A 52-year-old Australian Indigenous women presented with 6 months history of dry cough. There were no other respiratory symptoms. She did not have any constitutional symptoms, in particular no history of fever, anorexia or unintentional weight loss. She denied any history or known contact for tuberculosis.
Her past medical history included Sjogren's syndrome, initially diagnosed at the age of 42 years and had clinical manifestation of sicca syndrome, xeropthalmia and xerostomia (dry eyes and dry oral cavity). She had a family history for breast cancer, Sjogren's syndrome and Systemic Lupus Erythematosus. She had a very insignificant history of smoking as a teenager. She was not on any regular medications other than NSAID for nonspecific back pain.
Physical examination was un-remarkable other than for an enlarged thyroid gland. There was no palpable lymphadenopathy, clubbing or other signs of connective tissue disease. Respiratory examination was normal, in particular there were no crackles to suggest presence of interstitial lung disease.
Laboratory examination demonstrated normal white cell/differential count. Serum electrolytes and liver function testes were also normal. Her ESR was elevated at 38mm/h, anti-nuclear antibody (ANA) titre was raised with a titre of 1:1280 demonstrating a speckled and nucleolar pattern. Extractable nuclear antigen (ENA) was positive for SS-A (Ro) and SS-B (La) and other ENA such as RNP, Sm, Scl - 70 and Jo-1 including ds-DNA antibody were negative. Thyroid function test was also normal, HIV and hepatitis serology were negative. Serum immunoglobulin showed slightly elevated IgG level at 17.7 (6.5-16.0) and IgA and IgM were normal. Pulmonary function test was normal with a Forced Vital Capacity (FVC) of 3.00L (88%), Forced Expiratory Volume in 1 second (FEV1) was 2.55L (94%) with FEV1/FVC Ratio of 0.85 (107%). The Gas transfer (DLCO) was normal at 86% and the lung volumes were preserved with Total lung Capacity (TLC) at 80% predicted respectively.
A CT of the chest performed demonstrated multiple pulmonary nodules bilaterally, including a solitary non-calcified multilobulated opacity in the right lower lobe (RLL) measuring 28 x 17 mm with slight speculation (Fig. 1). The CT scan also demonstrated multiple bilateral pulmonary cysts. (Fig. 1). There was no evidence of Interstitial Lung Disease (ILD) or hilar or mediastinal lymphadenopathy. Incidental retrosternal extension of the enlarged thyroid gland was noted. Ultra sound of the thyroid gland demonstrated benign cystic lesion. A high index for malignancy with multiple metastasis was considered in the differential diagnosis. Hence, she underwent a bronchoscopy, which did not demonstrate endobronchial abnormalities and washings were negative for malignant cells and acid-fast bacilli. Cultures were negative for Acid fast bacilli (AFB), bacterial or fungal elements. She underwent a PET scan which showed positive uptake in the right lower lobe lesion with an SUV of 4.2, suspicious for malignancy and included in the differential of possible inflammatory process (Fig. 2). A percutaneous CT guided biopsy of the right lower lobe lesion was attempted, which was unfortunately complicated by an iatrogenic pneumothorax, and the results were inconclusive. In order to make a definitive diagnosis she underwent a video assisted thoracotomy with a wedge excision of the RLL nodule. Surprisingly, the biopsy showed evidence of amorphous material and demonstrated apple-green birefringence under polarised light after staining with Congo-Red in keeping with pulmonary AL amyloidosis (Fig. 3, Fig. 4, Fig. 5). In-situ hybridisation with kappa and lambda stains showed preferential kappa staining (Fig. 3, Fig. 4, Fig. 5). Biopsy results also identified Immunoglobulin heavy chain, with rearrangement studies demonstrating polyclonal lymphocyte population in pulmonary infiltrate. Serum electrophoresis did not identify paraprotein with free light chains showing Kappa 29 mg/L (3-19), Lambda 26 mg/L (6-26) and K/L Ratio of 1.11 (0.25-1.65). In order to exclude systemic AL amyloid, patient underwent bone marrow biopsy and skeletal survey, which were normal. Her cough improved with symptomatic management. As localized AL amyloidosis has a very low likelihood of systemic dissemination she remains on surveillance and was not offered systemic treatment as she had interval symptom resolution.
PET-CT scan showing positive uptake in the right lower lobe.