# Pulmonary Tropheryma whipplei Infection Presenting With Multiple Thick‐Walled Cavities on Chest CT: A Case Report and Literature Review

## TL;DR

A rare case of lung infection caused by Tropheryma whipplei is reported, diagnosed using advanced sequencing and successfully treated with doxycycline.

## Contribution

This case report highlights the diagnostic utility of metagenomic next-generation sequencing for rare infections and the effectiveness of oral doxycycline.

## Key findings

- Pulmonary Tropheryma whipplei infection presented with multiple thick-walled cavities on chest CT.
- Metagenomic next-generation sequencing of bronchoalveolar lavage fluid confirmed the diagnosis.
- Oral doxycycline treatment led to complete resolution of pulmonary cavities.

## Abstract

Whipple's disease (WD) is a rare chronic multisystem infectious disease caused by the actinomycete
Tropheryma whipplei
. Pulmonary involvement is uncommon, and its clinical manifestations lack specificity, with diverse imaging findings, making it prone to misdiagnosis. We report a rare case of a 50‐year‐old woman who presented with a 2‐week history of cough. Chest CT showed multiple thick‐walled cavities in both lungs, a highly unusual presentation for WD pneumonia. Routine microbiological tests, including acid‐fast staining and culture of bronchoalveolar lavage fluid (BALF), were negative, which made the diagnosis challenging. Metagenomic next‐generation sequencing (mNGS) of BALF detected
T. whipplei
, confirming the diagnosis of WD pneumonia. After oral doxycycline treatment, follow‐up chest CT showed complete resolution of the pulmonary cavities. This case demonstrates that multiple thick‐walled cavities may be a characteristic imaging manifestation of WD pneumonia, highlights the diagnostic value of mNGS for this rare infection, and supports oral doxycycline monotherapy as an effective treatment option for isolated pulmonary TW infection.

This case report highlights a rare instance of pulmonary infection caused by
Tropheryma whipplei
, presenting with distinctive imaging features on chest CT: multiple round or oval thick‐walled consolidations with small central cavities (approximately 1 mm in diameter) and subpleural distribution. The diagnosis was confirmed through metagenomic next‐generation sequencing of bronchoalveolar lavage fluid, and effective treatment was achieved with oral doxycycline.