Search

Two cases with the co-existence of micronodular thymoma and lymphoma are presented. The patients are two female patients 54 and 60 years of age who presented with symptoms of chest pain, general malaise, cough, and dyspnea. Diagnostic imaging demonstrated the presence of an anterior mediastinal mass. Initial biopsy was interpreted as an epithelial neoplasm compatible with thymoma. Surgical resection took place demonstrating the presence of micronodular thymoma in both cases. In addition, in both cases the lymphoid proliferation infiltrated surrounding adipose tissue. However, in one case the lymphoid proliferation was composed of atypical lymphocytes with irregular nuclei and increase mitotic activity positive for CD3 and TDT, while in the second case, the lymphoid proliferation was composed of more mature lymphocytes with a monocytoid appearance and positive for CD20. Both of these cases represent an unusual association and one that must be kept in the differential diagnosis especially in cases of micronodular thymoma.

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.

Three cases of primary pulmonary adenocarcinoma with prominent lymphoid stroma and papillary features mimicking Warthin's tumor are presented. The patients are two women and one man ages 52, 62, and 74 years respectively. Clinically, the patients presented with non-specific symptoms of cough, dyspnea, and chest pain. Imaging showed the presence of an intrapulmonary mass in the right lower, right upper and left lower lobe. All patients underwent lobectomy. Histologically, the tumors were characterized by the presence of and oncocytic papillary growth pattern embedded in a lymphoid rich background. Immunohistochemical stains for TTF-1, keratin 7, and beta-catenin were positive in the epithelial component, while CD20 showed strong positive staining in the lymphoid component. In addition, CD4 and CD8 also showed positive staining in a ratio of 3-4:1, EBER was negative. Kras mutations with wild type EGFR were identified in one case. Clinical follow-up ranging from 8 to 24 months was obtained showing that all patients are alive without recurrence. The cases herein presented represent an unusual histological variant of primary lung adenocarcinoma, which closely mimics Warthin's tumor.

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.