A previously healthy 19-year-old female of Asian ethnic origin, visited our hospital for an evaluation of abnormal chest CT findings on routine physical examination. On admission the patient was asymptomatic, without fever, cough, lymphadenopathy, night sweats or weight loss. As shown in , the patient had normal complete blood count. Additional tests revealed minimally elevated erythrocyte sedimentation rate. The antinuclear antibody test was negative. The levels of lactate dehydrogenase, β2 microglobulin and liver function tests were normal. The tests for tuberculosis, human immunodeficiency virus and other viruses, including hepatitis A, B and C, were all negative. The spleen and liver were of normal size and echogenicity. Spiral lung CT revealed bilateral multiple pulmonary consolidations, with the largest lesion sized ~4.5×4.5 cm (). Bone marrow aspiration was negative for lymphoma involvement. The patient underwent CT image-guided biopsy and the diagnosis of pMALToma was confirmed. The microscopic examination revealed lymphoepithelial lesions characterized by diffuse infiltration of the lung parenchyma by small lymphocytes, monocytoid cells and plasma cells (). Immunohistochemical staining demonstrated that the cells were positive for CD20 and B-cell lymphoma 2 protein, with 10% nuclear staining for Ki-67. According to the pathological findings, the patient was treated with 6 courses of chemotherapy with 2 mg vincristine, 4 mg/day chlorambucil plus 30 mg/day prednisolone for 7 days. After 2 cycles of chemotherapy, all the pulmonary lesions were significantly reduced in size (). Complete remission of the lung consolidations was observed following 6 cycles of treatment, as visualized by CT scan (). Fifteen months after the last course of chemotherapy, the patient was in good condition without any evidence of relapse. The patient remains in follow-up.
A 35-year-old woman was found to have a few shadows with GGOs on chest CT in 2012. She was monitored and a shadow in right S10 was found to increase in size, which suggested lung adenocarcinoma. The patient was referred to our hospital for further evaluation. The patient had a history of bronchial asthma. The shadow in right S10 had increased to 14 × 8 mm by 2015 (Fig. ). Other shadows also appeared (Fig. ). After preoperative CT-guided marking, the patient underwent video-assisted thoracoscopic surgery with a right wedge resection of the lower lobe that included the largest nodule in S10 and other nodules. Her postoperative course was uneventful.\nGrossly, the surgical specimen contained pale, somewhat yellow lesions (Fig. ). Histopathological examination of the right S10 lesion and other nodules revealed small- or medium-sized lymphocyte-like cells that were located in the alveolar interseptal spaces. The alveolar walls remained intact (Fig. , ). Immunohistochemical staining showed that tumor cells were positive for CD20 (1:400 dilution; DAKO, Carpinteria, CA, USA, Fig. ), CD79a (1:200 dilution; DAKO, Carpinteria, CA, USA), and BCL2 (1:50 dilution; DAKO, Carpinteria, CA, USA, Fig. ) expression and negative for CD10 (1:50 dilution; Novocastra, Newcastle upon Tyne, UK), cyclin D1 (1:75 dilution; DAKO, Carpinteria, CA, USA) and CD30 (1:40 dilution; DAKO, Carpinteria, CA, USA). The lesions were diagnosed as extranodal marginal zone B-cell lymphoma of MALT. The patient has remained well during 12 months of follow up after surgery. Although she did not receive chemotherapy because the MALT lymphoma lesions have been stable without progression, the patient is kept under close observation because of potential progression of the disease.