Merkel cell carcinoma in organ-transplant recipients: report of two cases with unusual histological features and literature review

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.

Demographics and outcomes of stage I and II Merkel cell carcinoma treated with Mohs micrographic surgery compared with wide local excision in the National Cancer Database

BACKGROUND

The optimal surgical approach (wide local excision [WLE] vs Mohs micrographic surgery [MMS]) for treating Merkel cell carcinoma (MCC) is yet to be determined.

OBJECTIVE

To compare survival outcomes in patients with early-stage MCC treated with MMS versus with WLE.

METHODS

A retrospective review of all cases in the National Cancer Database (NCDB) of MCC of clinical stage I or II MCC treated with WLE or MMS was performed.

RESULTS

A total of 1795 cases of stage I or II MCC who underwent WLE (n = 1685) or MMS (n = 110) were identified. There was no difference in residual tumor on surgical margins between the 2 treatment groups (P = .588). On multivariate analysis, there was no difference in overall survival between the treatment modalities (adjusted hazard ratio, 1.02; 95% confidence interval, 0.72-1.45; P = .897). There was no difference in overall survival between the 2 groups on propensity score-matched analysis.

LIMITATIONS

Disease-specific survival was not reported, as these data are not available in the National Cancer Database.

CONCLUSIONS

MMS appears to be as effective as WLE in treating early-stage MCC.

Comparison of the incidence of skin cancers in patients on dialysis and after kidney transplantation

INTRODUCTION

Kidney transplant (KTx) patients on immunosuppressive therapy are predisposed to the development of infections and cancers.

AIM

To compare the incidence and type of malignant skin lesions in kidney transplant patients and the dialyzed population based on the initiated dermatologic screening.

MATERIAL AND METHODS

The study included 598 patients: 486 kidney transplant recipients and 112 patients on maintenance dialysis. All the patients underwent dermatological examination. Only histologically confirmed cancers were included in this study. Age, gender and immunosuppressive therapy administration were also considered. Patients were followed up by a dermatologist for a period of 5 years.

RESULTS

Fifty-eight skin cancers; 39 basal cell carcinomas (BCC), 13 squamous cell carcinomas (SCC), 1 Bowen disease, 2 Kaposi sarcoma, 1 malignant melanoma, 1 Merkel cell carcinoma, and 1 fibrosarcoma protuberans were diagnosed in 30 (6.2%) kidney transplant patients, and 8 lesions (7 BCC and 1 SCC) were found in 4 (3.6%) patients on dialysis.

CONCLUSIONS

The initiated dermatologic screening program indicates that the risk of skin cancer incidence in post kidney transplant patients receiving immunosuppressive therapy was significantly higher than in patients on dialysis.

Merkel Cell Carcinoma of the Hand: A Case Report and Review of the Literature

Background: Merkel cell carcinoma (MCC) is a relatively rare and aggressive cutaneous neuroendocrine malignancy characterized by high incidence of local recurrence, distant metastases, regional nodal metastases, and high mortality. Clinically, MCC presents as a persistent asymptomatic red/pink shaped nodule, usually smaller than 2 cm with nontender intracutaneous swelling, with rapidly growing localized disease with lymph node metastases preceding distant metastases. Because of its rare nature and the lack of comprehensive understanding of the disease, management of MCC has been controversial. Methods: An 87-year-old retired Caucasian male with a history of tobacco use, chronic sun exposure, and multiple squamous and basal cell carcinomas presented with a 1.8 × 1.3 cm red, nontender nodule on the dorsum of the proximal phalanx of the left long finger first noticed 6 months prior to presentation. Biopsy was consistent with MCC after which he was treated with wide local excision, full-thickness skin grafting, and sentinel lymphadenectomy (1/4 nodes positive) followed by adjuvant radiation therapy. Results: He recovered appropriately and was clinically and radiographically disease free at 2.5-year follow-up. Conclusion: Although it remains rare, MCC has increased in incidence over the last several decades and has a predilection to occur over sun exposed areas. Highly aggressive, it has a high incidence of regional and distant metastasis as well as local recurrence. As a result, it is important that practitioners involved in the care of skin and hand lesions be aware of this condition and the need for a multidisciplinary treatment approach.

