Primary thymic marginal zone B-cell lymphoma (MZBL) of mucosa-associated lymphoid tissue (MALT)-type is a very rare disease with distinct clinicopathologic features. I herein report a rare case of primary thymic MZBL of MALT-type arising in the thymus in a patient with Sjogren's syndrome and rheumatoid arthritis. A mediastinal mass was detected by computerized tomography in a 43-yr-old Korean woman with a history of Sjogren's syndrome and rheumatoid arthritis and the thymus was resected through median sternotomy. The solid and nodular tumor (7x6x3cm) was confined in the thymus. Histologically, the lymphoid infiltrate comprised monotonous centrocyte-like cells with monocytoid cells, small lymphocytes, and plasma cells. Prominent lymphoepithelial lesions were formed by centrocyte-like cells infiltrating the Hassall's corpuscles. Immunohistochemically, the tumor cells were positive for CD20, CD79a, and bcl-2 and negative for CD3, CD5, CD10, CD23, and bcl-6. IgA and kappa light chain restriction were also found in plasma cells in the tumor. Sjogren's syndrome and rheumatoid arthritis are known to be associated with MALT lymphoma and were considered to play an important role in the development of malignant lymphoma in this patient.
Adult ; Arthritis, Rheumatoid/*complications/immunology ; B-Lymphocytes/metabolism ; Female ; Human ; Lymphoma, Mucosa-Associated Lymphoid Tissue/diagnosis/*etiology/immunology ; Sjogren's Syndrome/*complications/immunology ; Thymus Neoplasms/immunology/*pathology ; Tumor Markers, Biological

Although renal calcium crystal deposits (nephrocalcinosis) may occur in acute phosphate poisoning as well as type 1 renal tubular acidosis (RTA), hyperphosphatemic hypocalcemia is common in the former while normocalcemic hypokalemia is typical in the latter. Here, as a unique coexistence of these two seperated clinical entities, we report a 30-yr-old woman presenting with carpal spasm related to hypocalcemia (ionized calcium of 1.90 mM/L) due to acute phosphate poisoning after oral sodium phosphate bowel preparation, which resolved rapidly after calcium gluconate intravenously. Subsequently, type 1 RTA due to Sjogren's syndrome was unveiled by sustained hypokalemia (3.3 to 3.4 mEq/L), persistent alkaline urine pH (> 6.0) despite metabolic acidosis, and medullary nephrocalcinosis. Through this case report, the differential points of nephrocalcinosis and electrolyte imbalances between them are discussed, and focused more on diagnostic tests and managements of type 1 RTA.
Acidosis, Renal Tubular/*diagnosis/etiology ; Acute Disease ; Adult ; Antibodies, Antinuclear/blood ; Calcium Gluconate/therapeutic use ; Chronic Disease ; Female ; Humans ; Hydrogen-Ion Concentration ; Hypocalcemia/*chemically induced/complications/drug therapy ; Nephrocalcinosis/complications/*diagnosis/ultrasonography ; Parotid Gland/ultrasonography ; Phosphates/*adverse effects ; Salivary Glands/radionuclide imaging ; Sjogren's Syndrome/complications/*diagnosis/metabolism ; Submandibular Gland/ultrasonography