# Timely and Accurate Diagnosis of Rare Metastatic Melanoma With Pulmonary Vascular, Cardiac, and Brain Involvement: Improving Diagnostic Access and Minimising Risk

## TL;DR

A patient with rare metastatic melanoma involving the heart, lungs, and brain was diagnosed using advanced imaging and a minimally invasive bronchoscopic biopsy, enabling timely immunotherapy treatment.

## Contribution

Demonstrates the effectiveness of PET-CT and EBUS in diagnosing complex metastatic melanoma with multi-organ involvement.

## Key findings

- PET-CT distinguished tumour thrombus from embolic disease in a high-risk patient.
- Endobronchial ultrasound provided a safe and effective tissue diagnosis of BRAF-positive metastatic melanoma.
- Immunotherapy with ipilimumab and nivolumab was well tolerated and showed a favorable response.

## Abstract

We present a patient in his 40s with a history of melanoma excised 14 years prior, who developed persistent cough, haemoptysis, and chest pain. Imaging revealed a right hilar mass extending into the pulmonary artery and left atrium. PET-CT confirmed high 18F-fluorodeoxyglucose (FDG) uptake consistent with active tumour, while brain MRI showed metastatic lesions and cardiac MRI revealed intracardiac extension. An initial CT-guided lung biopsy was non-diagnostic. Due to diagnostic uncertainty, full anticoagulation (given the difficulty in distinguishing tumour from thromboembolism), and high procedural risk, endobronchial ultrasound (EBUS) was performed under conscious sedation. EBUS successfully provided a tissue diagnosis of BRAF-positive metastatic melanoma. The patient was initiated on ipilimumab and nivolumab immunotherapy, which was well tolerated with a favourable response. This case illustrates the critical role of PET-CT in distinguishing tumour thrombus from embolic disease and demonstrates the value of EBUS as a minimally invasive, safe, and effective diagnostic tool in high-risk settings. It also highlights how perseverance in diagnostic efforts can facilitate early treatment, even in complex and high-risk scenarios.