The gastrointestinal (GI) tract is the most frequently involved site of mucosa-associated lymphoid tissue (MALT) lymphoma. Stomach is the most common site of involvement among the GI tract. However, MALT lymphoma of the large intestine is rare. A diagnosis is established by pathological examination of the surgical or endoscopic specimens. A 72-year-old man with low abdominal pain was diagnosed as a sigmoid MALT lymphoma, which was noted as an obstructing mass in a colonoscopic examination. A left hemicolectomy was performed, and the patient has had no recurrence postoperatively without any chemotherapy.
Aged ; Colon, Sigmoid/*pathology ; Colonoscopy ; Diagnosis, Differential ; Humans ; Lymphoma, B-Cell, Marginal Zone/*diagnosis/pathology/radiography ; Male

<b>OBJECTIVEb>To investigate the clinical and computed tomography (CT) appearances of pulmonary mucosa-associated lymphoid tissue (MALT) lymphoma.

<b>METHODSb>The CT findings and clinical data of 13 patients with pathologically proven pulmonary MALT lymphoma were retrospectively reviewed.

<b>RESULTSb>Among these 13 patients, seven presented no notable abnormalities, six manifested respiratory symptoms including cough, expectoration, and dyspnea; one of these six patients experienced fever. Chest CT showed solitary nodule in 2 patients and multiple nodules in 3 patients; meanwhile, it showed solitary consolidation in 3 patients and multiple consolidations in 5 patients. Other CT findings included air bronchogram (n = 13), airway dilatation (n = 4), ground glass opacities (n = 5), and interstitial changes (n = 5). One patient had mediastinal lymphoadenopathy and 2 had pleural effusion. Pathology showed massive lymphocyte infiltration; cells with notable nuclear atypia were also seen, which were generated from B cells.

<b>CONCLUSIONSb>The main CT findings of pulmonary MALT lymphoma include nodules, mass or patchy consolidations with air brochogram; hilar and mediastinal lymphadenopathies are rare. Clinical diagnosis should also be based on pathological findings and immunohistochemical results.

Adult ; Aged ; Female ; Humans ; Lung Neoplasms ; diagnosis ; diagnostic imaging ; pathology ; Lymphoma, B-Cell, Marginal Zone ; diagnosis ; diagnostic imaging ; pathology ; Male ; Middle Aged ; Radiography ; Retrospective Studies