Cutaneous undifferentiated small (Merkel) cell carcinoma, that developed synchronously with multiple actinic keratoses, squamous cell carcinomas and basal cell carcinoma.

Merkel cell carcinoma (MCC) has recently been associated with a novel polyomavirus. This rare but highly aggressive skin malignancy has been increasing in incidence over the past two decades.1 It is most common in elderly Caucasians as well as immunocompromised patients. Feng et al.2 was the first to discover that the Merkel cell polyomavirus (MCPyV) was integrated within the tumor genome, suggesting that it may be a contributing factor in the pathogenesis of MCC. Since then other studies have confirmed that approximately 80% of MCC are associated with MCPyV.3–7 Further studies have demonstrated that MCPyV is clonally integrated at various sites in the genome of MCC tumors, with truncating mutations that interrupt viral replication; therefore, demonstrating that the virus is not a passenger virus that secondarily infects MCC tumors, but is an etiological agent.8,9 This recent discovery has since sparked controversy, as there have been conflicting reports of the virus contributing to other skin cancers. Recent studies have shown a high prevalence of MCPyV DNA in MCC, supporting a role for the virus in tumorigenesis; however, a high prevalence of the virus has also been identified in non-melanoma skin cancers as well as non-lesional skin.10–13 One hypothesis suggests that the polyomavirus is ubiquitous, and when the virus is detected in basal cell carcinoma (BCC) or squamous cell carcinoma (SCC), it represents a coincidental infection rather than an etiological agent. Detection of MCPyV DNA polymerase chain reaction (PCR) positivity in BCC and SCC tumors is likely to represent loss of immune control over viral replication leading to enhanced coincidental detection. Because detecting viral DNA by qualitative PCR cannot differentiate incidental infection from causal infections, more studies are needed to demonstrate active viral protein expression of MCPyV small T antigen. Using a monoclonal antibody to detect MCPyV large T antigen, Reisinger et al.14 demonstrated MCPyV protein expression in 75% of MCC tumors but detected no large T antigen positivity in BCC or SCC from the same patients. In our case, we were able to test several lesions for the presence of MCPyV using both qualitative and quantitative PCR. A 73-year old Caucasian male presented to the skin cancer clinic for a full skin examination. He had a history of multiple actinic keratoses treated with cryotherapy but no history of skin cancer. His past medical history was significant for ulcerative colitis, currently treated with prednisone, mercaptopurine, and mesalamine, coronary artery disease status post bypass grafting, gastroesophageal reflux, deep vein thrombosis following a knee replacement, and osteoarthritis. The patient complained of a recurrent lesion on his left mid-cheek that had been previously treated with cryotherapy. Physical examination revealed Fitzpatrick skin type I with marked dermatoheliosis on sun-exposed areas as well as a 3 mm hyperkeratotic pink papule within a scar on the left mid-cheek and a 12 × 8-mm irregular dark brown patch on the inferior left mid-cheek. Skin biopsies were performed on the two facial lesions, revealing nodular BCC of the left mid-cheek and melanoma in situ of the inferior left mid-cheek, respectively. The lesions were removed with elliptical excision and intermediate linear layered closure four days after the initial visit. Two months after the patient’s skin examination, he developed a new, tender red nodule on his posterior right arm, which did not respond to antibiotic therapy and local heat application. His primary care physician removed the nodule by elliptical excision. The pathology report revealed a 2.2-cm MCC with focal necrosis and positive margins with evidence of vascular invasion. Immunohistochemical studies demonstrated the tumor cells were positive for pankeratin, CK20, chromogranin, and synaptophysin, and negative for LCA, HMB-45, keratin-7, and TTF-1. Due to his new diagnosis of MCC, he returned to the skin cancer clinic. At that time, he had a new pink papule on his nose, which was biopsied and found to be a BCC. There was also a new hyperkeratotic papule on his left antitragus, which was biopsied and found to be an actinic keratosis. He underwent a wide local excision of the MCC and an axillary lymph node dissection, which revealed 1/27 positive lymph nodes. Basic blood