This is largely a diagnosis of exclusion. Many tumours may show areas where the vasculature has a "pericytomatous" pattern, including solitary fibrous tumour, synovial sarcoma, infantile myofibromatosis, low-grade endometrial stromal tumour, mesenchymal chondrosarcoma, deep benign fibrous histiocytoma, myopericytoma and infantile fibrosarcoma. See the differential diagnosis of of spindle cell tumours of the pleura.
Immunohistochemistry
positive (intensity variable) |
|
50% of cases |
|
a few cases |
|
a few cases |
|
negative |
|
negative |
|
cytokeratin |
negative |
negative |
Insulin-like growth factor may be expressed: its diagnostic utility is being investigated.
Differential diagnosis
In particular, cases of metastatic haemangiopericytoma probably represetn one of the following:
meningeal haemangiopericytomas are the best established group
solitary fibrous tumour: so-called lipomatous haemangiopericytomas are CD34-positive and are probably a variant of solitary fibrous tumour.
most infantile haemangiopericytoma are now considered to be myofibromatosis1
orbital haemangiopericytoma overlaps with benign fibrous histiocytoma1
sinonasal haemangiopericytoma is probably a variant of glomus tumour1
mesenchymal chondrosarcoma
low-grade endometrial stromal sarcoma.
Prognosis
Soft tissue haemangiopericytomas: recurrence rate 22-50%, , metastases in up to 60%1
Meningeal haemangiopericytomas: recurrence in 60%, metastases in 23%1
References
Diagnostic histopathology of tumors. Edited by CDM Fletcher. 2nd edition. Churchill Livingstone. Page 77.
Diagnostic Immunohistochemistry edited by Professor D. J. Dabbs, pages 76
This page last revised 3.4.2003.
©SMUHT/PW Bishop