Primary cutaneous melanomas seen as inflamed pigmented lesions in patients undergoing adjuvant interferon treatment: a possible diagnostic clue for physicians.

Background: In addition to a complete skin examination every few months, adjuvant interferon treatment is often recommended for patients with high-risk melanomas. Therefore, dermatologists play an important role in detecting multiple primary melanomas and may be required to attempt to identify the primary melanoma in patients with metastatic disease.
Observations: We describe 3 patients with a diagnosis of melanoma who were diagnosed as having a new primary cutaneous melanoma within weeks of initiating interferon treatment. All 3 melanomas were inflamed clinically, prompting excisional biopsy. Histopathologic analysis of the melanomas revealed thin (<1.0 mm Breslow thickness) invasive tumors, as well as the presence of tumor-infiltrating lymphocytes and/or regression.
Conclusions: Inflamed melanocytic lesions in patients undergoing interferon treatment should be further evaluated to investigate the possibility of primary cutaneous melanomas. This observation may enable earlier detection and treatment of melanomas in patients with multiple tumors or metastatic melanoma with an unknown primary site.