대한흉부영상의학회 Korean Society of Thoracic Radiology

Discussion

Diagnosis With Brief Discussion

Diagnosis

Amyloidosis

Radiologic Findings

Chest radiograph shows widening of both main bronchi, bulging contour of aorto-pulmonary window, suggesting mediastinal lymphadenopathy
Bilateral pleural effusions are also noted. Contrast enhanced chest CT shows multiple enlarged lymph nodes in the mediastinum and both hilar area.
Multiple tiny calcified nodules are also noted in both lungs. There is another incidental finding, smooth interlobular septal thickening due to interstitial pulmonary edema.

Lymph node, supracarinal, endobronchial ultrasound-guided needle biopsy - Amorphous eosiniphilic materials, consistent with amyloidisis, light (AL) chain-related,
Congo-red stain, Apple-green birefringence
Kidney, native, biopsy - Amyloidosis, light (AL) chain-related, Congo-red positive in mesangium
Bone marrow, needle biopsy - Overall 30% cellularity marrow showing small aggregation of CD 138 (+) plasma cells, consistent with plasma cell myeloma.

Brief Review

Amyloidosis is a group of diseases resulting from the extracellular accumulation of abnormal protein in tissues and organs throughout the body. Amyloid protein deposits characteristically retain the dye Congo red, giving a pathognomonic red-green birefringence when viewed with a microscope under polarized light.
Amyloidosis can be classified on the basis of its anatomic distribution or the structure of the protein deposits: systemic or localized. The biochemical classification system, according to the type of the fibrillar component in amyloid deposits, has over two dozen subtypes. The fibrillar proteins amyloid light chain (AL) and serum amyloid A (AA) are present in the vast majority of cases.

Pulmonary involvement- Pulmonary amyloidosis is more often a localized process rather than a part of systemic disease.Two patterns of involvement exist: nodular parenchymal and alveolar septal forms. Nodular parenchymal amyloidosis may manifest as solitary or multiple pulmonary nodules and may mimic a variety of diseases from granulomatous disease to malignancy. Alveolar septal pulmonary amyloidosis is characterized by well-defined 2–4-mm micronodules with some calcifications accompanied by reticular opacities, interlobbular septal thickening, and confluent consolidations with basal and peripheral predominance.

Airway involvement - It usually involves the airways diffusely and tends to result in submucosal plaques, but deposition can infrequently be solitary and mimic an endobronchial neoplasm. Usually, long-segment tracheal narrowing is encountered at imaging, which may be better appreciated on coronal and sagittal reconstructions.
Unlike tracheobronchopathia osteochondroplastica or relapsing polychondritis (which are cartilage disorders), amyloidosis may involve the tracheal posterior membrane.

Mediastinal involvement - Mediastinal involvement is most commonly seen with systemic amyloidosis and may consist of multistation lymphadenopathy or more anatomically localized involvement. Mediastinal lymphadenopathy may manifest with a variety of patterns of calcifications including punctate, diffuse, or eggshell.

References

1. Czeyda-Pommersheim F. et al, Amyloidosis: Modern Crosssectional Imaging, Radiographics. 2015 Sep-Oct;35(5):1381-92.
2. Mitchell PD. et al, A case of pulmonary amyloidosis. Thorax 2014;69(6):600.
3. Fiorelli A. et al, Isolated mediastinal amyloidosis mimicking a neoplastic lesion. Gen Thorac Cardiovasc Surg 2014;62(5):324–326.

Please refer to

Case 998 Case 985 Case 982 Case 939 Case 834 Case 794 Case 738 Case 664 Case 509 Case 478 Case 298

Keywords

Amyloidosis, Lymph node,