Clinical and dermatoscopic fading of post-transplant eruptive melanocytic nevi after suspension of immunosuppressive therapy

Skin cancer in solid organ transplant recipients: still an open problem

In the last two decades, the optimization of organ preservation and surgical techniques, and the personalized immunosuppression have reduced the rate of acute rejections and early post-transplant complications. However, long-term graft survival rates have not improved over time, and evidence suggest a role of chronic calcineurin inhibitor toxicity in this failure. Solid organ transplant recipients may develop chronic dysfunction/damage and several comorbidities, including post-transplant malignancies. Skin cancers, mostly non-melanoma skin cancers (squamous cell carcinoma and basal cell carcinoma), are the most common malignancies in Caucasian solid organ transplant recipients. Several factors, together with immunosuppression, may contribute to the susceptibility for skin cancers which, although often treatable, could be associated with a much higher mortality rate than in the general population. The rapid identification and treatment (including reduction of immunosuppression and early surgical treatments) have an important role to avoid an aggressive behavior of these malignancies. Organ transplant recipients with a history of skin cancer should be followed closely for developing new and metastatic lesions. Additionally, patient education on the daily use of sun-protective measures and the recognition of the early signs (self-diagnosis) of coetaneous malignancies are useful preventive measures. Finally, clinicians should make themselves aware of the problem and build, in every clinical follow-up center, collaborative network involving transplant clinicians, dermatologists and surgeons who should work together to easily identify and rapidly treat these complications. In this review, we discuss the current literature regarding the epidemiology, risk factors, diagnosis, preventive strategies and treatments of skin cancer in organ transplantation.

Skin cancer in children after organ transplantation

Skin cancer is the second most common complication of organ transplantation in children. The frequency of skin cancer incidence after organ transplantation is different in paediatric and adult populations. The post-transplant lymphoproliferative disease is the most common group of malignancies after organ transplantation in paediatric population. The majority of researchers who examined children with kidney, liver, heart or lungs grafts observed that the risk of skin cancer was three times higher than in the general population whereas in adults even200 times higher. The occurrence of skin cancer in children after transplantation is extremely rare during childhood. The risk increases in early adulthood. Malignancies occurring after solid organ transplantation result from many different factors. These include the immunological condition of the child, dose and time of immunosuppression, and oncogenic viruses. The increased risk of skin cancer following paediatric transplantation requires prevention and adequate education of children and their parents. These involve avoiding sun exposure and protection such as sunscreens and protective clothing. The early detection of cancer in transplant recipients is very important. Prevention of cancer includes regular dermatological examination.

Eruptive Melanocytic Nevi: A Review

Eruptive melanocytic nevi (EMN) is a phenomenon characterized by the sudden onset of nevi. Our objective was to compile all published reports of EMN to identify possible precipitating factors and to evaluate the clinical appearance and course. We conducted a systematic bibliographic search and selected 93 articles, representing 179 patients with EMN. The suspected causes were skin and other diseases (50%); immunosuppressive agents, chemotherapy or melanotan (41%); and miscellaneous, including idiopathic (9%). The clinical manifestations could largely be divided into two categories: EMN associated with skin diseases were frequently few in number (fewer than ten nevi), large, and localized to the site of previous skin disease, whereas those due to other causes presented most often with multiple small widespread nevi. In general, EMN seem to persist unchanged after their appearance, but development over several years or fading has also been reported. Overall, 16% of the cases had at least one histologically confirmed dysplastic nevus. Five cases of associated melanoma were reported. We conclude that the clinical appearance of EMN may differ according to the suggested triggering factor. Based on the clinical distinction, we propose a new subclassification of EMN: (1) widespread eruptive nevi (WEN), with numerous small nevi, triggered by, for example, drugs and internal diseases, and (2) Köbner-like eruptive nevi, often with big and few nevi, associated with skin diseases and most often localized at the site of previous skin disease/trauma. The nature of the data precluded assessment of risk of malignant transformation.

Drug-induced eruptive melanocytic nevi

INTRODUCTION

The sudden eruption of melanocytic nevi has been associated with a number of conditions, such as bullous skin diseases, immunodeficiency and immunosuppression. The exact mechanisms leading to the development of eruptive melanocytic nevi are unknown. Areas covered: The aim of this article is to review the literature concerning eruptive melanocytic nevi following the administration of immunosuppressive drugs and other medications. Expert opinion: The literature regarding the development of eruptive nevi in association with pharmacological therapies includes a relatively low number of reports. Prevalence of this phenomenon is likely to be underestimated, thus reporting should be encouraged in order to better define the actual significance and related clinical implications. The development of multiple melanocytic nevi during immunosuppressive treatments highlights the importance of immune system integrity in the regulation of nevi growth. The observation of eruptive nevi as an unexpected effect of targeted therapies for specific types of cancer, including melanoma, provided intriguing hints to understand the mechanisms underlying this paradoxical event. The synergistic role of additional triggers in the occurrence of drug-induced eruptive nevi has not been explored and may be an interesting area of research.