work was performed, which showed no evidence of hematological malignancy. A human immunodeficiency virus (HIV) test was negative. Chest x-ray showed stable pulmonary fibrosis with no evidence of metastases. He was started on radiation therapy and is scheduled to receive adjuvant chemotherapy with four cycles of cisplatin and etoposide. All tissue specimens obtained from the patient were tested for the presence of MCPyV DNA. DNA quality assessment was first performed using a beta-globin reference gene PCR of the DNA extracted from the samples. MCPyV detection was performed with PCR utilizing a primer set designed in our lab within the “small T” region of the virus. In four samples, putative MCPyV-PCR products were detected. The MCC, two samples of the Merkel cell-positive lymph node, and the actinic keratosis tested positive for MCPyV DNA. The melanoma in situ and the two BCC were negative for the polyomavirus (Fig. 1). MCPyV copy number determination with real-time PCR technology, designed within the “small T” viral region, was then performed on the samples found positive by the qualitative PCR. MCPyV copy number/nanogram tissue DNA was highest in the primary MCC (769) compared with the two metastatic lymph node samples (20, 81). MCPyV copy number was very low in the actinic keratosis (0.15) compared with the samples from the primary MCC and lymph node metastases. Detection of MCPyV DNA by PCR in different lesions from a patient with MCC. PCR products were analyzed on 2.0% agarose gel electrophoresis and visualized on a UV transilluminator. Lanes, M: φX174RF DNA marker (Promega); 1: BCC; 2: actinic keratosis; 3: primary MCC; 4–6: melanoma in situ and adjacent skin edges; 7 and 8: sentinel lymph nodes with MCC metastases; C+: MCPyV positive control (plasmid with MCPyV DNA insert from the small T viral); C−: MCPyVC negative control DNA extracted from PBMC (Promega); R: reagent control. 150-bp MCPyV PCR products can be seen in lanes 2, 3, 7 and 8, as well as in the positive control Our case further confirms the association of MCPyV and MCC. The virus was detected in the MCC and MCC-positive lymph node but was not detected in the melanoma in situ or the two BCC. Our case, however, also demonstrates the complexity and controversial nature of the issue as the virus was also detected in the actinic keratosis. The copy number determination demonstrated a very low number in the actinic keratosis as compared with the MCC and positive lymph node. This strengthens the hypothesis that the polyomavirus did not have an etiological role in the actinic keratosis but that the lesion was likely coincidentally infected by the ubiquitous virus. There are abundant data providing evidence of an association between MCC and immunosuppression. Patients with HIV have a relative risk of MCC of 13.4 compared with the general population.15 An increased rate of other malignancies in patients with MCC further supports an impaired immune status in the pathogenesis of MCC. An increased risk of MCC as a second primary has been identified in patients with multiple myeloma, chronic lymphocytic leukemia, non-Hodgkin’s lymphoma SCC, and melanoma.16,17 Recognizing this association of MCC with other malignancies may lead to earlier detection of MCC and therefore earlier treatment and improved survival. Our case is also consistent with the fact that immunosuppression is a risk factor for MCC. Although the workup for HIV and hematological malignancies was negative, our patient was iatrogenically immunosuppressed as he had been on 10 mg of prednisone daily for the past four years for ulcerative colitis. While most studies have shown an association with patients receiving post-transplantation immunosuppression or chemotherapy, it may be possible that our patient’s four-year history of prednisone therapy was sufficient enough to contribute to the pathogenesis of his MCC.18–20 The newly discovered virus appears to be widespread, so it is unclear why it only causes MCC in very few people. Other factors such as ultraviolet radiation, immunogenetics, and immunosuppression likely also contribute to carcinogenesis. More studies are needed to determine viral oncoprotein expression to further delineate the ubiquitous virus’ role in MCC tumorigenesis from a possible passenger virus in non-lesional skin and non-melanoma skin cancer. Although the role of this polyomavirus is controversial, the discovery of the virus in association with MCC will hopefully lead to more effective therapy for the highly aggressive tumor.

