Tree-in-bud Pattern on Thoracic CT due to Pulmonary Intravascular Metastases From Pancreatic Adenocarcinoma

Abstract

We report a case of pulmonary intravascular metastases from pancreatic adenocarcinoma manifesting as tree-in-bud pattern on thoracic computed tomography. Although infectious bronchiolitis is the most common cause of tree-in-bud pattern, this case emphasizes that the differential diagnoses include pulmonary intravascular metastases, particularly in patients with extrapulmonary adenocarcinomas.

Tree-in-Bud Pattern of Pulmonary Tuberculosis on Thin-Section CT: Pathological Implications

“…Metastatic tumor within the pulmonary artery, either by tumor itself ( 8 10 ) or following thrombotic microangiopathy ( 9 ), may show centrilobular branching structures, commonly with an undulated margin and varied thickness, resembling a vascular tree-in-bud pattern. However, the vascular causes of tree-in-bud morphology may reasonably lack the bud portion of the tree-in-bud.…”

“…However, the vascular causes of tree-in-bud morphology may reasonably lack the bud portion of the tree-in-bud. Tumor infiltration in the centrilobular peribronchovascular interstitium may also mimic a tree-in-bud pattern ( 10 11 ).…”

“…Since the initial report of endobronchial spread of pulmonary tuberculosis ( 1 ), the “tree-in-bud sign” has been reported in a wide variety of health conditions including infectious diseases, aspiration pneumonia, congenital disorders, idiopathic disorders, inhalation, immunologic disorders, connective disorders ( 2 3 4 5 6 ) and central lung cancer involving the peripheral airways ( 7 ). Subsequently, metastatic diseases showing “tree-in-bud sign” caused by tumor cells in and around the intralobular pulmonary artery were also reported ( 8 9 10 11 ).…”