Metastatic melanoma - lungs

Case contributed by Bruno Di Muzio


Chest pain. Smoker.

Patient Data

Age: 60 years
Gender: Male

CT Chest, Abdomen, and Pelvis


There are bilateral well-defined solid lung masses, two on the left lower lobe and one in the right upper lobe. Small left-sided pleural effusion without clear pleural nodularity. No mediastinal lymphadenopathy. 

In the abdomen, there is a solid well-defined mass left pelvic side-wall/extraperitoneal mass. The remainder of the study is unremarkable. 


Nuclear medicine

18FDG-PET/CT confirms the lesions on CT to be extremely avid, with the large lung lesions showing a doughnut appearance likely due to central necrosis. 


  • A. Labeled "Left lung". Tan core biopsy 15mm. 
  • B. Labeled "Left lung". Tan core biopsy 13mm. 

Microscopy: A-B. Sections through both specimens show similar features and show tissue cores effaced by a population of highly atypical spindled to epithelioid cells arranged in a background of fibrosis and extravasated brown pigment.  The cells have hyperchromatic ovoid to spindled nuclei with irregular nuclear membranes and variably prominent round, eosinophilic nucleoli. Many cells show intranuclear pseudoinclusions. Within some cells, discernible cytoplasm is vacuolated or pigmented.  There is an accompanying infiltrate of pigment-laden macrophage.

Conclusion: Left lung, core biopsies:  Malignant neoplasm, showing morphological features consistent with metastatic melanoma.



Case Discussion

This case illustrates the presentation of melanoma as large bilateral lung masses. It is interesting to note the rounded appearances of the lung masses, which are also large and have central necrotic areas. Also, the absence of mediastinal nodal disease and the isolated left pelvic sidewall metastasis would be atypical for a lung primary. 

The diagnostic was confirmed with a CT-guided lung biopsy of the left lower lobe lesion. The patient had a previous history of melanoma treated years ago. 

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