Giant solitary fibrous tumor arising from greater omentum

Table 1 Laboratory findings on admission

Tumor markers	Index	Normal range
CA199 (KU/L)	5.47	< 35.00
CA242 (KU/L)	1.31	< 20.00
CA125 (KU/L)	2.27	< 35.00
CA15-3 (KU/L)	2.28	< 35.00
NSE (ng/mL)	< 1.0	< 13.00
CEA (ng/mL)	1.21	< 5.00
Ferritin (ng/mL)	27.13	< 322.00
β-HCG (MIU/mL)	< 0.02	< 3.00
AFP (ng/mL)	0.88	< 20.00
Free-PSA (ng/mL)	< 0.22	< 1.00
PSA (ng/mL)	< 0.04	< 5.00
HGH (ng/mL)	2.15	< 7.50

CA: Cancer antigen; NSE: Neuron-specific enolase; CEA: Carcinoembryonic antigen; β-HCG: β-human chorionic gonagotropin; AFP: Alphafetoprotein; PSA: Prostate specific antigen; HGH: Human growth hormone.

Table 2 Clinical characteristics of the 5 reported cases of solitary fibrous tumor originating from omentum

Ref.	Site	Age (yr)	Size (cm)	Weight (kg)	Immunohistochemical analysis (pos/neg)	Mitotic count	Local recurrence /metastases	Status at last follow-up
Salem et al[11]	Omentum	60	24 × 19 × 10	3.87	CD34, CD99/(SMA), desmin, CD117	25/10HPF	No	NED
								4 mo
Patriti et al[12]	Greater omentum	24	3.2 × 2.5	NA	CD34, bcl-2/Pan cytokeratin reaction	3/10HPF	No	NED
								2 yr
Mosquera et al[13]	Omentum	40	9	NA	CD34, CD99, p16/ EMA, cytokeratin, S-100, desmin, p53	9/10HPF	Yes	DOD
								34 mo
Ekıcı et al[14]	Lesser omentum	51	11.5 × 8.5 × 7.5	NA	CD 34/CD117, actin and S-100	0/10HPF	No	NED
								10 mo
Gold et al[15]	Omentum	NA	NA	NA	NA	NA	NA	NA

NA: Not available; Neg: Negative; Pos: Positive; NED: No evidence of disease; DOD: Dead of disease; HPF: High-power fields; EMA: Epithelial membrane antigen; SMA: Smooth muscle actin.

Table 3 Immunohistochemical indexes for differential diagnosis of mesenchymal tumors

	CD34	bcl-2	CD99	S-100	Cytokeratin	EMA	Calretinin	Desmin	α-SMA
Solitary fibrous tumor	+	+	+	-	-	-	-	±	±
Neurofibroma	+	+	-	+	-	-	-	-	-
Spindle cell lipoma	+	+	-	-	-	-	-	-	-
Synovial sarcoma	-	+	±	-	+	+	-	-	-
Desmoid tumor	-	-	-	-	-	-	-	+	+
Hemangiopericytoma	+	-	±	-	-	-	-	-	-
Malignant peripheral nerve sheath tumor	±	±	-	+	±	-	-	±	±
Sarcomatoid mesothelioma	-	±	±	-	+	+	+	-	-
Schwannoma	±	+	-	+	-	-	-	-	-
Calcifying fibrous pseudotumor	±	-	-	-	-	-	-	-	-
Smooth muscle tumor	±	±	±	-	-	-	-	+	+

α-SMA: α-smooth muscle actin; EMA: Epithelial membrane antigen.