noduläre pulmonale Amyloidose

Nodular pulmonary amyloidosis is a subtype of pulmonary amyloidosis. It is considered a limited form of amyloidosis polarized by one or more intrapulmonary nodules or masses (amyloidomas).

Epidemiology

Albeit rare in general it is commoner than the diffuse parenchymal form. The incidence is thought to peak around the 6 decade of life .

Clinical presentation

Patients are usually asymptomatic. Some may rarely present with a cough or shortness of breath.

Pathology

There is nodular deposition of amyloid within the lungs. Amyloid is an inert, proteinaceous, homogeneous, acellular, and eosinophilic material.

Histology

When subjected to histochemical staining with Congo red shows green birefringence under polarized light.

Location

Nodular amyloid deposits usually appear in multiple sites; focal deposits are much less common.

Amyloid nodules usually tend to be localized to the lower lobes and towards the peripheral and subpleural areas

Associations

Nodular pulmonary amyloidosis has been reported in Sjogren syndrome with lymphocytic interstitial pneumonitis .

Radiographic features

CT

Four characteristic features have been described on CT :

• sharp, smooth and lobulated contours
• calcification
  • often central or in an irregular pattern within the nodule
  • seen in ~50% of cases
• variable shapes and sizes: 0.5-15 cm
• slow growth: often over the years and with no regression

Associated cavitation has been described but is very rare.

Very rarely, lung cysts can also form (most often described with localized amyloidosis in association with Sjögren syndrome) .

Treatment and prognosis

Management options are dependent on the severity of symptoms where asymptomatic patients usually do not require treatment. In some situations they are resected which can be both diagnostic and curative .

Differential diagnosis

Nodular pulmonary amyloidosis is a great mimicker of various entities which include:

• primary or metastatic malignant nodules
• granulomatous disease
  • pulmonary manifestations of tuberculosis
  • pulmonary manifestations of sarcoidosis
• silicosis 
• multiple pulmonary hamartomas

For a broader differential consider:

• differential diagnosis of calcified pulmonary densities

A tissue biopsy is deemed to be essential for a definitive diagnosis.

See also

• amyloidosis
• pulmonary amyloidosis

Siehe auch:

• Silikose
• pulmonale Tuberkulose
• pulmonale und mediastinale Sarcoidose
• Amyloidose
• pulmonales Hamartom
• Amyloidose der Lunge
• differential diagnosis of calcified pulmonary densities
• cerebral amyloidoma
• diffuse pulmonale Amyloidose

und weiter:

• perilymphatische Lungennoduli
• AL amyloidosis