Diagnosis and Pattern Identification of Intrathoracic Malignant Melanoma Metastasis: A Retrospective Single Center Analysis

The lung is a frequent site of secondary malignancies. Melanoma is a malignant tumor originating from melanocytes, that accounts for the majority of death related to skin cancers. In advanced stages, it can also present with intrathoracic metastasis, particularly in the lungs, but infrequent intrathoracic manifestations are possible. A retrospective analysis of the cases referred to the pulmonary endoscopy unit of the hospital of Reggio Emilia in the last 10 years (since December 2012) was carried out, discovering 17 cases of melanoma metastasis with thoracic localizations, either with or without a diagnosis of primary melanoma. Four repetitive patterns of clinical-radiological presentation have been identified and described through the same number of paradigmatic clinical cases: nodal involvement (35%), lung mass(es) (41%), diffuse pulmonary involvement (12%), and pleural involvement (12%). These different presentations imply the use of different diagnostic techniques, with an overall high diagnostic yield (87.5%). Finally, a brief analysis of survival based on the pattern of presentation has been performed, finding no statistically significant differences between the four groups at metastasis diagnosis (p-value = 0.06, median survival of respectively 54, 8, 9, and 26 months from metastasis diagnosis), while there is a significant difference considering patients with lung involvement versus nodal/pleural involvement (p = 0.01).