Difference between revisions of "Solitary fibrous tumour"

[[File:3 18039322534203 sl 3.png|malignant solitary fibrous tumor]]

[[File:3 18039322534203 sl 3.png|malignant solitary fibrous tumor]]

[[File:3 18039322534203 sl 4.png|malignant solitary fibrous tumor]]

[[File:3 18039322534203 sl 4.png|malignant solitary fibrous tumor]]

Malignant solitary fibrous tumor (low to intermediate grade tumor). 15 cm mass in upper arm of 50 year old man. A. Hypocellular (green arrow) and hypercellular (cyan arrow) areas alternate.  B. Vascular spaces suggest antlers (staghorn). Note subcapsular hemorrhage.  C. Stromal hyalinization.  D. Nuclei, lacking organization, show varied size and shape, with some cells being round to ovoid. The arrow points to myxoid focus in stroma. When a majority of the following are present, a low to intermediate grade malignant solitary fibrous tumor is present: 1) size > 5 cm (this case), 2) pleomorphism with round cells/epithelioid cells (this case), 3) subcapsular hemorrhage (this case), 4) ≥4 mitoses per 10 high power fields, 5) necrosis with perivascular tumor sparing. STAT 6 positivity is very helpful in separating this tumor from its mimics. Am J Surg Pathol 2014;38:552-559

Malignant solitary fibrous tumor (low to intermediate grade tumor). 15 cm mass in upper arm of 50 year old man. A. Hypocellular (green arrow) and hypercellular (cyan arrow) areas alternate.  B. Vascular spaces suggest antlers (staghorn). Note subcapsular hemorrhage.  C. Stromal hyalinization.  D. Nuclei, lacking organization, show varied size and shape, with some cells being round to ovoid. The arrow points to myxoid focus in stroma. When a majority of the following are present, a low to intermediate grade malignant solitary fibrous tumor is present: 1) size > 5 cm (this case), 2) pleomorphism with round cells/epithelioid cells (this case), 3) subcapsular hemorrhage (this case), 4) ≥4 mitoses per 10 high power fields, 5) necrosis with perivascular tumor sparing. STAT 6 positivity is very helpful in separating this tumor from its mimics. Am J Surg Pathol 2014;38:552-559