumors were located in a limb or limb girdle (n = 7), base of the penis (n = 1), back or chest wall (n = 3), and head and neck (n = 5). Tumor size ranged from 3.7 to 22 cm (mean, 8.9 cm). Histologically, the SEFs were composed predominantly of small to moderate-size round to ovoid, relatively uniform cells, often with clear cytoplasm, embedded in a hyalinized fibrous stroma. The only consistent immunohistochemical finding was a strong, diffuse reactivity of tumor cells for vimentin. Ultrastructural analysis performed in eight cases confirmed their fibroblastic nature. Bone invasion and tumor necrosis, features not reported before, were found in six cases each. Treatment consisted of intralesional excision (n = 2), attempted wide local excision (n = 11), and amputation (n = 3), with either adjuvant radiation therapy (n = 9) or chemotherapy (n = 3). Follow-up of at least 1 year in 14 cases revealed persistent disease or local recurrence in seven patients (50%), and distant metastasis in 12 patients (86%). Eight patients (57%) died of disease 16 to 86 months after diagnosis. Five patients were alive with disease as of last follow-up. SEF shares some pathologic features with two other fibrosing fibrosarcomas, low-grade fibromyxoid sarcoma and hyalinizing spindle cell tumor with giant rosettes, but in the authors' experience behaves clinically as a fully malignant sarcoma.

Sclerosing epithelioid fibrosarcoma metastasizing to the penile shaft

“…Due to the rarity of the disease and inconsistent reporting of both treatment techniques and followup, the ideal therapy is yet to be determined, with some showing no effect of radiation and chemotherapy. [1][2][3][4] We describe in this case a SEF presenting in the typical manner, mistaken as a benign lesion, and recurring at the site of primary excision. Along with this recurrence are suspicious subcentimetric pulmonary nodules, a common site of metastases, and a confirmed periurethral metastasis.…”

“…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.…”

“…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. [1][2][3] Distant metastases are most commonly reported to the lungs, with other sites including pleura and/or chest wall, kidney, stomach, bone, brain, pericardium, and lymph nodes. 1,3,13,14 Rates of metastases were originally reported as 43% with a median followup of 7.7 years.…”

“…2 One large systematic review of 90 patients revealed 83% had distant disease at a mean of three years post-diagnosis. In 67 patients with a mean followup of 3.8 years, 34% died from their disease, 35% were alive with disease, and 31% were disease-free.…”

An Update on the Application of Newly Described Immunohistochemical Markers in Soft Tissue Pathology

“…A subset of SEF has been shown to contain the FUS-CREB3L2 gene fusion or FUS gene rearrangements, characteristic of LGFMS. [74][75][76][77][78][79][80][81] Similar to LGFMS, strong diffuse cytoplasmic expression of MUC4 is seen in SEF, occurring in 69% (20 of 29) to up to 90% (9 of 10) of ''pure'' forms, and virtually all tumors (12 of 12) showing hybrid features of both LGFMS and SEF ( Figure 5). 82,83 Recent studies have shown that EWSR1-CREB3L1 is the predominant gene fusion in SEF; this fusion gene occurs uncommonly in LGFMS.…”