Search

Two cases of primary follicular dendritic cell sarcoma (FDCS) of the pleura are presented. The patients are a woman 76-years-old and a man 64-years-old who presented with nonspecific symptoms including chest pain, dyspnea, and cough. Clinical history did not disclose any pertinent history of previous malignancy. Diagnostic imaging showed the presence of a pleural-based mass in both patients and a thoracotomy with resection of the pleural mass was performed. Both tumors were described as solid, light tan, and with ill-defined borders. Histologically, both tumors showed similar histological features, namely the presence of a spindle cellular proliferation composed of elongated cells with fibrillary cytoplasm, oval nuclei, and conspicuous nucleoli. Mild to moderate cellular atypia was present, while mitotic figures ranged from 3 to 4 per 10 high power fields. Mature lymphocytes and plasma cells were also present dispersed throughout the tumor. Immunohistochemical stains in both cases show positive staining for CD21 and CD35 while focal staining was present for D2-40 and clusterin, while negative for other markers including keratin, desmin, S-100 protein, calretinin, and STAT-6. Clinical follow up shows that both patients have remained alive 12 and 14 months after initial diagnosis. The cases herein described represent an unusual occurrence of FDCS arising in the pleural surface and one that must be kept in mind when dealing with spindle cell tumors of the pleura.

Two cases of primary intrapulmonary hyalinizing spindle cell tumor with giant rosettes are presented. The patients are one woman and one man ages 37 and 42 years respectively. Both patients presented with non-specific symptoms of cough, dyspnea, and chest pain. Imaging revealed the presence of an intrapulmonary mass. One tumor was located in the left lower lobe while the other tumor was in the right upper lobe. Both patients underwent lobectomy. The tumors ranged from 2.4 to 3.0 cm in greatest dimension and were characterized by the presence of a bland spindle cell proliferation with areas of hyalinization and the presence of the so-called giant rosettes. Immunohistochemical stains were performed and the spindle cell component show positive staining for vimentin and negative staining for Bcl-2, CD34, STAT6, p40. Keratin immunohistochemical stain highlighted the entrapped alveolar epithelium while S-100 protein showed weak focal staining in the spindle cells. Both patients have remained alive and well without evidence of recurrence or metastasis for a period of 6 to 14 months post-surgical resection. The cases herein presented highlight the ubiquitous distribution of this tumor and underscores the importance of keeping this particular tumor in the differential diagnosis of spindle cell tumors of the lung.