Sinonasal-type haemangiopericytoma

About 15% of haemangiopericytomas occur in the head or neck6. Sinonasal haemangiopericytoma show differences in the immunoreactivity of the neoplastic cells from those of haemangiopericytoma at the more common soft tissue sites and meningeal haemangiopericytoma, but closer to the profile of glomus tumours2 with evidence of myoid differentiation (expressing actin but not desmin). An alternative interpretation is that sinonasal haemangiopericytoma is the only adult haemangiopericytoma showing true pericytic differentiation5. They are probably distinct from myopericytoma.

Clinical features.

Most patients are middle-aged or elderly. The nasal cavity or paranasal sinuses are the most common sites, although they may occur elsewhere in the head and neck.

Macroscopic appearance

The tumour is often polypoidal, without surface ulceration6.

Histopathology

This is an intramucosal tumour, usually separated by a thin tumour-free zone from the intact surface epithelium, which often has a thickened basement membrane. The margins are pushing and usually well-demarcated but the tumour is not encapsulated. The tumour cells are uniform, short spindly or cuboidal, with eosinophilic cytoplasm and oval nuclei and fine chromatin with small nucleoli. Cell membranes are indistinct. The tumour cells may form a pattern that is fascicular, storiform, whorled, meningothelial-like, palisaded, reticular or mixed, but there are not long fascilces. There is a rich vasculature which varies from slit-like sinusoids, small capillaries to ectatic vessels, including staghorn vessels. Perivascular hyalinisation is characteristic. Tumour giant cells may be present, with the same immunoprofile as the other tumour cells, and are unique to sinonasal haemangiopericytoma (but similar to those seen in symplastic glomus tumours)6. The mitotic rate is usually less than 1 /10 HPF. Reticulin fibres envelop each cell. Most cases include an inflammatory infiltrate of mast cells and eosinophils6.

Rarely, there may be juxtaposed solitary fibrous tumour or lipomatous haemangiopericytoma6. Occasional cases show sufficient atypia to be diagnosed as malignant haemangiopericytoma.

Immunohistochemistry

Ultrastructure

The most consistent features were basal lamina-like material partly surrounding tumor cells and completely separating them from endothelium, tapered cytoplasmic extensions, and orderly bundles of actin-like thin filaments4. Intercellular junctions and pinocytotic vesicles were present in some tumours3.

Differential diagnosis

• lobular capillary haemangioma: there is a lobular growth pattern with a granulation tissue-like appearance. Perivascular hyalinisation is lacking.

• glomus tumour

• solitary fibrous tumour: also shows a perivascular pattern and positivity for CD34. There is ropey keloidal collagen. There is diffuse positivity for CD34, bcl-2 and CD99, but negativity for actin and desmin.

• other sarcomas with a haemangiopericytomatous pattern

Prognosis

Sinonasal haemangiopericytomas show a much lower malignant potential than do other haemangiopericytomas. Of nine cases with adequate follow-up, tumors recurred in four cases after a mean of 6.5 years, and none metastasized2. A review of the literature showed that high local recurrence rates (7% to 40%), late recurrences, and low rates of metastasis were features of tumors in this location. This might be a reflection of early presentation, small tumor bulk, and difficulty of complete resection, rather than evidence for a biologically distinct neoplasm3.

References

1Kapadia SK et al. Sinonasal hemangiopericytoma. Mod Pathol 1993;6:81A (abstract).

2Tse, L.L. and Chan, J.K. Sinonasal haemangiopericytoma-like tumour: a sinonasal glomus tumour or a haemangiopericytoma? Histopathology 2002;40:510-7.

3Eichhorn, J.H., Dickersin, G.R., Bhan, A.K. and Goodman, M.L. Sinonasal hemangiopericytoma. A reassessment with electron microscopy, immunohistochemistry, and long-term follow-up. Am J Surg Pathol 1990;14:856-66.

4Perez-Ordonex B. Special tumours of the head and neck. Current Diagnostic Pathology 2003;9:366-383.

5Watanabe, K., A. Saito, et al. (2001). "True hemangiopericytoma of the nasal cavity." Arch Pathol Lab Med 125(5): 686-90.

6Thompson, L. D., M. Miettinen, et al. (2003). "Sinonasal-type hemangiopericytoma: a clinicopathologic and immunophenotypic analysis of 104 cases showing perivascular myoid differentiation." Am J Surg Pathol 27(6): 737-49.

This page last revised 17.2.2004.

©SMUHT/PW Bishop