The main objective of this paper is to establish the predictive value of a dynamic assessment (DA) device on the school performance and progress achieved by a group of subjects with special learning difficulties. We also analyse to what extent the results obtained offer additional information to the one provided by static assessment tests on reading comprehension, personal-social adjustment or cognitive performance. With this aim, we used two external criteria: (a) the assessment of academic performance and progress, and (b) the subjects’ marks in the area of Language. The participating teachers had to evaluate each of the seven proposed assessment criteria using a four-level qualitative scale. In addition, they had to assess whether, for each of those criteria, the subject had made some progress or not during the experimental phase. The sample consisted of 60 subjects (experimental group) with learning disabilities (LD), on whom the DA device was implemented, and 73 subjects (control group) also having LD. The dynamics scores obtained from the application of the EDPL device (dynamic assessment of processes involved in reading tasks) indicated predictive values on school performance and progress that were significantly higher than those shown by various static evaluation approaches to reading and the evaluation of the IQ.

Merkel cell carcinoma in a patient with noninvasive vulvar Paget's disease

BackgroundMerkel cell carcinoma (MCC) is an increasingly common neuroendocrine cancer of the skin. Merkel cell polyomavirus (MCPyV) is one of the causative agents of MCC. The prevalence of MCPyV in primary MCC and sun-exposed non-MCC tumors has been known to have different results depending on where it was investigated.ObjectiveThis study assesses the prevalence of MCPyV from primary MCC and sun-exposed non-MCC tumors in Korea.MethodsA molecular pathology study was performed on 7 tissue specimens of MCC, 1 tissue specimen of metastatic small cell carcinoma of the lung, and 32 tissue specimens of non-MCC tumors occurring from sun-exposed areas [8 basal cell carcinomas (BCCs), 8 squamous cell carcinomas (SCCs), 8 actinic keratoses (AKs), and 8 seborrheic keratoses (SKs)]. All specimens were analyzed to determine the presence of MCPyV-DNA using both polymerase chain reaction (PCR) and real-time quantitative PCR. Immunohistochemistry with monoclonal antibody of MCPyV large T antigen (CM2B4) was also conducted.ResultsUsing both PCR, MCPyV sequences were detected in six of seven MCC tissue specimens (85.7%). Five (71%) of seven MCC tumors were immunoreactive for CM2B4. All five immunoreactive cases were positive for MCPyV. However, there was no association of MCPyV with BCC, SCC, AK, and SK.ConclusionOur results implicate that MCPyV may contribute to the pathogenesis of primary MCC, not of non-MCC skin tumors in Korea, and the persons with MCPyV infection are unusual in Korea compared to other areas.

Maria Sternemann Thomas Wiegel Christoph C. Geilen Constantin E. Orfanos Wolfgang Hinkelbein Basel S. Karger Controversies in the Treatment of Skin Neoplasias 2006 180 pp. $162 hardcover ISBN: 3-8055-8014-2.

Cytokeratin 20 (CK20) is a low-molecular-weight cytokeratin (CK) that shows restricted expression in the gastrointestinal epithelium, urothelium, and Merkel cell. Recent studies have suggested that since Merkel cell (primary cutaneous neuroendocrine) carcinomas are consistently CK20-positive, this feature may help to distinguish it from pulmonary small cell carcinomas. However, only limited numbers of these tumors have been studied, and the pattern of CK20 expression in other small cell carcinomas has not been established. Therefore, we studied CK20 expression in small cell carcinomas from a wide variety of sites. Immunohistochemical study was performed on paraffin sections using CK20 antibody, coupled with antigen retrieval by pressure cooking in citrate buffer. The cases included 34 Merkel cell carcinomas and 89 small cell carcinomas from various sites (pulmonary, 37; gastrointestinal tract, nine; pharynx and tongue, two; sinonasal tract, three; salivary gland, five; larynx, nine; breast, two; thymus, three; uterine cervix and corpus, 12, prostate, three; urinary bladder, two; kidney, one; pancreas, one). In addition, all cases were immunostained with pan-CK (MNF-116) and low-molecular-weight CK (CAM5.2) antibodies to ascertain their epithelial nature. With the exception of one case, all Merkel cell carcinomas were CK20-positive; and 30 of the 33 cases showed a punctate pattern. Almost 100% of tumor cells were positive, except for two cases that showed staining of 10% and 30% of tumor cells, respectively. Among the other small cell carcinomas, only five cases were CK20-positive, including one of 37 pulmonary (40% cells positive in punctate pattern), one of 11 cervical (10% cells positive), and three of five salivary gland (100% cells positive). We conclude that CK20-positivity in a small cell carcinoma of uncertain origin strongly predicts a diagnosis of Merkel cell carcinoma, especially if the majority of tumor cells are positive. A negative CK20 reaction can practically rule out Merkel cell carcinoma, provided that an effective antigen retrieval technique is used and appropriate staining is obtained with other cytokeratin antibodies. The frequent CK20 positivity observed in salivary gland small cell carcinomas in this series suggests that at least some of them may be more closely related biologically to Merkel cell carcinoma than to pulmonary-type small cell carcinoma. This may explain why they are far less clinically aggressive than other small cell carcinomas.

