CT-guided biopsy in the differential diagnosis of Sjogren syndrome associated cystic lung disease: A case of lung nodular AL-k amyloidosis

Pulmonary involvement in Sjogren syndrome (SS) could manifest as cystic lung disease (CLD). CLD in SS includes lymphocytic interstitial pneumonia (LIP) and pulmonary amyloidosis. Differential diagnosis usually requires surgical lung biopsy, whereas CT-guided percutaneous fine needle aspiration biopsy (CT-FNAB) has not yet explored. We describe the case of a 63-year-old never smoker Caucasian female with a SS diagnosis who displayed a newly detected diffuse CLD at high-resolution computed tomography, though totally asymptomatic. Given the favorable location of one big lesion at the superior left lobe, a CT-FNAB was proposed instead of a more invasive SLB. At histology examination a diagnosis of pulmonary nodular AL kappa amyloidosis in the context of SS was established. In conclusion, CT-FNAB might represent an alternative and less invasive diagnostic procedure than SLB in the differential diagnosis of CLD, even if further research is needed. Moreover, this case presents an unusual association between SS and pulmonary nodular AL kappa amyloidosis, with pulmonary nodules and cysts without systemic manifestations.