# Cavitary Pulmonary Blastomycosis and an Incidental Retroperitoneal Ganglioneuroma Mimicking Metastatic Disease

## TL;DR

A case report describes a fungal infection and a benign tumor that together mimicked metastatic cancer in a young man.

## Contribution

The novelty lies in the rare coexistence of cavitary pulmonary blastomycosis and an incidental retroperitoneal ganglioneuroma mimicking metastatic disease.

## Key findings

- Pulmonary blastomycosis was diagnosed in a 26-year-old male with cavitary lung lesions.
- A retroperitoneal ganglioneuroma was identified as a benign incidental finding.
- The combination of findings initially raised suspicion for metastatic malignancy.

## Abstract

Pulmonary blastomycosis is a fungal infection caused by Blastomyces dermatitidis that can present with a wide range of nonspecific pulmonary findings and, in rare cases, mimic metastatic malignancy. This case report describes a 26-year-old immunocompetent male who presented with subacute respiratory symptoms and was found to have numerous cavitary pulmonary lesions and a large infiltrative retroperitoneal mass, raising concern for disseminated malignancy, with subsequent evaluation revealing pulmonary blastomycosis and an incidental benign retroperitoneal ganglioneuroma.