An Unexpected Finding of an Aggressive Pleural Hemangiopericytoma/Solitary Fibrous Tumor in a Patient With Recurrent Meningioma: A Case Report.

Pleural hemangiopericytoma/solitary fibrous tumor (HPC/SFT) is a rare form of mesenchymal tumor arising from pericytes, which predominantly occurs intrathoracically. HPC/SFT can be suspected on imaging, but radiographic features are non-specific. Therefore, histological confirmation remains the gold standard. Due to the rarity of the tumor, specific anatomical pathological expertise is necessary to make the diagnosis, which is not available in every hospital. Here, we report the case of a 51-year-old female with a medical history of recurrent meningiomas. A chest CT scan revealed extensive subpleural soft tissue lesions in the left hemithorax with histological characteristics suggestive of a pleural malignancy. A specialized analysis of the sample led to the final diagnosis of HPC/SFT. Unfortunately, in the meantime, the patient's condition worsened rapidly, and she passed away before the final diagnosis was made and any decisions about therapeutic options were taken. In our case, we want to highlight the importance of having knowledge about the existence of this type of tumor in order to make the correct diagnosis in a timely manner.