We describe a patient with intravascular pulmonary lymphoma who presented with progressive dyspnea and hypoxemia with normal chest radiographic findings. After an unrevealing noninvasive evaluation, a high-grade B-cell intravascular lymphoma was diagnosed by bronchoscopy with transbronchial biopsy. Treatment with a modified CHOP regimen resulted in resolution of the patient's hypoxemia and exercise limitation. Although intravascular pulmonary lymphoma rarely presents with pulmonary symptoms, it should be considered in the differential diagnosis of patients presenting with hypoxemia and normal chest radiographic findings.
The case
A 55-year-old female nonsmoker presented with a chief complaint of 6 weeks of progressive severe exertional dyspnea. She denied chest pain, cough, sputum production, hemoptysis, rash, arthralgias, fever, night sweats, and chills. Two weeks before presentation, the patient noted fatigue and weakness, with occasional diarrhea but no melena or hematochezia. Twenty years previously, she had been treated for tuberculosis with a 6-month 4-drug regimen.
The patient's physical examination findings were unremarkable. Her heart rate and respiration rate were normal at rest. Pulse oximetry showed an oxygen saturation of 88% on room air, and arterial blood gas analysis revealed a PaO2 of 58 mm Hg. Her oxygen saturation rose to 95% on 2 L of oxygen via nasal cannulae.
Chest radiographic and ECG findings were normal. The results of a ventilation-perfusion scan were interpreted as very low probability for pulmonary embolism, and spirometry demonstrated a mild obstructive defect. A high-resolution CT pulmonary angiogram showed minimal left apical scarring consistent with well-healed tuberculosis.
The results of routine laboratory tests, including liver function tests, were normal, except for a lactate dehydrogenase (LDH) level of 1409 U/L (normal, 185 to 290 U/L). Over the course of a few days, generalized edema developed. The patient's aspartate aminotransferase level increased to 115 U/L (normal, 10 to 47 U/L), and her albumin level decreased to 2.6 g/dL (normal, 3.6 to 4.8 g/dL). The results of a hepatitis profile and urinalysis were normal. An echocardiogram demonstrated normal ventricular function and chamber sizes with a patent foramen ovale, although a significant right-to-left shunt was not demonstrated.