Lack of evidence for basal or squamous cell carcinoma infection with Merkel cell polyomavirus in immunocompetent patients with Merkel cell carcinoma

Mixed Merkel cell carcinoma and squamous cell carcinoma of the skin

Merkel's cell carcinoma rarely arises in the vulva. It is unclear whether those cases arising in the vulva behave differently from the usual Merkel's cell carcinomas. A Merkel's cell carcinoma of the vulva was studied by light microscopy, immunohistochemistry, and electron microscopy. The clinical data of this case and of other reported cases are summarized and compared with those of Merkel's cell carcinoma in general. This tumor showed the characteristic trabecular pattern of Merkel's cell carcinoma. The tumor cells were immunoreactive to low-molecular-weight cytokeratin and neuron-specific enolase. This patient was treated initially with local excision. She died 17 months later with progressive metastatic disease unresponsive to chemotherapy. This case study and the review of six other cases indicate that Merkel's cell carcinoma of the vulva is universally metastatic, both to the regional lymph nodes and distant sites, and that it invariably follows a rapidly fatal course. Merkel's cell carcinoma of the vulva appears to have a biologic behavior more aggressive than that of Merkel's cell carcinoma in general. An initial modality combining chemotherapy, with or without irradiation, with aggressive surgery should be tried in future cases.

A case of combined Merkel cell carcinoma and squamous cell carcinoma: Molecular insights and diagnostic pitfalls

Merkel cell carcinoma associated with tofacitinib therapy

Merkel cell carcinoma (MCC), a high grade cutaneous neuroendocrine tumor (NET), is often confused with basal cell carcinoma (BCC), basaloid squamous cell carcinoma (SCC), and other primary site small cell carcinomas. Usually limited to skin and regional lymph nodes, solid organ metastasis is uncommon and results in high mortality. We present a case of a man with abdominal pain and liver lesions who was diagnosed with Merkel cell carcinoma of unknown primary (MCCUP). A 74-year-old man presented with a one-week history of shortness of breath, pleuritic chest pain, and abdominal pain. Significant medical history included prostate adenocarcinoma and Moh's surgery for SCC and BCC. On examination, he demonstrated epigastric tenderness. Laboratory studies were remarkable for elevated liver enzymes and total bilirubin. Initial workup ruled out acute coronary syndrome and pulmonary embolism; however, chest CT showed multiple pulmonary nodules and a large peri-fissural nodule. Abdominal CT showed a mottled liver and lytic lesions in the vertebral column concerning for metastasis. A liver biopsy showed high-grade NET. Immunohistochemical (IHC) staining favoring MCC and excluding primary pulmonary and gastrointestinal SCC. Hospital course was complicated by worsening jaundice and ascites for which he underwent palliative chemotherapy without improvement. Repeat imaging showed worsening hepatic metastases as well as new lytic lesions. There was a decrease in size of the peri-fissural nodule, but no change in the other lung nodules. Palliative radiation therapy was elected and the patient passed away 4 months after presentation. MCC is a rare, aggressive NET, most common in Caucasians over age 65 with UV exposure. Most patients present with cutaneous disease and regional lymph node involvement. Systemic spread is rare; however, common metastatic sites include lymph nodes, lung, liver, and bone. MCCUP typically presents with nodal disease without known primary cutaneous MCC. Histologic diagnosis of MCCUP is difficult due to similarities with more common high-grade NETs, such as pulmonary or gastrointestinal small cell carcinoma. Key electron microscopic features include dense core granules and paranuclear intermediate filaments. CK-20 positivity, and TTF-1 and CDX-2 negativity on IHC staining, to exclude pulmonary and gastrointestinal SCC, are confirmatory. Outcomes for patients with MCC is poor; treatment typically involves palliative chemotherapy.2349_A Figure 1. Computed Tomography of the Abdomen w/contrast - The liver is enlarged with a heterogeneous and mottled appearance - Axial section2349_B Figure 2. Needle biopsy of liver showing a trabecular small cell carcinoma (MCC) at 200 magnification (H&E 20X)2349_C Figure 3. Merkel cell carcinoma marking with CK20 in a para-nuclear pattern at 600 magnification (60X)