An observational case series on dermatoscopic patterns of fading melanocytic naevi

BACKGROUND/OBJECTIVES

The prevalence of melanocytic naevi falls with age. It has been postulated that this could be due to spontaneous involution (fading). Our objective was to provide dermatoscopic evidence of fading naevi and to describe the patterns of fading observed.

METHODS

Serial dermatoscopic images of naevi demonstrating fading were collected from a set of 25 000 images. Any naevi that showed significant fading, as compared to previous imaging of the same lesion, were included in the analysis.

RESULTS

A total of 47 naevi in 21 patients were found to have significantly faded over a span of 2-11 years. The dermatoscopic fading was observed to occur in two patterns. The most common pattern observed was generalised fading (n = 45), where fading was present over all the naevus. There were two cases of focal fading (n = 2) where fading was present only over one area of the naevus.

CONCLUSIONS

Fading melanocytic naevi are uncommon. Melanocytic naevi fade in recognisable patterns, with generalised fading most commonly observed in our series.

Cutaneous malignant melanoma in the Swedish organ transplantation cohort: A study of clinicopathological characteristics and mortality

BACKGROUND

Risk of cutaneous melanoma is increased among organ transplant recipients (OTRs) but outcome has rarely been evaluated.

OBJECTIVE

We sought to assess melanoma characteristics and prognosis among OTRs versus the general population.

METHODS

Using Swedish health care registers, we identified melanomas in OTRs (n = 49) and in the general population (n = 22,496), given a diagnosis between 1984 and 2008 and followed up through December 31, 2012. Tumor slides of posttransplantation melanomas were reviewed. Odds ratios for comparison of histopathological characteristics and hazard ratios of melanoma-specific death were calculated.

RESULTS

Among OTRs the trunk was the most common anatomic melanoma site (50% among female vs 51% among male) and 73% (n = 36) of all melanomas were histologically associated with a melanocytic nevus, 63% (n = 31) atypical/dysplastic. Compared with population melanomas, posttransplantation melanomas were more advanced at diagnosis (Clark level III-V: odds ratio 2.2 [95% confidence interval 1.01-4.7, P = .03], clinical stages III-IV: odds ratio 4.2 [1.6-10.8, P = .003]). Risk of melanoma-specific death was increased among OTRs: adjusted hazard ratio 3.0 (1.7-5.3, P = .0002).

LIMITATIONS

Only posttransplantation melanoma slides were reviewed.

CONCLUSIONS

Melanomas were more advanced at diagnosis and melanoma-specific survival was poorer in OTRs than in the general population. Prophylactic excision of truncal nevi among OTRs may be advised.

[Childhood eruptive nevi: a case report]

"Eruptive nevi" is a phenomenon characterized by a rapid appearance of multiple melanocytic nevi. It is mainly developed in three groups of patients: those with systemic immunosuppression, bullous cutaneous disorders, and a melanocytic stimulation drug. We report on the case of an 11-year-old boy who was diagnosed with acute lymphoblastic leukemia. A few months after the beginning of the chemotherapy, he developed multiple pigmented lesions over the skin. Eruptive nevi syndrome has been described in the literature in 29 cases in the context of severe bullous disease and in immunosuppression. Nevi most often appear on the trunk and extremities, notably on the feet in the context of immunosuppression. They are localized in areas of bullous lesions in bullous diseases. Due to an increased melanocytic stimulation in eruptive nevi patients, long-term surveillance of individuals who have developed eruptive nevi is required, and increased sun prevention should be suggested.

Melanoma in immunosuppressed patients

The immunogenic characteristics of malignant melanoma are intriguing. To date, multiple studies exist regarding the immunogenicity of melanoma. In this article, we summarize data in the literature on the role of immunosuppression in melanoma and discuss several immunocompromised patient populations in detail. A comprehensive PubMed search was conducted with no date limitation. The following search terms were used: melanoma in combination with immunosuppression, immunocompromised, genetics, antigen processing, UV radiation, organ transplantation, organ transplant recipients, lymphoproliferative disease, lymphoma, CLL, NHL, radiation, and HIV/AIDS. Although no formal criteria were used for inclusion of studies, most pertinent studies on the topic were reviewed, with the exception of smaller case reports and case series. The included studies were generally large (≥ 1000 patients in organ transplant recipient studies; ≥ 500 patients in lymphoma studies), with a focus on institutional experiences, or population-based national or international epidemiologic studies. Melanoma-induced immunosuppression, the role of UV radiation in melanoma development, and the epidemiology, clinical course, and prognosis of melanoma in immunocompromised patients are highlighted. Organ transplant recipients, patients with lymphoproliferative disorders, patients with iatrogenic immunosuppression, and patients with human immunodeficiency virus infection/AIDS are also highlighted. Recommendations are proposed for the care and monitoring of immunosuppressed patients with melanoma. With better understanding of the molecular microenvironment and clinical course of melanoma in immunosuppressed patients, novel therapies could be developed and outcomes potentially affected in these patients.

