Concurrent thymoma and lymphoma: a report of two cases

Combined Thymic Epithelial Neoplasms - a Review

Thymic epithelial neoplasms are the most common tumors of thymic origin but are overall rare in the general population. Their morphologic diversity, ranging from low grade to overtly malignant lesions, along with various histologic growth patterns make them a diagnostically challenging group of tumors. Very occasionally, thymomas and thymic carcinomas may develop in combination with other benign or malignant lesions of thymic origin, further complicating the diagnostic process. The focus of this review lies on the spectrum of thymic epithelial tumors that present with other thymic lesions in the same tumor mass, such as multilocular thymic cysts, neuroendocrine neoplasms, lymphomas, and germ cell tumors among others. Awareness of the existence of such unusual tumors may not only aid in their diagnosis but may also have implications for prognostic and therapeutic purposes.

Distinguishing thymoma from T-lymphoblastic leukaemia/lymphoma: a case-based evaluation

T-lymphoblastic lymphoma and thymoma are distinct primary mediastinal neoplasms that can have similar clinical presentations and overlapping histological features. Microscopic distinction is occasionally difficult because the immature lymphocytes associated with thymoma may resemble T-lymphoblastic leukaemia/lymphoma cells, morphologically and immunohistochemically. An accurate diagnosis assumes particular importance since the treatment approaches for these two entities differ considerably. Multimodality diagnostic approaches incorporating histological, flow cytometry immunophenotypic' and molecular approaches are required. In this article, we describe four patients, each presenting with a mediastinal tumour in different clinicopathological settings. A detailed report of each case will follow, illustrating the challenges involved in the diagnosis in patients with these mediastinal neoplasms.

Thymoma and multiple malignancies: a case of five synchronous neoplasms and literature review

The presence of five discrete synchronous or metachronous primary neoplasms in a single patient is an extremely rare event. This is a report of a patient with a malignant (invasive) thymoma and four other independent primary neoplasms including: gliosarcoma, papillary thyroid cancer, meningioma and metastatic adenocarcinoma of the colon, found synchronously at autopsy. Thymoma patients appear to have an inherent predisposition towards developing additional neoplasms. Other than the thymoma, the presented patient had no obvious risk factors for neoplasia. This case provides evidence for an unusual syndrome of thymoma and multiple primary neoplasms. Further research is required to elucidate the mechanism of this association. Meanwhile, heightened awareness of this association may allow earlier detection and treatment of additional cancers in patients with a history of thymoma.

Composite thymoma and chronic lymphocytic leukemia/small lymphocytic lymphoma involving the anterior mediastinum

Simultaneous involvement of the anterior mediastinum by thymoma and B-cell chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL), to our knowledge, has not been previously reported. We describe a composite tumor composed of thymoma and CLL/SLL incidentally discovered in a 62-year-old man who had no history of malignant diseases or immunologic disorders. The preoperative peripheral blood specimen showed a normal complete blood cell count and differential count. The diagnosis was established by histologic examination and immunophenotypic studies of the surgically excised anterior mediastinal mass. Postoperatively, bone marrow aspiration and biopsy specimens showed morphologic evidence of CLL/SLL, and the presence of neoplastic cells in peripheral blood and bone marrow was confirmed by flow cytometry immunophenotypic analysis.

Thymic malignancies

Thymomas and thymic carcinomas are unique tumors of the anterior mediastinum. The association of a variety of different paraneoplastic syndromes with such lesions has fascinated physicians and researchers for years. Most recently, it has been demonstrated by numerous authors that thymomas are chemosensitive tumors. Their indolent nature and relative rarity have made evaluation through prospective randomized clinical trials extremely difficult. Further information regarding the molecular nature of these neoplasms and immunologic aspects is needed in future investigation.

Unusual presentation of mycosis fungoides as pigmented purpura with malignant thymoma

Thymoma is known to be associated with many lymphoreticular and nonlymphoreticular tumors. A woman who presented with patch stage mycosis fungoides with skin lesions resembling a pigmented purpura was found to have an anterior mediastinal mass on routine staging evaluation. A core needle biopsy of the mass revealed a lymphocyte predominant malignant thymoma. Review of the literature reveals many diseases with dermatologic manifestations associated with thymoma; however, malignant thymoma coexisting with mycosis fungoides has not previously been reported.