CRA21 A RARE ENTITY: A CASE REPORT OF PRIMARY MALIGNANT MELANOMA OF THE LUNG

Pereira,Decena S1, Nurnazura Najwa Mohammad Din1,  Izzatul Nadzirah Ismail1
1. Medical Department, Hospital Enche Besar Hajjah Khalsom, Kluang, Johor

Introduction

Malignant melanoma is a malignant skin tumor and can originate from any part of the body. It is  high grade cancer with early metastasis. Primary extracutaneous malignant melanoma is rare and can present in various places including the lung. Primary malignant melanoma of the lung (PMML) accounts for 0.01% of all primary lung cancers. 

Objectives

This case report aims to establish the diagnosis of PMML.

Methodology

We present a case report of a 68 years old Malay gentleman who presented with cough and constitutional symptoms for 3 weeks. A detailed examination did not show any skin lesions and CXR revealed left pleural effusion. Initial pleural tapping showed exudative pattern which did not grow any organism including tuberculosis. Despite completing one course of antibiotics, he     returned with a recurrent left exudative pleural effusion for which chest drain was inserted and proceeded with CECT Thorax.

Result

CECT thorax is reported as enhancing left lower lobe lung mass measuring 5.5 x 7.8 x 7.7cm with multiple pleural based lesions in keeping with metastasis. A CT guided biopsy revealed malignant melanoma with positive immunohistochemical staining of SOX10, S100 and HMB45 that confirmed the diagnosis. Patient was planned for referral to Oncology team but unfortunately, he refused further intervention and treatment. 

Conclusion

PMML remains a rare diagnosis and difficult to diagnose because of its morphological and immunophenotypic variations. However solitary lung tumor with no pigmented skin lesions suggests a primary disease. Treatment strategies include surgery, radiotherapy, chemotherapy and also biological treatment. Unfortunately despite all treatment strategies, the outcome remains grim with 5-year survival is less than 20%.