44. Intrapulmonary solitary fibrous tumour

Background Solitary fibrous tumour is a neoplasm that arises most commonly from the pleura but can occur in other sites. Intrapulmonary solitary fibrous tumour has been rarely reported and hence limited data is available. It is suggested that the sub-pleural mesenchyme is continuous with that of the interlobular septa, which can therefore give rise to intrapulmonary lesions. Surgical resection with clear margins remains the gold standard of treatment even for low grade tumours. Case presentation A 71-year-old female with a background history of invasive lobular breast carcinoma and malignant melanoma was incidentally found to have a right lower lobe lung mass increasing in size over a two year period. PET scan demonstrated low-grade metabolic activity. Blood tests, including a full blood count, urea and electrolytes and liver function tests were all within normal limits. She proceeded to surgery and an intra-operative assessment was performed. A wedge of lung was received, containing a nodular mass measuring 28 mm across. The frozen section diagnosis of a mesenchymal neoplasm, including solitary fibrous tumour was considered. The margins were involved and hence a further intra-operative margin clearance was performed. Permanent sections confirmed the diagnosis of intrapulmonary solitary fibrous tumour by morphology and immunohistochemistry. Conclusion Intrapulmonary solitary fibrous tumour is a rare neoplasm. It is important to consider it as part of the differential diagnoses during intra-operative assessment to guide surgical management. Adequacy of margins is an important indicator of clinical behaviour. Even with successful surgery, long-term follow up is recommended to detect recurrent disease.