Mesenchymal cells in areolar tissue next to the pleura encourage the growth of solitary fibrous pleural tumors.
8 More than half of all patients with such tumors are asymptomatic, and 80% of such masses are benign.
2 Extrinsic compression of the solitary fibrous pleural tumor on lung parenchyma may cause patients to seek medical care with the common symptoms of cough, dyspnea, and chest pain. These complaints, along with hypertrophic pulmonary osteoarthropathy, are found in more than 33% of symptomatic patients.
8 An alternate patient presentation may be tumor-associated hypoglycemia, which is caused when the tumor produces insulin-like growth factors. This particular symptomology is seen in the paraneo-plastic phenomenon referred to as Doege-Potter syndrome.
9
Eighty percent of solitary fibrous pleural tumors are of visceral origin. The other 20% originate in the parietal pleura.
8 Only one case of a solitary fibrous pleural tumor reported in the medical literature has suggested a genetic component.
10 However, it is possible that this familial case may have resulted from exposure to a common environmental agent or a germline mutation that was genetically transmitted.
10
Histologic evaluation usually discloses cellular areas with intermittent hyalinized or necrotic areas, while electron microscopy reveals both fibroblasts and mesothelial cells.
8 Findings from CT scans depend largely on the location, size, and histologic features of the tumor. However, such lesions typically are well defined with clear margins and smooth contours. In addition, they usually have homogenous attenuation and are at right or obtuse angles with the pleura. Larger lesions have been noted to have more lobulated contours and “geographic” patterns. Larger lesions are also most often at acute angles with the pleura.
11
The size of the tumors can vary greatly—between 1 cm and 36 cm (mean, 6 cm) in diameter.
8 Many large tumors are pedunculated on pleural-based pedicles with hypertrophic vasculature.
8 Numerous thin-walled vessels may be present in larger tumors.
8 Although no single histologic feature provides a definitive prognosis, the presence of a pedicle supporting a well-circumscribed tumor without invading the surrounding structures of the lung, mediastinum, or chest wall is an indicator of a good prognosis.
8
One review of the literature
2 concluded that complete surgical resection was the preferred therapy for both benign and malignant solitary fibrous pleural tumors. It also stated that though pedunculated tumors are effectively removed using wedge resection, sessile lesions require that a larger mass of lung parenchyma be excised to reduce the likelihood of local tumor recurrence.
2 However, local recurrence is not as worrisome in benign lesions, which have an 8% chance of recurrence, compared with malignant lesions, which have a 63% recurrence rate even after complete resection.
2 Although the majority of recurrent tumors are fatal within 2 years, recovery rate is estimated at 88% to 92% for all patients with solitary fibrous pleural tumors.
2
In a prospective study,
12 18 patients were treated with complete resection of tumors with a mean size of 10 cm, receiving follow-up at approximately 61 months. Histologic features were benign in 16 patients and malignant in the remaining 2. The authors determined that the recovery rates were 100% at 1 year, 93% at 3 years, and 80% at 5 years. Tumor recurrence was associated with malignant histology, parietal pleura origin, and a lower expression of progesterone receptors.
12 One disquieting case documented the recurrence of a solitary fibrous pleural tumor four times within 10 years, ending finally with a malignant transformation.
13
Biopsy before excision, however, is controversial. Scarsbrook and colleagues
14 recounted an alarming case in which a solitary fibrous pleural tumor recurred after an ultrasound-guided transthoracic biopsy. Although there have been no other similar reports in the literature, it seems prudent to avoid unnecessary biopsy to prevent this potential complication. As the study
14 recommends, biopsy should only be done if disease management will be substantially affected by the results or if surgical intervention is contraindicated and a diagnosis would alter treatment.