Although the age of the patient was atypical for a solitary fibrous tumor, it is among the less likely mediastinal masses.

As these tumors are rare, the diagnosis was histopathological.

HISTOPATHOLOGY

Microscopic examination
- Well circumscribed tumor composed of alternating hypocellular and hypercellular areas of bland looking spindle cells with abundunt ropy collagen bundles in between. Dilated vascular spaces are also seen. No atypia, mitosis or necrosis is seen. The tumor cells are immunopositive for CD34, C99 and BCL2 while are negative for SMA, desmin, EMA, S100 and CD5 immunohistochemical stains.

Diagnosis
- Solitary fibrous tumor.