Clinicopathological analysis of extraneural sporadic haemangioblastoma occurring in the tongue.

Haemangioblastoma is a morphologically distinctive tumour with uncertain histogenesis, typically occurring in the cerebellum, brain stem or spinal cord and less commonly in extraneural locations. Here, we present a case of haemangioblastoma occurring in the tongue, which is the first reported case in terms of the pathogenic site. The tumour was morphologically indistinguishable from central nervous system haemangioblastoma, that is, neoplastic stromal cells with cytoplasmic vacuolisation and abundant small vessels. Immunohistochemical studies revealed that the tumour cells were positive for S100, NSE, CD56, Syn, EMA, vimentin and α-inhibin, while negative for CK, SMA, factor Ⅷ, D2-40 and GFAP. Immunostainings for CD34 and CD31 outlined the rich and delicate vascular channels. Ki-67 expression was presented in approximately 3% of tumour cells. Primary haemangioblastoma has not been previously described at this site, and this case emphasises the need to consider haemangioblastoma in the differential diagnoses of neoplasms occurring in the tongue.