Tuberculosis of abdominal lymph nodes, peritoneum, and GI tract: a malignancy mimic

Distinguishing multiple roles of T cell and macrophage involvement in determining lymph node fates during Mycobacterium tuberculosis infection

Tuberculosis (TB) is a disease of major public health concern with an estimated one-fourth of the world currently infected with M. tuberculosis (Mtb) bacilli. Mtb infection occurs after inhalation of Mtb, following which, highly structured immune structures called granulomas form within lungs to immunologically restrain and physically constrain spread of infection. Most lung granulomas are successful at controlling or even eliminating their bacterial loads, but others fail to control infection and promote disease. Granulomas also form within lung-draining lymph nodes (LNs), variably affecting immune function. Both lung and LN granulomas vary widely in ability to control infection, even within a single host, with outcomes ranging from bacterial clearance to uncontrolled bacterial growth. While lung granulomas are well-studied, data on LN granulomas are scarce; it is unknown what mechanisms drive LN Mtb infection progression and variability in severity. Recent data suggest that LN granulomas are niches for bacterial replication and can reduce control over lung infection. To identify mechanisms driving LN Mtb infection, we developed a multi-scale compartmental model that includes multiple lung-draining LNs, blood. We calibrated to data from a nonhuman primate TB model (one of the only models that parallels human TB infection). Our model predicts temporal trajectories for LN macrophage, T-cell, and Mtb populations during simulated Mtb infection. We also predict a clinically measurable infection feature from PET/CT imaging, FDG avidity. Using uncertainty and sensitivity analysis methods, we identify key mechanisms driving LN granuloma fate, T-cell efflux rates from LNs, and a role for LNs in pulmonary infection control.

Multisystem diseases in the abdomen and pelvis: imaging manifestations and diagnostic roles of cross-sectional imaging

Systemic diseases, such as IgG4-related disease, sarcoidosis, and amyloidosis, usually involve multiple systems or organs simultaneously or sequentially. The gastrointestinal tract, hepatobiliary system, and genitourinary tract are commonly involved in many multisystem diseases and can also be the first sites with disease involvement. Cross-sectional imaging, such as CT and MR, plays an important role in the diagnosis and management of multisystem diseases by aiding in the evaluation of multiorgan involvement. Here, common imaging features of frequently affected organs are reviewed in multisystem diseases that we often encounter in the abdomen and pelvis, and the diagnostic roles of cross-sectional imaging for these diseases are also discussed.

Multimodality imaging of urinary tract tuberculosis

Imaging is a key component of diagnosis and treatment response evaluation of urinary tract tuberculosis (UT TB). Tuberculosis can have a long latency, but if found early, one may have the opportunity to prevent complications such as ureteral strictures, obstructive nephropathy, contracted (thimble) bladder, renal parenchymal destruction/calcification, and renal failure. Imaging can aid in diagnosis and differential diagnoses, evaluate the extent of disease and complications, and guide image-directed biopsy, surgical planning, and evaluation of treatment response. Imaging abnormalities in the renal parenchyma and urinary tract at different stages of the disease, lymphadenopathy, and extra-urinary tract organ involvement are suggestive of UT TB. Recent advances in imaging modalities aid in UT TB diagnosis, follow-up, and guiding treatment.

Comments and Illustrations of Ultrasound Findings in Extrapulmonary Tuberculosis Manifestations

This review describes the appearance of extrapulmonary tuberculosis manifestations in comprehensive and multiparametric ultrasound imaging. The aim is to increase awareness of typical ultrasound findings regarding extrapulmonary tuberculosis, correlate those with pathological features, and facilitate differential diagnosis. Point of care ultrasound protocols can be used as a screening method in high-risk populations, although the negative findings do not exclude tuberculosis. Conversely, the diagnosis of extrapulmonary tuberculosis can never be made using ultrasound alone, as many ultrasound findings in extrapulmonary tuberculosis are non-specific. However, ultrasound-based sampling techniques can significantly facilitate the collection of samples for microbiological or molecular proof of tuberculosis, as well as facilitating the establishment of alternative diagnoses.

Abdominal visceral tuberculosis: a malignancy mimic

The purpose is to discuss abdominal tuberculosis mimicking malignancy involving the abdominal viscera. TB of the abdominal viscera is common, especially in countries where tuberculosis is endemic and in pockets of non-endemic countries. Diagnosis is challenging as clinical presentations are often non-specific. Tissue sampling may be necessary for definitive diagnosis. Awareness of the early and late disease imaging appearances of abdominal tuberculosis involving the viscera that can mimic malignancy can aid detecting TB, providing a differential diagnosis, assessing extent of spread, guiding biopsy, and evaluating response.