Aims: Primary localised pleural neoplasms are a rare group of thoracic tumours, with solitary fibrous tumour representing the most frequently encountered entity. Two cases of localised pleural neurofibromas involving the pleura are described.
Methods and results: The patients were both female: 78 and 29 years of age. In the former a pleural-based lesion was identified on a chest radiograph after she presented with shoulder pain. The second patient was known to have neurofibromatosis type I, and the pleural lesion was found incidentally during excision of a metastatic malignant peripheral nerve sheath tumour of the lung. Both tumours were localised and composed histologically of bland neoplastic spindle cells embedded in a loose collagenous matrix. There was variable immunoreactivity for S100 and CD34, while ultrastructure examination in the two cases showed a mixture of nerve sheath cell types.
Conclusion: To the best of the authors' knowledge, localised neurofibromas have not been previously reported within the pleura. The presence of a bland spindle cell pleural neoplasm immunoreactive for CD34 may potentially be mistaken for a solitary fibrous tumour. While distinction is usually achieved on close attention to the histological features, staining with S100 protein, especially in small biopsies, should be considered to exclude a neurofibroma.