Unlike systemic amyloidosis, when amyloidosis is localized to the lungs, this uncommon condition usually involves the lungs in one of two ways. In can be confined to the tracheobronchial tree as single or multiple lesions, or involve the lung parenchyma as one or more nodules. It only rarely causes diffuse infiltration of the lungs. Its presence can easily be mistaken for other more serious etiologies as this case illustrates.
We present a 54 year old Caucasian female diagnosed with infiltrative ductal carcinoma of the breast in 1997. She had a lumpectomy with lymph node dissection which revealed two lymph nodes positive for cancer. She received chemotherapy and hormonal therapy. Radiation therapy was not given because of an underlying diagnosis of SLE. She was diagnosed with SLE and Sjogren’s syndrome in 1990 at which time she had renal involvement and received cyclophosphamide for six months followed by azathioprine. More recently she has been on methotrexate and hydroxychloroquine. She was referred to us after a chest radiograph and CT of the chest showed right middle lobe airspace disease and multiple nodules throughout both lung fields that were highly suspicious for metastatic breast carcinoma. This was evaluated previously at another hospital where she had a bronchoscopy that revealed atypical cells. She subsequently underwent open lung biopsy, which reported patchy lymphoid aggregates and chronic inflammation. We obtained these biopsies taken from the right middle lobe and lower lobe. The biopsies demonstrated a waxy nodular material. Alkaline Congo Red stain of this material was positive for apple-green birefringence under polarized light that was consistent with pulmonary nodular amyloidosis. It also showed evidence of lymphoid hyperplasia and follicular bronchiolitis consistent with her connective tissue disease. There were emphysematous changes compatible with her past 30-40 pack year smoking history and moderate airways obstruction noted on pulmonary function testing.
Amyloidosis is usually systemic in nature and when it involves the lungs it is diffuse, infiltrative, and asymptomatic. It is can be idiopathic in nature, hereditary, or associated with underlying inflammatory or hematologic disorders such as myeloma. Pulmonary nodular amyloidosis, though rare, is limited to the lungs. An extensive evaluation looking for other predisposing causes for amyloidosis was negative, as was the evaluation looking for other organ involvement, including core biopsy of the abdominal fat pad. Pulmonary nodular amyloidosis is a rare condition, and even more uncommonly it has been associated with Sjogren’s syndrome. The few reports describe it as cystic changes, lymphoplasmocytic infiltrates, or irregular noncavitary nodules. In this particular case, the appearance was compatible with metastatic disease as well as a possible drug reaction.
Pulmonary nodular amyloidosis can mimic other more serious entities such as metastatic breast cancer as in this case. It can be missed on histopathology unless it is considered in the differential and special stains are performed. The nodular distribution suggests it is not secondary to the often more life threatening causes of systemic amyloidosis which include malignant disorders. This patient’s Sjogren’s syndrome was the most likely condition that predisposed her to develop this rare complication of this disease.
Maria Carrillo, None.