Pulmonary amyloidosis associated with Sjogren’s syndrome

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Case Summary

A 75-year-old woman with a history of primary Sjogren’s syndrome developed dyspnea. A CT scan of the chest revealed lung nodules, which were sampled and found to be pulmonary amyloidomas with a peptide profile of AL (k) type amyloid.

Imaging Findings

A CT scan of the chest without contrast demonstrated several relatively well circumscribed calcified and ground glass nodules measuring up to 2.7 cm in size. The differential diagnosis for these nodules includes atypical adenomatous hyperplasia, which is a precursor to adenocarcinoma of the lung, lymphoma and amyloid nodules. The presence of calcification within a nonsolid nodule is most consistent with amyloid nodules.¹

There are mild fibrotic changes of the lung parenchyma, which follow the bronchovascular bundles. In addition, there are many thin-walled cysts extending deep into the lung parenchyma in the upper and lower lobes (Figure 1, click for DICOM viewer). The differential diagnosis of interstitial lung disease that follows the bronchovasular bundles includes nonspecific interstitial pneumonitis, chronic hypersensitivity pneumonitis, and lymphocytic interstitial pneumonia .

Air cysts within the lungs can be seen in several processes, including lymphangioleiomyomatosis, Langerhan’s cell histiocytosis and lymphocytic interstitial pneumonia.² The combination of imaging findings in a patient with known Sjogren’s syndrome represents lymphocytic interstitial pneumonia and amyloid nodules.

Diagnosis

AL (k) amyloidosis and lymphoid interstitial pneumonia associated with Sjogren’s disease

Discussion

Amyloidosis occurs due to the excess formation of certain proteins, and as a result, the organ that suffers from overexpression malfunction. In AL amyloidosis, the faulty protein subunit is a monoclonal immunoglobulin: к or λ light chains. The incidence of this disease in America is 4.5 per 100,000. Nodular opacities, diffuse opacities and tracheobronchial disease are the three different types of localized AL amyloid diseases. Nodular opacities are typically present in the lower lobes at the periphery and can potentially grow. Diffuse opacities are rarely witnessed, and they are typically found in one lung. In tracheobronchial disease, two types of patterns can occur: nodular disease and submucosal disease.³

Sjogren’s syndrome is an autoimmune disease in which lymphocytes are believed to attack glands of the body that generate saliva and tears.⁴ It is recognized as the second-most widespread autoimmune disease. Patients suffer from severe dryness of the eyes and mouth and muscles aches, leading to fatigue. This syndrome has the potential to cause life-threatening disease in the lungs, heart, kidneys and nerves. More specifically, Sjogren’s syndrome is related to several lung diseases: pulmonary amyloidosis, interstitial lung disease and xerotrachea.⁵

Lymphoid interstitial pneumonia (LIP) is considered an idiopathic interstitial lung disease, yet it is suspected to have an autoimmune origin because it is associated with other autoimmune diseases like rheumatoid arthritis and Sjogren’s syndrome.⁶ Approximately 25% of patients with LIP suffer from Sjogren’s syndrome. LIP also commonly develops in patients with HIV. On chest imaging the lungs have reticular opacities in the bases, ground glass opacities and cysts in later stages of the disease.

Rarely, Sjogren’s syndrome and AL amyloidosis can exist together.⁷ Women are more commonly afflicted. Patients may present with dyspnea, cough and fatigue. Other complications include Raynaud’s phenomenon, thrombocytopenia and lymphoma. Sjogren’s syndrome is also related to lymphoid interstitial pneumonitis. The typical radiographic presentation consists of cysts of different sizes. Although there is no cure for these diseases, corticosteroids can be used to alleviate the symptoms.^6,7

Conclusion

The combined diagnosis of Sjogren’s syndrome and AL amyloidosis is uncommon, but it is essential that physicians consider the possibility of amyloidosis in patients with known Sjogren’s syndrome. In addition, lymphoid interstitial pneumonitis is associated with Sjogren’s syndrome. This case illustrates the imaging findings of a patient with Sjogren’s syndrome, AL amyloidosis and lymphoid interstitial pneumonitis, along with their associations with one another.

References

1. Viera IG, Marchiori E, Zanetti G, et al. Pulmonary amyloidosis with calcified nodules and masses-a six-year computed tomography follow-up: a case report. Cases Journal.2009;2:6540.
2. Johkoh T, Muller N, Pickford HA, et al. Lymphocytic interstitial pneumonia: Thin section CT findings in 22 patients. Radiology. 1999;212(2):567-572.
3. Berk JL, O’Regan A, Skinner M. Pulmonary and trachebronchial amyloidosis. Seminars in Respiratory and Critical Care Medicine. 2002;23(2):155-165.
4. Patel R, Shahane A. The epidemiology of Sjogren’s syndrome. Clinical Epidemiology. 2014; 6:247-255.
5. Constantopoulos SH, Drosos AA, Maddison PJ, et al. Xerotrachea and interstitial lung disease in primary Sjogren’s syndrome. Respiration. 1984;46:310-314.
6. Swigris JJ, Berry G J, Raffin TA, et al. Lymphoid interstitial pneumonia: A narrative review. Chest Journal. 2002; 122(6):2150-2164.
7. Rajagopala S, Singh N, Gupta K, et al. Pulmonary amyloidosis in Sjogren’s syndrome: A case report and systematic review of the literature. Official Journal of the Asian Pacific Society of Respirology. 2010;15(5):860-866.