Soft tissue
Fibroblastic / myofibroblastic tumors
Sclerosing epithelioid fibrosarcoma (SEF)
Copyright: 2002-2018, PathologyOutlines.com, Inc.
PubMed Search: Sclerosing epithelioid fibrosarcoma [title]
Fibroblastic / myofibroblastic tumors
Sclerosing epithelioid fibrosarcoma (SEF)
Topic Completed: 1 June 2013
Minor changes: 14 December 2019
Copyright: 2002-2018, PathologyOutlines.com, Inc.
PubMed Search: Sclerosing epithelioid fibrosarcoma [title]
Table of Contents
Definition / general | Epidemiology | Sites | Clinical features | Prognostic factors | Case reports | Treatment | Gross description | Gross images | Microscopic (histologic) description | Microscopic (histologic) images | Cytology description | Positive stains | Negative stains | Electron microscopy description | Molecular / cytogenetics description | Differential diagnosisCite this page: Sullivan C. Sclerosing epithelioid fibrosarcoma (SEF). PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/softtissuesclerosingepithelioidfibrosarcoma.html. Accessed May 27th, 2020.
Definition / general
- Rare, slow growing, sarcoma of deep soft tissue with epithelioid tumor cells in nests and cords set in hyalinized fibrous stroma
- WHO Classification: Fibroblastic/Myofibroblastic Tumors
- First described in 1995 (Am J Surg Pathol 1995;19:979)
Epidemiology
- Mean age: 47 years (range 14 - 87 years)
- No gender preference (Clin Orthop Relat Res 2008;466:1485)
Sites
- Lower extremities / limb girdle (39%)
- Trunk (21%)
- Upper extremities (14.5%)
- Head and neck (14.5%)
- Abdominal / inguinal (11%) (Clin Orthop Relat Res 2008;466:1485)
Clinical features
- One third of cases present as painful and enlarging masses
- Deep-seated mass of muscle associated with fascia or periosteum
- Histologically low-grade but clinically aggressive
- Local recurrence in 50% (Am J Surg Pathol 2001;25:699, Am J Surg Pathol 1995;19:979)
- Distant metastases in 43% (Am J Surg Pathol 1995;19:979) to 86% (Am J Surg Pathol 2001;25:699); metastases are mostly commonly to lung, also skeleton, chest wall / pleura, pericardium, brain, scalp, breast, liver
- Prognosis at 46 months (Clin Orthop Relat Res 2008;466:1485):
- 34% - dead of disease
- 35% - alive with disease
- 31% - alive without disease
Prognostic factors
- Location appears to be linked to prognosis (Clin Orthop Relat Res 2008;466:1485):
- Head and neck - 46% dead of disease
- Upper extremity - 38% dead of disease
- Trunk - 26 % dead of disease
- No effect on prognosis:
- Gender - no effect on local recurrence
- Tumor size - metastatic disease independent of tumor size
Case reports
- 29 year old man with tumor related ascites (J Med Case Rep 2008;2:248)
- 30 year old man with metastatic disease (Sarcoma 2009;2009:953750)
- 39 year old man with primary liver tumor (World J Gastroenterol 2009;15:4204)
- 48 year old woman with sacral tumor (J Clin Pathol 2004;57:90)
- 54 year old woman with primary lung tumor (Lung 2012;190:691)
- 62 year old Chernobyl cleanup worker with cecal tumor (Arch Pathol Lab Med 2007;131:1825)
- 90 year old woman with ankle mass (Case of the Week #3)
Treatment
- Surgical resection (Clin Orthop Relat Res 2008;466:1485)
- Postoperative radiation commonly performed
- Chemotherapy less common
Gross description
- Mean size: 9 cm (range 4 - 22 cm)
- Grossly well circumscribed
- Lobulated, bosselated, or multinodular
- Firm, gray-white cut surface, occasionally cystic, calcified, myxoid
- May invade bone
- Usually no necrosis
Gross images
Images hosted on PathOut servers:
Courtesy of Mark R. Wick, M.D.
Images hosted on other servers:
Lobulaulated, multinodular white mass
Microscopic (histologic) description
- Low power: hypocellular tumor with large areas of hyalinized fibrous stroma
- Mid power: nests and cords of small to medium sized, round to ovoid, relatively uniform epithelioid cells; some tumors have a more alveolar pattern; may have areas resembling fibroma, low grade fibromyxoid sarcoma, conventional fibrosarcoma; occasionally tumors have hemangiopericytoma-like vasculature, vascular invasion, necrosis (Histopathology 1998;33:354)
- High power: often clear to scant eosinophilic cytoplasm and uniform bland nuclei with vesicular or finely stipple chromatin and small basophilic nucleoli; mitoses are inconspicuous, < 4 MF / 10 HPF
Microscopic (histologic) images
Images hosted on PathOut servers:
Courtesy of Mark R. Wick, M.D.
Images hosted on other servers:
Epithelioid cells with clear cytoplasm
Cords of epithelioid cells within a eosinophilic hyalinized stroma
Alveolar pattern
Epithelioid cells in a densely collagenized matrix
Hemangioper-
icytoma-like vascular pattern
Resemblance to carcinoma
Cytology description
- Only one case report (Diagn Cytopathol 2010;38:748): clusters of moderately overcrowded epithelioid cells with background of histiocytes and lymphocytes and a few mesothelial cells
- Nuclei eccentrically placed and pleomorphic with oval, spindled, or cleaved shape
- Uniformly fine, granular chromatin and thin nuclear membrane
- Numerous small nucleoli
- Occasional multinucleated cells
Positive stains
Electron microscopy description
- Fibroblastic features with rough endoplasmic reticulum, pinocytotic vesicles, well-developed Golgi apparatus, and a moderate amount of mitochondria and intermediate filaments (Cancer Genet Cytogenet 2000;119:127, Pathol Int 2002;52:135)
Molecular / cytogenetics description
- May be related to low grade fibromyxoid sarcoma, because same FUS-CREB3L2 translocation is detectable in a subset of cases (Am J Surg Pathol 2007;31:1387, Mod Pathol 2012;25:846, Pathol Oncol Res 2011;17:145, Am J Surg Pathol 2007;31:1387)
Differential diagnosis
- Hyalinizing spindle cell tumor with giant rosettes: histologic subtype of low grade fibromyxoid sarcoma with similar features plus collagen rosettes (Ann Diagn Pathol 2011;15:303, may be related to SEF)
- Lobular breast carcinoma: single file pattern, but cells are low grade; usually ER+, PR+, keratin+
- Low-grade fibromyxoid sarcoma: monotonous bland nuclei, alternating hyper and hypocellular areas, with alternating myxoid and collagenous stroma, only focal epithelioid cells; most contain FUS-CREB3L2 translocation (may be related to SEF)
- Poorly differentiated carcinoma: positive for keratin
- Sclerosing lymphoma: positive for lymphocytic markers, such as LCA / CD45
- Synovial sarcoma: more cellular, lacks large areas of hypocellular sclerotic collagen; t(X;18) positive
