# Expedited diagnosis of disseminated Mycobacterium kansasii infection using targeted (amplicon-based) next-generation sequencing in an immunocompromised patient

## TL;DR

A new method using sequencing helped quickly diagnose a rare infection in a patient with a weakened immune system.

## Contribution

Demonstrates the use of amplicon-based next-generation sequencing for rapid diagnosis of disseminated Mycobacterium kansasii infection.

## Key findings

- Targeted sequencing detected M. kansasii from FFPE tissue before culture confirmation.
- Amplicon-based sequencing expedites diagnosis in immunocompromised patients with complex symptoms.
- Highlights challenges in diagnosing disseminated infections with overlapping clinical features.

## Abstract

Mycobacterium kansasii is typically associated with pulmonary disease and is an uncommon cause of disseminated infection and thus can be challenging to diagnose and treat.

We present a 59-year-old female with a history of renal cell carcinoma (RCC) and T-cell large granular lymphocytic leukemia (T-LGLL) who developed disseminated Mycobacterium kansasii infection. Targeted next-generation sequencing (tNGS) facilitated the rapid detection of M. kansasii from formalin-fixed, paraffin-embedded (FFPE) tissue, aiding in clinical decision-making prior to culture confirmation.

The case highlights the diagnostic challenges posed by overlapping clinical features and chronic granulomatous inflammation in immunocompromised patients, as well as the utility of amplicon-based sequencing in expediting diagnostic turnaround and guiding therapeutic interventions.