Skin cancer in organ transplant recipients

Organ transplant recipients (OTR) are at a significantly increased risk for developing a wide variety of skin cancers, particularly epithelial skin cancer, Merkel cell carcinoma and Kaposi's sarcoma. Melanoma, skin adnexal neoplasm and cutaneous lymphomas are also more common in OTR and may differ in their clinicopathologic presentation from tumors in immunocompetent patients. The accuracy of clinical diagnosis of suspected premalignant and malignant skin lesions in OTR is modest. Therefore, histopathological diagnosis is an essential element for the diagnostic workup of skin cancers and, in addition, provides important information on prognosis. Squamous cell carcinoma and intraepithelial neoplasias (actinic keratosis, squamous cell carcinoma in situ or Bowen's disease) are the most common forms of skin cancer in OTR. The risk of Merkel cell carcinoma and Kaposi's sarcoma is dramatically increased in OTR. Merkel cell carcinoma shows a highly aggressive course. Kaposi's sarcoma tends to spread to extracutaneous sites. Primary cutaneous lymphomas developing after organ transplantation are rare. The spectrum of cutaneous B cell lymphomas in OTR, in particular, differs significantly from that of the general population, with a predominance of Epstein-Barr virus-driven posttransplant lymphoproliferative disorder. This review discusses the clinical and histopathological aspects of skin cancers in OTR, the impact of dermatopathological analysis on prognosis and the understanding of the pathogenesis of these neoplasms.

Detection of a novel truncating Merkel cell polyomavirus large T antigen deletion in chronic lymphocytic leukemia cells

Merkel cell polyomavirus (MCPyV) is detected in approximately 80% of Merkel cell carcinomas (MCC). Yet, clonal integration and truncating mutations of the large T antigen (LTAg) of MCPyV are restricted to MCC. We tested the presence and mutations of MCPyV in highly purified leukemic cells of 70 chronic lymphocytic leukemia (CLL) patients. MCPyV was detected in 27.1% (n = 19) of these CLL cases. In contrast, MCPyV was detected only in 13.4% of normal controls (P < .036) in which no LTAg mutations were found. Mutational analyses revealed a novel 246bp LTAg deletion in the helicase gene in 6 of 19 MCPyV-positive CLL cases. 2 CLL cases showed concomitant mutated and wild-type MCPyV. Immunohistochemistry revealed protein expression of the LTAg in MCPyV-positive CLL cases. The detection of MCPyV, including LTAg deletions and LTAg expression in CLL cells argues for a potential role of MCPyV in a significant subset of CLL cases.

Organ transplantation and skin cancer: basic problems and new perspectives

Solid organ transplant and subsequent graft survival have increased worldwide, while immunosuppression has prevented rejection with increasing success. Side effects of cutaneous infection and neoplasm, however, affect the majority of solid organ transplant recipients (OTRs). Squamous cell carcinoma of the skin (SCC) is the most common neoplasm overall following organ transplant with a risk that is 60-100 times greater than for the immunocompetent population. This review focuses on questions of ongoing debate about SCC formation in OTRs such as viral carcinogenesis, systemic photoprotection, photosensitization by drugs, the impact of immunosuppressive drugs and inflammation as a driver of carcinogenesis.

Merkel cell carcinoma demographics, morphology, and survival based on 3870 cases: a population based study

BACKGROUND

Merkel cell carcinoma (MCC) is a rare and aggressive neuroendocrine tumor arising predominantly on sun-exposed skin of older and usually immunosuppressed individuals.

METHODS

Using data from NCI's SEER (Surveillance, Epidemiology, and End Results) Program from 1973 to 2006, we analyzed the demographics and survival of MCC.

RESULTS

SEER had recorded 3870 cases of MCC. The incidence was higher in men (2380 cases, 61.5%) than in women (1490 cases, 38.5%). Most patients were White (94.9%) between 60 and 85 years of age. MCC was rare in Blacks. The most common location was the head and neck. The salivary glands, nasal cavity, lip, lymph nodes, vulva, vagina and esophagus were the most common extracutaneous sites. The 10-year relative survival rate was higher in women than men (64.8% vs. 50.5%, p < 0.001). Patients 50-69 years had the highest 10-year relative survival rate (59.6%). Stage of disease was the best predictor of survival.

CONCLUSIONS

MCC arises predominantly in the skin of head and neck in White men above 70 years of age. Cases also occurred in extracutaneous sites. Age did not predict survival, yet gender, site and tumor size revealed clear differences. The most significant predictor of survival was tumor stage.

Merkel cell polyomavirus sequences are frequently detected in nonmelanoma skin cancer of immunosuppressed patients

Recently, a new human polyoma virus has been identified in Merkel cell carcinomas (MCC). MCC is a highly aggressive neuroendocrine nonmelanoma skin cancer (NMSC) associated with immunosuppression. Clonal integration of this virus which was termed Merkel cell polyoma virus (MCPyV) was reported in a number of MCC. Squamous cell carcinoma (SCC) and basal cell carcinoma (BCC) are also NMSC and are the most frequent cancers in the setting of immunosuppression. A unique group of 56 NMSC from 11 immunosuppressed patients and 147 NMSC of 125 immunocompetent patients was tested for MCPyV by DNA PCR, targeting the Large T Antigen and the structural Viral Protein 1. NMSC included SCC, BCC and Bowen's disease (BD). In addition, normal skin and 89 colorectal cancers were tested. MCPyV specific sequences were significantly more frequently found in NMSC of immunosuppressed patients compared to immunocompetent patients (p < 0.001). In particular BD and BCC revealed a significant increased association of MCPyV of immunosuppressed patients (p = 0.002 and p = 0.006). Forty-seven of 147 (32%) sporadic NMSC were MCPyV positive. Interestingly, 37.5% (36/96) of sporadic BCC of immunocompetent patients were MCPyV positive. No MCPyV was detected within normal skin and only 3 out of 89 of additionally tested colorectal cancers were MCPyV positive. Our data show that MCPyV is a frequently reactivated virus in immunocompromized patients. How MCPyV contributes to the pathogenesis of NMSC, i.e., BD, SCC and BCC, in immunosuppressed patients and in addition, potentially to the pathogenesis of a subset of sporadic BCC needs further investigations.

