[Pulmonary malignant melanoma: primary or metastatic?].

Area of Science:

• Oncology
• Pulmonology
• Medical Imaging

Background:

• Primary pulmonary malignant melanoma is exceedingly rare, accounting for 0.01% of lung cancers, with only 25 documented cases.
• Diagnosis remains controversial, often challenging due to its rarity and the need to differentiate from metastatic melanoma, relying heavily on the Jensen criteria.
• The pathogenesis of primary pulmonary melanoma is not well understood.

Observation:

• A case report of an asymptomatic 82-year-old male incidentally diagnosed with primary pulmonary malignant melanoma.
• The patient met the Jensen criteria for diagnosis and underwent successful lobectomy (cT1N0M0).
• This is the first report detailing the use and results of 18F-FDG PET-CT (standard and whole-body) in a primary pulmonary melanoma case.

Findings:

• Surgical resection is considered the gold standard treatment due to melanoma's limited response to chemotherapy and radiotherapy.
• The patient's successful surgical resection and absence of nodal involvement suggest a potentially good prognosis, though statistical data is limited.
• The study investigates the potential role of 18F-FDG PET-CT as a diagnostic tool, observing no increased uptake in this case.

Implications:

• The findings suggest that 18F-FDG PET-CT, particularly whole-body imaging, could potentially serve as an additional diagnostic criterion for primary pulmonary melanoma.
• Further research is warranted to validate the utility of 18F-FDG PET-CT in diagnosing and staging this rare condition.
• This case highlights the importance of adhering to diagnostic criteria and exploring advanced imaging techniques for rare pulmonary malignancies.