Intrapulmonary solitary fibrous tumor

Introduction Solitary fibrous tumor is a neoplasm that arises most commonly from the pleura, but can occur at other sites. Intrapulmonary solitary fibrous tumor has been rarely reported and therefore is not well recognized. Case outline We report a case of an asymptomatic 63-year-old woman in whom a large, well-circumscribed mass was incidentally revealed on chest X-ray during preparation for ergometric cardiac testing. Chest computed tomography revealed an abnormal nodule in the lower right lung lobe. Mediastinal and hilar lymphadenopathy was not detected. After transthoracic fine needle aspiration, cytology showed a finding suspicious for spindle cell tumor. Consequently, right anterolateral thoracotomy with right lower lobectomy was performed. On gross examination, the lower right lobe was almost completely replaced with abnormal, white-yellow, well-demarcated solid nodule measuring 13.5 cm in its largest diameter surrounded by a pseudocapsule. After histological examination and applied immunohistochemical analysis, a diagnosis of intrapulmonary solitary fibrous tumor of low malignant potential was set. Due to the presence of unfavorable prognostic parameters (tumor size, as well as the presence of hypercellularity), more frequent follow-up check-ups were recommended. Eighteen months after surgery, the patient remained uneventful, with no evidence of tumor recurrence. Conclusion Intrapulmonary solitary fibrous tumor is a rare entity challenging for diagnosis, because variegated histology and variability of its growth patterns can resemble other soft tissue tumors. The treatment of choice is complete excision with clear surgical margins, but since morphology cannot be a reliable predictor of clinical behavior, the patients need a long-term follow-up.