%0 Journal Article %T Systemic Lymphadenopathy as the Initial Presentation of Malignant Mesothelioma: A Report of Three Cases %A Yaxia Zhang %A Zohreh M. Taheri %A Merce Jorda %J Pathology Research International %D 2010 %I Hindawi Publishing Corporation %R 10.4061/2010/846571 %X Systemic lymph node metastasis is a rare event in malignant mesothelioma. It is even more exceptional when systemic lymph node metastasis is the initial clinical presentation. Review of literature discloses only four cases in which metastatic lymphadenopathy was the only symptom of malignant mesothelioma. We, herewith, report three cases where the initial diagnosis of malignant mesothelioma was made by biopsy of enlarged lymph nodes, which were the only clinical presentation. Immunohistochemistry played a pivotal role in elucidating the mesothelial origin of their unusual systemic lymph node metastasis. 1. Introduction Malignant mesothelioma (MM) is an uncommon neoplasm which is characterized by highly aggressive behavior and poor prognosis [1]. The neoplasm predominantly involves pleural and peritoneal cavities, with a smaller percentage of cases arising in the pericardial sac and testicular tunica vaginalis [2]. Clinically, the majority of patients have local symptoms such as chest or abdominal pain and dyspnea, depending on the site of origin. Occasionally, patients may present with distant metastasis. Systemic lymphadenopathy, however, is an exceeding rare initial presentation of this disease [3]; thirteen cases have been reported in literature. In four of those, systemic lymphadenopathy was the only clinical manifestation [4¨C6]. In this report, we describe three additional cases of primary peritoneal MM in which the initial diagnosis of the disease was made by biopsy of neck, supraclavicular lymph nodes, and axillary lymph nodes. Two cases were primary from peritoneum and the third originated in the pleura. 2. Report of Cases 2.1. Case One A 50-year-old male with no past medical history presented with progressive enlargement of lymph nodes in his left groin and right inferior neck over a period of 6 months. PET scan showed high uptake in several areas such as mediastinum, pericardial region, cardiophrenic angles, supraclavicular area, internal mammary, perihepatic region, and groin with standardized uptake values (SUVs) ranging from 4.8 to 12.5. Most of these uptakes were interpreted as presence of a malignant process probably malignant lymphoma. Immediate assessment on fine needle aspiration cytology from left groin lymph node, however, ruled out the diagnosis of malignant lymphoma. A subsequent core biopsy was obtained from right supraclavicular node and was interpreted as metastatic malignant epithelial neoplasm to lymph node. The neoplasm was characterized by a diffuse growth of polygonal cells with well-defined cell membranes and dense %U http://www.hindawi.com/journals/pri/2010/846571/