Clinicopathological features, MCPyV status and outcomes of Merkel cell carcinoma in solid-organ transplant recipients: a retrospective, multicentre cohort study.

BACKGROUND: The proportion of Merkel cell carcinomas (MCCs) in solid-organ transplant recipients (SOTR) harbouring Merkel cell polyomavirus (MCPyV) is unknown, as are factors affecting their outcomes. OBJECTIVE: To describe clinicopathological features of MCC in SOTR, investigate the tumoral MCPyV-status and identify factors associated with tumour outcomes. METHODS: Retrospective, international, cohort-study. MCPyV-status was investigated by immunohistochemistry and polymerase chain reaction. RESULTS: A total of 30 SOTR and 44 consecutive immunocompetent patients with MCC were enrolled. SOTR were younger at diagnosis (69 vs. 78 years, P < 0.001). Thirty-three percent of SOTR MCCs were MCPyV-positive vs. 91% of immunocompetent MCCs (P = 0.001). Solid-organ transplantation was associated with an increased cumulative incidence of progression (SHR: 3.35 [1.57-7.14], P = 0.002), MCC-specific mortality (SHR: 2.55 [1.07-6.06], P = 0.034) and overall mortality (HR: 3.26 [1.54-6.9], P = 0.002). MCPyV-positivity and switching to an mTOR inhibitor (mTORi) after MCC diagnosis were associated with an increased incidence of progression (SHR: 4.3 [1.5-13], P = 0.008 and SHR: 3.6 [1.1-12], P = 0.032 respectively) in SOTR. LIMITATIONS: Retrospective design and heterogeneity of SOTR cohort. CONCLUSIONS: MCPyV appears to play a less prominent role in the aetiopathogenesis of MCC in SOTR. SOTR have a worse prognosis than their immunocompetent counterparts and switching to an mTORi after the diagnosis of MCC does not improve progression.

Clinical aspects of epidermodysplasia verruciformis.

Thirteen patients with epidermodysplasia verruciformis (EV) were studied over a period of 7 years. EV is a rare genodermatosis characterized by a generalized infection with a specific group of human papilloma virus (HPV) and a propensity for developing skin malignant tumours in 30%-50% of patients. The diagnosis of EV was confirmed by histopathological and immunohistochemical findings. Three of our patients had the benign form of EV, which is characterized by monomorphous lesions and no malignant changes, whereas 10 had the malignant form, which is characterized by polymorphic lesions and development of cutaneous malignant tumours. All EV patients with the malignant form developed multiple skin tumours (77%). They started to appear at age 20, predominantly on the forehead (50%). Most were squamous cell carcinoma, extremely aggressive and invasive, which provoked metastasis and death in two patients.