A 77-year-old man with a history of abnormal chest radiography finding was referred to our hospital.
The patient had hypertension, dyslipidemia, and an operative history (total resection for prostate cancer). He had a 20-pack-year smoking history but no family history of connective tissue and pulmonary diseases.
Laboratory examination showed the following: Krebs von den Lungen-6 level, 10726 U/mL; surfactant protein-D, 302 ng/mL; positivity for anti-nuclear antibody (1:320, nucleolar pattern); and negativity for anti-scl-70 antibody, anti-RNA polymerase 3 antibody, and anti-centromere antibody.
Chest radiography revealed ground-glass opacity in the bilateral lower lung fields, and a chest computed tomography scan revealed ground-glass opacity in the basal area of both lungs and a nodule in the left lower lobe (Fig. 1). The pulmonary function test result was normal.
Flexible bronchoscopy revealed normal intraluminal findings. Following this, a 51% recovery rate was achieved using bronchoalveolar lavage from the superior lingular segment; it indicated 59% lymphocytes and no malignant cells. The finding of hyperlymphocytosis in bronchoalveolar lavage fluid was considered primarily due to the etiology of ILD. Culture samples collected using bronchoscopy tested negative for common bacteria, mycobacteria, and fungus. Prior to TBLC, we introduced a 1.4-mm 20-MHz radial probe (PB2020-M; Fujifilm) with a guide sheath into the target bronchus and checked whether any blood vessel ran parallel to the bronchus. We obtained the endobronchial ultrasonographic view of "adjacent to the lesion" from B9a. We performed TBLC with a 1.9 x 1150-mm flexible cryoprobe (ERBECRYO 2 system; Erbe Elektromedizin GmbH, Tubingen, Germany) introduced through the guide sheath using an endobronchial balloon as an endobronchial blocker. Freezing time was set as 6 s. There was minor bleeding, which was easily controlled with an endobronchial blocker and an intrabronchial injection of an epinephrine-saline mixture (1-mL epinephrine with 19-mL saline). On high-resolution computed tomography (HRCT), the nodule was located in the left lateral basal segment (S9), and the TBLC sites were left B8b, B9a, and B9b. The pathological findings of the TBLC-collected specimen from left B9a showed the deposition of Congo red-stained AL with birefringence under polarized light (Fig. 2A-C). Except for the lesion of pulmonary amyloidosis, ground-glass opacities in both lungs were diagnosed as interstitial pneumonia, most likely due to chronic hypersensitivity pneumonia or interstitial pneumonia with autoimmune features. An additional biopsy was performed using bone marrow and subcutaneous adipose tissue samples, and the result was negative. Hence, the patient was diagnosed with localized nodular pulmonary amyloidosis. Since the condition was asymptomatic, he refused medical intervention. During follow-ups, he was found to have a good clinical condition.
Chest computed tomography scan revealed ground-glass opacity in the basal area of both lungs and nodule in the left lower lobe.