Clinicopathological analysis of extraneural sporadic haemangioblastoma occurring in the tongue

Abstract

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.

Keywords: Oral and maxillofacial surgery; Pathology.

Figure 1

CT: The lesion on the left side of the tongue (red arrow) demonstrates slightly low density on non-contrast CT scan (A) and significantly enhanced on arterial phase CT scan (B), which measures about 46×39 mm.

Figure 2

Macroscopic features: the excised tissue specimen measured 5.5×4×3 cm in size with uneven surface and locally presented nodular appearance. The cut surface of the mass was well-circumscribed, partly cystic, slightly tough and grey-red in colour.

Figure 3

Histological features: (A) the tumour was surrounded by a thick fibrous capsule and had a clear boundary (HE×40). (B, C) The tumour was composed of numerous blood vessels which varied from small capillaries to medium-sized vessels and stromal cells (HE×100). (D, E) The stromal cells were oval to polygonal with eosinophilic or vacuolated cytoplasm, and locally contained lipid droplets but no hyaline globules (HE×100). (F) The nuclei of these stromal cells varied in size, with mild to moderate atypical and hyperchromatic features (HE×400). (G) Nucleolus could be found in the stromal cells but mitotic figures were scarce (HE×400). (H) focal intratumoural haemorrhage was seen (HE×200).

Figure 4

Immunohistochemical staining: tumour cells were positive for CD56 (A×200), NSE (B×200), S-100 protein (C×200), EMA (D×200), vimentin (E×200), Fli-1 (F×200). Ki-67 expression was approximately 3% of tumours (G×100). CD34 staining outlined the capillary network of the tumour vasculature (H×100).