Solitary fibrous tumor: clinicopathological study of 16 cases

Background: Solitary fibrous tumor (SFT) is a localized fibrous mesothelioma and was originally described as a benign pleural lesion. It is a mesenchymatous lesion that has been found in different structures and tissues of the human organism. It originates from a stromal fibroblastic cell positive to CD4. We undertook this study to determine the clinical and histopathological characteristics of SFT found from January 1, 2002-January 31, 2010 in a concentrated third-level general hospital in Mexico City. Methods: We present 16 resected cases of different localizations: three pleural, three mediastinal, three lung, two oral cavity, one nasopharyngeal, one in the lateral aspect of the neck, one kidney, one paratesticular and another in the crural region. All were studied with hematoxylin and immunoperoxidase. Results: There was similar affection in both genders. Mean age was 51 years (range: 43-81 years). Two pleural cases presented recurrence and one had hypoglycemia but none demonstrated metastases. No deaths were registered during a mean follow-up of 18 months. Histological pattern corresponded to a fusocellular growth that coincided with hemangiopericytoid zones in five cases and sarcomatoid in four. These cases were considered as mixed. All were positive to vimentin. Conclusions: Definitive diagnosis must be made by immunoperoxidase. Immediate treatment is surgical resection; relapses are rare. There were two pleural cases with recurrence.