Malignant Melanoma in a Retrospective Cohort of Immunocompromised Patients: A Statistical and Pathologic Analysis

SIMPLE SUMMARY: Despite recent advances in immunotherapy, melanoma remains the deadliest cutaneous malignancy. Immunocompromised patients are at heightened risk of developing melanoma and experience greater levels of morbidity and mortality compared to their non-immunocompromised peers with the disease. We sought to characterize immunocompromised patients with melanoma at our institution in terms of histopathologic parameters, trends in survival analysis, and comparison to the general population using the Surveillance, Epidemiology, and End Results (SEER) database. Analysis of our transplant sub-cohort revealed an overall melanoma standardized incidence ratio of 1.53, though variation was seen based on transplant type, sex, and time since transplantation. Our study reveals important trends in disease among immunocompromised patients with melanoma at an academic tertiary-care center and is valuable for clinicians caring for this unique demographic of patients. ABSTRACT: Background: Malignant melanoma is the leading cause of death due to cutaneous malignancy. Immunocompromised individuals have an elevated risk of developing melanoma. We aimed to provide histopathologic and statistical characterization of melanoma development in immunocompromised patients. Methods: We reviewed our institution’s databases to identify all patients with a confirmed history of immunosuppression who subsequently developed melanoma, focusing on diagnoses during the follow-up period of 2011–2019. A total of 93 patients with a combined 111 melanoma lesions were identified. Results: Common causes of immunosuppression included transplantation and lymphoproliferative disorders. Superficial spreading and lentigo malignant melanoma were the most common malignant melanoma subtypes. Median Breslow depth was 0.7 mm, and the most common primary tumor stage was T1a. Our transplant sub-cohort had an overall melanoma incidence of 0.9 per 1000 person-years (95% CI 0.66 to 1.20) and a standardized incidence ratio (SIR) of 1.53 (95% CI 1.12 to 2.04) relative to a general population cohort from the Surveillance, Epidemiology, and End Results Program (SEER). Conclusions: We report histopathologic characteristics of immunocompromised patients developing melanoma at a large academic tertiary-care center. Differences in age, sex, time since transplantation, and transplant type may play a significant role in melanoma SIR in this patient demographic.