Visceral lesions occurring during follow-up of melanoma patients: A true place for other diagnosis than melanoma metastasis

Background Diagnosis of melanoma metastasis is often based on a combination of clinical and radiological examinations in patients with a past history of melanoma. Chemotherapeutic treatment is often proposed without histological proof of the metastatic status. Objective The aim of this study was to investigate a cohort of melanoma patients with invasive diagnostic procedures (IDPs) for pathological confirmation of metastasis in case of suspicious visceral lesions. Methods A total of 109 melanoma patients with IDPs for suspicious visceral lesion(s) were included. Data about primary melanoma, IDPs characteristics, pathological result and therapeutic consequence were collected. Patients with AJCC Stage I-III melanoma at the time of the IDP were statistically analysed for various characteristics according to the final diagnosis yielded by the IDP. Results A total of 64 diagnostic surgical resections, 38 CT-guided core-needle biopsies, 15 ultrasound-guided core-needle biopsies, 6 surgical biopsies and 6 per-endoscopic biopsies were performed. Main target organs were the lungs (43.5%), breasts (8.5%) and liver (8%). IDPs were well tolerated and provided adequate samples for reliable diagnoses. Among the 105 IDPs in stage I-III patients, 56 melanoma metastases (53%), 25 benign lesions (24%) and 23 other cancers (22%) were found. One IDP was not informative. Multivariate analysis showed that nodular type of the primary melanoma, time-lag between primary melanoma and IDP over 12 months and the presence of suspicious lesions outside the organ biopsied were significantly associated with melanoma metastasis diagnosis. Conclusion Suspected melanoma metastasis was ruled out for benign lesion or second cancer in nearly half of the stage I-III patients having undergone an IDP, therefore modifying the medical treatment.