Introduction: Intravascular lymphomatosis (IVL) is a rare lymphoma that is usually of B-cell origin with a particular predilection for the lumen of small blood vessels. The malignant cells usually proliferate within the vasculature and eventually compromise blood flow leading to clinical symptoms. In the case reports and case series to date, the skin and nervous system are the two most commonly involved organs.1 Rarely, the lung is the predominate organ involved and the diagnosis is difficult to make antemortem. This report describes the first case, to our knowledge, of IVL that presented with evidence of airflow obstruction and air trapping on pulmonary function testing and a mosaic perfusion pattern on high-resolution CT (HRCT) of the chest. Case Presentation: A 63-year-old man who had quit smoking 30 years previously, presented with a 3 month history of progressive dyspnea on exertion, one month history of a dry, nonproductive cough, intermittent fevers as high as 103.7°F, night sweats, and weight loss. Dyspnea was present after ambulating only 100 yards. There was no prior history of lung disease or occupational dust exposure. Physical examination revealed faint basilar crackles but no adenopathy, skin changes, peripheral edema, dementia or focal neurologic deficit. Laboratory evaluation revealed normal renal function and a normal white blood cell count. The erythrocyte sedimentation rate was 102 mm/hr and the serum lactic dehyorogenase (LDH) was 1825 U/L (normal 105-233 U/L). PPD with anergy panel showed the patient to be anergic. FVC was 2.96 L (75% predicted), FEV1 was 1.81 L (60% predicted), and FEV1/FVC ratio of 61% on pulmonary function testing. TLC was 9.22 L (148% predicted) with a residual volume of 6.42 L (280% predicted) and diffusion capacity of 5.35 ml/min/mm Hg (20% predicted). HRCT was obtained and a heterogeneous lung opacity in a patchy or mosaic distribution consistent with mosaic perfusion was seen. Expiratory HRCT showed that the areas of low attenuation increased their attenuation with expiration by less than 50 Hounsfield units (HU) while normal-appearing lung increased by 155 HU. This was felt to be most consistent with air trapping. Fiberoptic bronchoscopy was performed and normal endobronchial mucosa was found. Transbronchial biopsies were performed of the right lower lobe. The histologic examination was significant for prominent interstitial capillary expansion within the alveoli and peribronchial tissue by a cellular infiltrate. Within the peribronchiolar tissue, the capillary expansion resulted in compression of the adjacent terminal bronchioles such that airway patency could not be established. Immunohistochemistry studies revealed positive staining in tumor cells with leukocyte common antigen and L-26 which identified the tumor as a lymphoma of B-cell lineage. The patient received 6 cycles of cyclophosphamide, doxorubicin, vincristine, and prednisone and obtained a complete clinical remission. Repeat HRCT was significant for resolution of the mosaic perfusion pattern and the serum LDH normalized at 169 U/L. The FEV1 returned to 2.94 L (98% predicted) and the diffusion capacity increased to 13.82 ml/min/mm Hg (53% predicted). He has resumed working and is disease-free at 8 month follow-up. Discussion: Mosaic perfusion on HRCT associated with airflow obstruction on pulmonary function testing is typically seen in patients with small airway diseases that result in focal air-trapping. Bronchiolitis obliterans commonly has this pattern but other diseases causing small airway obstruction such as cystic fibrosis or bronchiectasis may as well. The mosaic perfusion on HRCT is thought to be caused by reflex vasoconstriction in areas of poor ventilation resulting in areas of low attenuation. Mosaic perfusion may also be seen in patients with pulmonary vascular obstruction, usually from pulmonary embolism or simulated in patients by patchy areas of ground-glass opacity. The expiratory HRCT helps confirm the presence of air trapping by accentuating differences between normal lung and abnormal lucent lung. This case represents a unique pathophysiology where the capillary engorgement by lymphoma causes impingement of the bronchioles and air trapping. The vascular obstruction that IVL causes, however, may have contributed to the dramatic mosaic perfusion seen in our patient. Transbronchial biopsy represents a relatively noninvasive means of early diagnosis, and our case is the third reported in which the diagnosis was made by bronchoscopy.2,3 Conclusion: Pulmonary IVL may present with obstruction and air trapping on pulmonary function testing and mosaic perfusion on HRCT, particularly in the clinical setting of fever, weight loss, and night sweats. Bronchoscopy with transbronchial biopsy may allow early diagnosis relatively noninvasively. Treatment with a standard lymphoma regimen may result in a dramatic clinical response.
|Original language||English (US)|
|Issue number||4 SUPPL.|
|State||Published - Oct 1998|
ASJC Scopus subject areas
- Pulmonary and Respiratory Medicine
- Critical Care and Intensive Care Medicine
- Cardiology and Cardiovascular Medicine