A Pulmonary Lesion Which Is More Than Meets the Eye

Abstract

A 69-year-old female smoker presented with dyspnea, anorexia, weight loss, and bone pain. Chest radiography showed a large pulmonary mass. Initial clinical investigations suggested probable metastatic bronchogenic carcinoma, but biopsy revealed that the lesion represented primary pulmonary lymphoma. The pathogenesis of primary pulmonary parenchymal lymphoma is discussed, and differential diagnosis of this entity is reviewed.A 69-year-old woman presented with a 3 month history of increasing dyspnea, anorexia, and weight loss of 4 kg. She also complained of lower back and right-sided chest wall pain at presentation. The past medical history was remarkable for chronic obstructive pulmonary disease and a 40 pack a year history of smoking.Mild bilateral wheezing was noted on physical examination, but evidence of digital clubbing, lymphadenopathy, or focal bone tenderness was not noted. Chest radiography showed a 4-ϫ-6-cm left lower lobe mass ( Fig. 1). Laboratory investigations were remarkable only for an elevated erythrocyte sedimentation rate of 39 mm/hour (normal Ͻ12 mm/ hour).Thoracic computed tomography (CT; Fig. 2) demonstrated emphysema and a left anterior-medial basal segment mass, but no evidence of lymphadenopathy or other pulmonary abnormalities was found. No adrenal lesions were noted. Radionuclide bone scanning showed focal tracer accumulation within the T9 thoracic vertebral body and within 2 right lower posterior ribs. Bronchogenic carcinoma, possibly metastatic, was the presumptive diagnosis.Flexible fiberoptic bronchoscopy was performed and showed an endobronchial lesion within the left anterior basal region. Endobronchial biopsies and bronchoalveolar washings were performed and sent for histopathological assessment.Histopathological assessment of the material obtained at bronchoscopy showed sheets of large, pleomorphic, malignant appearing lymphoid cells (Fig. 3). Epithelial markers CAM 5.2 and AE1/AE3 for carcinoma were negative. These findings were consistent with high grade, large B-cell lymphoma.CT scanning of the abdomen and the pelvis performed for staging revealed no significant abnormalities. Bone marrow aspirate and biopsy showed normal cellularity. Hematological investigations were normal. Dedicated radiographs of the right lower ribs and the thoracic spine showed that the areas of tracer accumulation on the bone scan represented degenerative changes. Based on CT findings, analysis of the histopathological specimens, and the bone marrow aspirate, a diagnosis of stage II E non-Hodgkin primary pulmonary lymphoma was made. The patient underwent standard CHOP regimen chemotherapy; cyclophosphamide 750 mg/m 2 IV on day 1, doxorubicin 50 mg/m 2 IV on day 1, vincristine 1.4 mg/m 2 IV capped at 2 mg on day 1, and prednisolone 100 mg PO qd on days 1 through 5. This regimen was repeated every 21 days for 4 cycles.