The silent giant: A rare case of a pleural hemangiopericytoma.
Gorgis S, Sen P, and Jennings J. The silent giant: A rare case of a pleural hemangiopericytoma. Am J Respir Crit Care Med 2017; 195.
Am J Respir Crit Care Med
Primary pleural neoplasms are a rare cause of intrathoracic masses, which typically represent mesotheliomas or fibrous tumors. The introduction of lung cancer screening through imaging has resulted in increased detection and biopsies of pleural growths in asymptomatic patients. We present a case of slowly growing solitary fibrous tumor (hemangiopericytoma) in an asymptomatic patient. CASE PRESENTATION An 84 year old gentleman was referred to the Pulmonology clinic for evaluation of a lung mass. In 2011 a screening CT thorax revealed a 4x5cm right lower lobe pleural based mass that was not further worked up given no symptoms. Follow up imaging in 2016 revealed significant mass enlargement (17x18cm) with mass effect on the right lung, hilum, and mediastinum. There was internal vascularity, but no invasion of the chest wall or mediastinal structures. The patient lost 15lb in one year, but denied any shortness of breath, chest pain, night sweats, cough, stridor, wheezing, or any lumps/bumps. He smoked for a few years, but quit over 40 years ago. He worked in an automobile factory, but denied known exposure to radiation, asbestos, or other toxins. Physical examination revealed diffusely reduced breath sounds over the right lung. His LDH and CEA were normal. CT-guided core biopsy revealed CD34 positive, cytokeratin negative, very weak desmin expression consistent with a solitary fibrous tumor. He declined surgical resection given lack of symptoms. DISCUSSION Solitary fibrous tumors (SFTs) are mesenchymal neoplasms of fibroblastic origin that account for less than two percent of all soft tissue tumors. They occur between the fifth and seventh decade of life with no known associated environmental exposure to radiation, tobacco, or asbestos. SFTs were first described in 1931 as primary tumors of the pleura, but required decades of histopathological investigation before being considered an entity that is cytogenetically identical to hemangiopericytomas. They are usually less than 10cm in size, but can grow up to 40cm. As intrathoracic tumors they have been reported to cause pleural effusions, diaphragmatic elevation, mass effect, and vascular invasion which cause shortness of breath, cough, dysphagia, pleuritic chest pain, clubbing, or restricted joint movement. Rarely, large masses can cause secretion of insulin-like growth factor-2 resulting in hypoglycemia, a syndrome referred to as Doege-Potter syndrome. Our case demonstrates the significance of interval follow up of solitary fibrous tumors since the sheer size can lead to significant clinical complications. Surgical resection is the gold standard for treatment. (Figure presented).