Fine needle aspiration biopsy of solitary fibrous tumor of the pleura. A report of two cases with a discussion of diagnostic pitfalls.

BACKGROUND

The diagnosis of a peripheral pulmonary nodule presents a challenge due to many diagnostic possibilities and pitfalls. We describe the cytologic features of solitary fibrous tumor of the pleura, differential diagnoses, pertinent immunohistochemical stains and histogenesis.

CASES

Two cases of solitary fibrous tumor of the pleura showed two cell populations on cytologic preparations; mesothelial cells and spindle cells. The neoplastic spindle cell component was positive for CD-34 and vimentin but not for cytokeratin.

CONCLUSION

Solitary fibrous tumor of the pleura is rare but should be included in the differential diagnosis of a peripheral pulmonary nodule. Fine needle aspiration biopsy is a safe and rapid method of providing a confirmatory diagnosis.