A case with postchemotherapy eruptive compound nevus

An 8-year-old male patient who had been diagnosed as acute lymphoblastic leukemia (ALL) 4 years ago and received 120 cures of chemotherapy presented at our clinic complaining of spots on his body 3 months after the end of chemotherapy. Anamnesis of the patient revealed that the lesions started 3 months after the last cure of chemotherapy on the abdomen and spread throughout the body. It was learnt that the number of spots increased very rapidly in a period of 2 months, and exceeded 100. A dermatological examination of the patient showed 142 hyperpigmented macules, the largest of which was 1 cm × 1 cm and the smallest was 0.2 cm × 0.2 cm in size, diffusely scattered to the skin and oral mucosa. When the biopsy material taken from the lesions was histopathologically examined, nest structures composed of nevus cells with oval nuclei and eosinophilic cytoplasm starting from the dermoepidermal junction and extending toward the lower epidermis were observed and found to be consistent with the compound nevus. We present this rare case who was diagnosed as “eruptive compound nevus” on the basis of clinical signs, ALL diagnosis, chemotherapy history and histopathologic evaluation.

Activating BRAF mutations in eruptive melanocytic naevi

BACKGROUND

Eruptive melanocytic naevi (EMN) are melanocytic proliferations developing rapidly on previously unaffected skin in association with various clinical scenarios, most commonly systemic immunosuppression. However, the exact mechanism leading to development of EMN is not understood. In particular, it is not known whether EMN harbour the BRAF mutations which occur frequently in melanoma and most common naevi.

OBJECTIVES

To evaluate whether activating BRAF mutations may play a role in genesis of EMN.

METHODS

Genomic DNA was isolated from 20 EMN from a patient treated with 6-mercaptopurine (6-MP). Primary BRAF genotyping was performed by allelespecific polymerase chain reaction, followed by validation using direct sequencing.

RESULTS

The BRAF V600E mutation was identified in 85% of EMN examined.

CONCLUSIONS

Our results implicate mutational activation of the BRAF–MAPK pathway as a factor in development of EMN in the setting of 6-MP treatment. The mechanism leading to development of EMN in this, and potentially other patients, may relate to synergistic mutagenic effects of thioguanines and ultraviolet (UV) A. Together with the documented importance of BRAF mutations in melanoma development and maintenance, these findings highlight the importance of UVA protection, especially in patients treated with thiopurines such as 6-MP.

Effect of reduced immunosuppression after kidney transplant failure on risk of cancer: population based retrospective cohort study

OBJECTIVE

To compare cancer incidence in kidney transplant recipients during periods of transplant function (and immunosuppression) and after transplant failure (when immunosuppression is ceased or reduced). Design, setting, and participants Nationwide, population based retrospective cohort study of 8173 Australian kidney transplant recipients registered on the Australia and New Zealand Dialysis and Transplant Registry who first received a transplant during 1982-2003. Incident cancers were ascertained using linkage with national cancer registry records.

MAIN OUTCOME MEASURES

Cancer-specific standardised incidence ratios for periods of transplant function and for dialysis after transplant failure. Incidence was compared between periods using multivariate incidence rate ratios adjusted for current age, sex, and duration of transplantation.

RESULTS

All cases of Kaposi's sarcoma occurred during transplant function. Standardised incidence ratios were significantly elevated during transplant function, but not during dialysis after transplant failure, for non-Hodgkin's lymphoma, lip cancer, and melanoma. For each of these cancers, incidence was significantly lower during dialysis after transplant failure in multivariate analysis (incidence rate ratios 0.20 (95% CI 0.06 to 0.65) for non-Hodgkin's lymphoma, 0.04 (0.01 to 0.31) for lip cancer, and 0.16 (0.04 to 0.64) for melanoma). In contrast, standardised incidence ratios during dialysis after transplant failure remained significantly elevated for leukaemia and lung cancer, and cancers related to end stage kidney disease (kidney, urinary tract, and thyroid cancers), with thyroid cancer incidence significantly higher during dialysis after transplant failure (incidence rate ratio 6.77 (2.64 to 17.39)). There was no significant difference in incidence by transplant function for other cancers.

CONCLUSIONS

The effect of immunosuppression on cancer risk is rapidly reversible for some, but not all, cancer types. Risk reversal was mainly observed for cancers with a confirmed infectious cause. Risk of other cancers, especially those related to end stage kidney disease, remained significantly increased after reduction of immunosuppression.

Immunosuppression and melanocyte proliferation

Melanocytes are pigmented cells derived from the neural crest; their proliferation is restrained by immune system. The eruption of nevi after an immunosuppressive condition is a peculiar phenomenon indicating that the immune system may play a major role in limiting proliferation of melanocytes. In this review, we analyze the role of immunosuppressive regimens on melanocyte proliferation. In particular, we discuss the eruptive nevi phenomenon, which is determined by the inability of the immune system to inhibit melanocyte proliferation. These clinical observations indicate that the immune system has a pivotal role in restraining melanocyte proliferation. However, although the role of the immune system in the development of nonmelanoma skin cancer has been shown clearly in several studies involving organ transplant patients, the role of immunosuppression in melanoma genesis has not yet been established. Further investigations are required to establish the real immunogenicity of melanoma, particularly in the light of the dichotomy between the eruptive nevi phenomenon in immunosuppressed patients and the low incidence of melanoma in transplanted patients.