Collision tumor composed of Merkel cell carcinoma and lentigo maligna melanoma

We report the case of an immunocompetent 79-year-old white man with a history of melanoma in situ on the back with a collision tumor composed of a Merkel cell carcinoma (MCC) and lentigo maligna melanoma on the left cheek. The cells of the MCC expressed cytokeratin 20 (CK 20) in a diffuse cytoplasmic pattern, AE1 and AE3 in a perinuclear dot-like pattern and diffusely with neuron-specific enolase. The tumor cells of the MCC failed to express thyroid transcription factor-1. The atypical melanocytes of lentigo maligna melanoma expressed Melan-A and S-100. At the same visit, a lentigo maligna was diagnosed by excisional biopsy on the right cheek. The variability in expression of CK 20, AE1 and AE3 in MCC are reviewed. Prior reports of MCC in collision with non-melanoma skin cancers are reviewed. Additionally, the role of immunosuppression in the development of MCC is considered.

A comprehensive review of the treatment of Merkel cell carcinoma

Merkel cell carcinoma (MCC) is an uncommon but malignant cutaneous neuroendocrine carcinoma with a high incidence of local recurrence, regional lymph node metastases, and subsequent distant metastases. The etiology of MCC remains unknown. It usually occurs in sun-exposed areas in elderly people, many of whom have a history of other synchronous or metachronous sun-associated skin lesions. The outcome for most patients with MCC is generally poor. Surgery is the mainstay of treatment. The role of adjuvant therapy has been debated. However, data from recent development support a multimodality approach, including surgical excision of primary tumor with adequate margins and sentinel lymph node dissection followed by postoperative radiotherapy in most cases, as current choice of practice with better locoregional control and disease-free survival. Patients with regional nodal involvement or advanced disease should undergo nodal dissection followed by adjuvant radiotherapy and, perhaps, systemic platinum-based chemotherapy in most cases.

An unusual case of Merkel cell carcinoma

PURPOSE

Merkel cell carcinoma (MCC) is a rare aggressive neuroendocrine tumor of the skin mainly found in elderly white patients. Due to its poor prognosis with distant metastases in up to 33% and local recurrence in 25-33% and a 5 year disease-specific survival of 64% (1-2) its early diagnosis and appropriate treatment is mandatory.

METHODS

The study is an exceptional clinical case of a patient with a large inoperable MCC unable to be treated according to treatment guidelines due to her old age. We review the literature addressing treatment options.

RESULTS

The patient was treated with palliative definitive radiotherapy to her large MCC of the left lower leg. She showed a rapid clinical response to four palliative radiation doses of 7 Gy each, necrosis of tumor mass and persistent clearing at a follow-up of 32 weeks. Our patient was very unusual in terms of her extensive MCC and her rapid and complete response to palliative radiotherapy lasting for 6 months at present.

CONCLUSIONS

As MCC is an aggressive tumor, best survival is achieved with early diagnosis in a localized stage and prompt adequate surgery and further stage-adjusted treatment. Thus, the differential diagnosis of MCC should not be dismissed in a reddish nodule on the leg, and every excision should be submitted to pathology. In accordance with the literature we demonstrate here that definitive radiotherapy is an effective treatment option for inoperable MCC, which in this individual patient produced necrosis of the extensive tumor mass after only four palliative doses.

Merkel cells

Merkel cells are post-mitotic cells scattered throughout the epidermis of vertebrates. They are particularly interesting because of the close connections that they develop with sensory nerve endings and the number of peptides they can secrete. These features suggest that they may make an important contribution to skin homeostasis and cutaneous nerve development. However, these cells remain mysterious because they are difficult to study. They have not been successfully cultured and cannot be isolated, severely hampering molecular biology and functional analysis. Merkel cells probably originate in the neural crest of avians and mammalians, and their "spontaneous" appearance in the epidermis may be caused by a neuron-independent epidermal differentiation process. Their functions are still unclear: they take part in mechanoreception or at least interact with neurons, but little is known about their interactions with other epidermal cells. This review provides a new look at these least-known cells of the skin. The numerous peptides they synthesize and release may allow them to communicate with many cells other than neurons, and it is plausible that Merkel cells play a key role in skin physiology and physiopathology.