Solitary fibrous tumours of the head and neck region are
extremely rare. The clinical diagnosis is often difficult to
establish, and this lesion may be indistinguishable from other
soft tissue neoplasms. An 18-year old Chinese gentleman
presented with a painless right submandibular swelling which
was increasing in size for eight months. A computed
tomography scan showed a well-defined solid mass measuring
about 2.0 x 2.96 cm in the submandibular region. The tumour
was resected and was confined within its capsule.
Immunohistochemical staining was strongly positive for CD34,
CD 99, and vimentin and negative for desmin, smooth muscle
actin (SMA), cytokeratin, S100 and CD68. The microscopic and
immunohistochemical profile were compatible with solitary
fibrous tumour. Distinguishing solitary fibrous tumours from
various spindle neoplasms can be difficult. In view of the
resemblance, immunohistochemical staining can help
differentiate solitary fibrous tumour from spindle neoplasm.