Beta Human Papillomavirus and Merkel Cell Polyomavirus in Skin Neoplasms

Merkel cell carcinoma (MCC) is an unusual primary cutaneous small cell neuroendocrine carcinoma that occurs predominantly in the head and neck region, but rarely in the oral cavity. A review of the English-language literature revealed only 2 cases of MCC that occurred intraorally and the present case was the second reported case of oral MCC arising in the oral mucobuccal fold. The patient, a 62-year-old Taiwanese female, noted a firm and painful swelling at her right cheek for three months. Intraoral examination of the lesion revealed an erythematous bulging mass involving both the right lower posterior mucobuccal fold and the right lower retromolar area. Incisional biopsy of the lesion via intraoral approach showed numerous uniform, small round cells with scanty cytoplasm and frequent mitoses, either typical or atypical. These cells were densely packed into nests infiltrating in a loose connective tissue stroma. The Merkel cell origin of the tumor is suggested by results from immunohistochemical studies. In these studies, most neoplastic cells showed a paranuclear, globular, and inclusion-like pattern of immunostaining with the antibodies to pancytokeratin (AE1+AE3) and neuron-specific enolase, features that are characteristic of MCC. The aggressiveness of the tumor was characterized by rapid growth, frequent regional lymph node and distant metastases. The patient died 8 months after the initial diagnostic biopsy.

The cellular origin of Merkel cell carcinoma (MCC) is controversial. We previously hypothesized that MCC originates from hair follicle stem cells or Merkel cell (MC) progenitors residing within the hair follicle bulge. Examination of three cases of combined MCC led to the unexpected discovery that numerous keratin 20 (CK20)-positive MCs within the squamous cell carcinoma (SCC) component of combined MCC appeared morphologically normal with dendritic and oval shapes. Moreover, one extremely rare case of combined SCC and MCC showed both intra-epidermal and dermal MCCs. These three cases represent the first documentation of MC hyperplasia in MCC, besides various benign follicular neoplasms associated with MC hyperplasia. Therefore, to elucidate the proliferating potential of MCs and their histogenetic relationship with MCCs, we further investigated these cases based on pathological observations. We identified numerous cells co-expressing CK20 and the proliferation marker Ki-67, identical to the morphological and immunohistochemical features of normal MCs. This finding indicated that MCs can no longer be considered as pure post-mitotic cells. Instead, they have proliferative potential under specific conditions in the diseased or wounded skin, or adjacent to various skin tumors, including MCC. Intimate co-existence of two malignant cell components composed of intradermal and intra-epidermal MCCs, with the proliferation of normal-appearing MCs in the same lesion, lends support to the hypothesis that MCs and MCC cells are derived from MC progenitors residing within the hair follicle bulge. Specifically, MCCs are derived from transformed MC progenitors with potential for dual-directional differentiation towards neuroendocrine and epithelial lineages.