Primary spindle cell tumors (PSCT) in the thorax are rare neoplasms, typically presenting with mild or non-specific symptoms. We report an unusual case of PSCT of the pleura presenting with a large, symptomatic pleural effusion.
A 55-year-old Chinese woman presented with dyspnea and right chest discomfort for two months. Chest radiography and CT scanning confirmed a large, multi-loculated right pleural effusion with a network of multiple enhancing septations (Fig 1). Pleurocentesis gave no positive microbiological or cytological result, but exploration by video-assisted thoracic surgery (VATS) confirmed a poorly differentiated PSCT of the pleura. A thick peel of tumor and exudate involving the entire parietal pleura and encasing the right lung made curative surgery technically impossible, but palliative drainage and debulking gave good postoperative symptomatic relief. Six months later, the patient presented again with severe dyspnea and superior vena cava obstruction. Chest radiography revealed a white-out of the right hemithorax with marked mediastinal shift (Fig 2A). CT scan confirmed a huge heterogeneous mass with both cystic and solid components occupying the entire right hemithorax and extending into the right chest wall (Fig 2B). The trachea was compressed to a transverse diameter of 3mm at the level of the aortic arch. The severe cardiopulmonary compromise rendered the risk for general anesthesia prohibitively high. The patient was managed non-surgically, with palliative ultrasound-guided pleurocentesis giving partial relief of her dyspnea. The patient died four weeks after this second presentation.
PSCT’s of the lung and pleura are rare primary thoracic sarcomas (PTS), which in turn constitute less than 1% of all thoracic malignancies[1,2]. A diagnosis of PSCT is usually one of exclusion, reserved for primitive, poorly differentiated sarcomas possessing spindle cell elements but lacking other histologically distinguishing features. Diagnosis is made on histological and immunohistochemical analysis of a tissue biopsy. The differential diagnosis for a thoracic soft tissue tumor containing spindle cell elements includes sarcomatoid carcinoma, leiomyosarcoma, synovial sarcoma, fibrosarcoma, epithelioid sarcoma, solitary fibrous tumor, hamartoma, and others. For sarcomatous tumors diffusely involving the pleura, the differential diagnosis would further include malignant mesothelioma, pseudomesotheliomatous metastatic adenocarcinoma, thymoma, and fibrous tumor of the pleura. Patients with PTS are often asymptomatic, or have only mild, non-specific presentations, such as cough, chest pain, and dyspnea[1,2]. Radiologically, these sarcomas are well-circumscribed, but have no distinguishing features. Presentation of PTS with pleural manifestations is remarkably rare. There are infrequent reports of pleural effusion caused by sarcomas metastasizing to the pleura from an extra-thoracic primary. In one of the rare case series of primary smooth muscle tumors of the pleura, one of the five cases reported developed a pleural ‘empyema’. However, to our knowledge, ours is the first reported case of a PSCT of the pleura presenting chiefly with a symptomatic pleural effusion. Most thoracic PSCT’s are high grade malignancies with aggressive biological behavior. Managed conservatively, patients with PTS typically die within two years. With complete surgical resection, the 5-year survival rate reportedly improves to 43–69%. The role of adjuvant or neo-adjuvant chemotherapy is thus far unproven. Hence, surgery remains the treatment of choice. Failure of complete curative resection, as in this case, is an indicator of poor prognosis.
A large, symptomatic pleural effusion may represent a rare mode of presentation for PSCT of the pleura. In this case, the effusion was associated with advanced, unresectable disease.
A.D. Sihoe, None.