Management of Primary Plasma Cell Leukemia Remains Challenging Even in the Era of Novel Agents.

Primary plasma cell leukemia (PCL) is a rare and aggressive variant of multiple myeloma (MM). PCL is characterized by peripheral blood involvement by malignant plasma cells and an aggressive clinical course leading to poor survival. There is considerable overlap between MM and PCL with respect to clinical, immunophenotypic, and cytogenetic features, but circulating plasma cell count exceeding 20% of peripheral blood leukocytes or an absolute plasma cell count of >2000/mm distinguishes it from MM.

Liver failure due to relapsed myeloma and hepatic iron overload.

Multiple myeloma is a hematologic malignancy that classically manifests with hypercalcaemia, renal insufficiency, anaemia and lytic bone lesions. Liver dysfunction in multiple myeloma is a lesser known complication that occurs through biliary obstruction, liver infiltration by plasma cells, amyloid/light chain deposition or due to liver injury from medications. Although transfusion-related hepatic iron overload-leading to significant liver disease-is a recognised complication in certain hematologic malignancies, little is known about transfusional iron overload in patients with multiple myeloma.

Biphasic Malignant Pleural Mesothelioma Masquerading as a Primary Skeletal Tumor.

Biphasic malignant pleural mesothelioma is a rare malignant tumor, usually presenting as a pleural-based mass in a patient with history of chronic asbestos exposure. We herein report a case of a 41-year-old man who presented with chest pain and had a chest computed tomography (CT) scan suggestive of a primary skeletal tumor originating from the ribs (chondrosarcoma or osteosarcoma), with no history of asbestos exposure. CT-guided core needle biopsies were diagnosed as malignant sarcomatoid mesothelioma.

Pneumocystis Pneumonia Presenting as an Enlarging Solitary Pulmonary Nodule.

Pneumocystis pneumonia is a life threatening infection that usually presents with diffuse bilateral ground-glass infiltrates in immunocompromised patients. We report a case of a single nodular granulomatous Pneumocystis pneumonia in a male with diffuse large B-cell lymphoma after R-CHOP therapy. He presented with symptoms of productive cough, dyspnea, and right-sided pleuritic chest pain that failed to resolve despite treatment with multiple antibiotics.

Combined Intrathoracic and Subcutaneous Splenosis Discovered 51 Years after Abdominal Trauma.

Splenosis is a rare condition that results from the autotransplantation of splenic parenchyma into unexpected locations such as the abdomen or subcutaneous tissue. In the presence of coexisting injury to the diaphragm intrathoracic transplantation can occur emerging as single or multiple pleural-based masses. This occurs after traumatic rupture of the spleen and is usually asymptomatic, only to be discovered incidentally on routine thoracic or abdominal imaging.

Bronchial carcinosarcoma.

Carcinosarcoma is an uncommon mixed tumor of the lung. We present the case of a 65 year-old-male with cough and a right lower lobe radio-opacity who underwent resection, showing a large endobronchial tumor with an epithelial component of non-small cell carcinoma and malignant mesenchymal elements. The radiologic and histopathologic features are reviewed with reference to relevant literature.

Palmitoylation controls trafficking of GAD65 from Golgi membranes to axon-specific endosomes and a Rab5a-dependent pathway to presynaptic clusters.

The GABA-synthesizing enzyme GAD65 is synthesized as a soluble cytosolic protein but undergoes post-translational modification(s) to become anchored to the cytosolic face of Golgi membranes before targeting to synaptic vesicle membranes in neuroendocrine cells. Palmitoylation of cysteines 30 and 45 in GAD65 is not required for targeting to Golgi membranes but is crucial for post-Golgi trafficking to presynaptic clusters in neurons. Here, we show that palmitoylated GAD65 colocalizes with the small GTP-binding protein Rab5a in Golgi membranes and in axons but not in dendrites.