Morphological Diversity and Diagnostic Evaluation of Thoracic Amyloidosis: Insights From a Tertiary Referral Center in Vietnam.

BACKGROUND

Thoracic amyloidosis is a rare disorder that often mimics malignancy or chronic infections. In tuberculosis-endemic regions, diagnostic confusion frequently leads to unnecessary empiric treatments. This study was aimed at describing the clinical and radiological characteristics of thoracic amyloidosis and evaluating the safety profile of diagnostic biopsy procedures.

METHODS

We retrospectively analyzed 19 patients with histopathologically confirmed thoracic amyloidosis at the National Lung Hospital, Hanoi, Vietnam, between 2022 and 2025. Clinical symptoms, high-resolution computed tomography (CT) features, and biopsy outcomes were recorded.

RESULTS

The mean age was 55 ± 16 years. Common symptoms included cough (n = 15, 88.2%) and dyspnea (n = 9, 52.9%). Isolated airway involvement was the most frequent phenotype (n = 6, 31.6%), followed by isolated nodular (n = 3, 15.8%) and diffuse alveolar septal (n = 2, 10.5%) patterns. Mixed radiological patterns were observed in five patients (26.3%), while isolated extrapulmonary thoracic involvement accounted for the remaining three patients (15.8%). Notably, isolated cystic disease was absent. Among the cases with nodular involvement (n = 5), 80.0% (n = 4) exhibited spiculated margins, mimicking malignancy. Calcification was a frequent finding, present in 14/19 cases (73.7%). CT-guided transthoracic needle biopsy (TTNB) and endobronchial biopsy (EBB) achieved diagnostic yields of 87.5% (7/8) and 69.2% (9/13), respectively, with no major complications, suggesting they are generally well-tolerated. All collected specimens were negative for Mycobacterium tuberculosis, reducing the likelihood of active pulmonary tuberculosis.

CONCLUSIONS

Thoracic amyloidosis presents with diverse and often overlapping radiological patterns. Isolated nodular lesions frequently exhibit spiculated margins, posing a diagnostic challenge. However, the high prevalence of calcification and the acceptable safety profile of EBB and TTNB facilitate definitive diagnosis. In endemic areas, early tissue diagnosis is essential to differentiate amyloidosis from tuberculosis and avoid inappropriate therapy.