Disease: Pulmonary Amyloidosis, probably secondary
This 73 y/o white female presented with a history of
increasing SOB and diffuse parenchymal lung disease on chest
radiographs.Initial transbronchial biopsy showed nonspecific
mild focal chronic inflammation .She was placed on colchicine
therapy, but had progression of her interstitial lung disease
by CXR. Repeat transbronchial biopsy was positive for congo
red, consistent with pulmonary amyloidosis. Additional
workup revealed a diffuse hypogammaglobulinemia, negative
ANA, and elevated urine protein with sharp gamma spike (kappa
light chain). She was presumed to suffer from pulmonary
amyloidosis secondary to Multiple Myeloma, although she
expired prior to definitive diagnosis of her light-chain
Her CXR shows diminished lung
volumes with diffuse bilateralreticulonodular opacities.
CT images reveal diffuse
septalthickening with air-space opacities in both
lungs. Subtle nodule formation is seen in all five lobes, but
no honeycombing. This patient has mediastinal and hilar
lymphadenopathy as well.
Amyloidosis is characterized by proteinaceous deposits in
extracellular tissue and is classified into five main
groups: primary, secondary, localized, familial, and senile.
Any of these may affect the lungs. Lung involvement may be
any of three forms: tracheobronchial, nodular, or diffuse
parenchymal. More than one type will not usually coexist.
Tracheobronchial amyloidosis is most common and presents as
multiple nodules protruding from the wall of the trachea or
bronchi, possibly causing narrowing of the lumen. Diffuse
parenchymal form (also called diffuse alveolar septal) can
involve both lungs diffusely or regionally with interstitial
small irregular densities which may become confluent or lead
to honeycombing (CXR may also be normal). This form is least
common but is most likely to cause respiratory failure (as
with this patient). The nodular form usually occurs in
patients over 60 y/o who are generally asymptomatic until
the disease is extensive. Unlike the previously mentioned
forms of pulmonary amyloidosis, other organs are generally
not involved. Nodules are usually peripheral, and when
multiple, vary in size and shape and may calcify.
Differential Diagnosis (DDx):
DDx for the nodular type includes metastatic disease,
granulomatous disease, rheumatoid, sarcoidosis, and mucoid
DDx for the diffuse parenchymal type includes idiopathic
interstitial fibrosis, miliary tuberculosis, hypersensitivity
pneumonitis, pnemoconiosis (especially asbestosis),
rheumatoid lung, pulmonary histiocytosis X, and
DDx for the tracheobronchial type would include granulomatous
disease, broncholith, or bronchogenic carcinoma.
Graham CM, Stern EJ, Finkbeiner WE, Webb WR. High
ResolutionCT appearance of diffuse alveolar septal
amyloidosis.AJR 1992; 158:265-7.
Cordier JF, Loire R, Brune J. Amyloidosis of the lower
respiratorytract: clinical and pathological features in a
series of 21 patients.Chest 1986; 90:827-831.
Case contributed by Jill Vecchio, MD, and Debra Dyer,
Debra Dyer, MD