Fast-Growing Frontal Subcutaneous Nodule in a Young Woman

A woman in her 20s presented with a firm, mobile, painful, fast-growing subcutaneous nodule in the glabella. What is your diagnosis?

Gastric metaplasia as a precursor of nonconventional dysplasia in inflammatory bowel disease

Gastric metaplasia in colonic mucosa with inflammatory bowel disease (IBD) develops as an adaptation mechanism. The association between gastric metaplasia and nonconventional and/or conventional dysplasia as precursors of colitis-associated colorectal cancer is unknown. To address this question, we retrospectively reviewed a series of 33 IBD colectomies to identify gastric metaplasia in 76 precursor lesions. We obtained 61 nonconventional and 15 conventional dysplasias. Among nonconventional dysplasia, 31 (50.8 %) were low-grade (LGD), 4 (6.5 %) were high-grade (HGD), 9 (14.8 %) had both LGD and HGD, and 17 (27.9 %) had no dysplasia (ND), while 14 (93 %) conventional dysplasias had LGD, and 1 (7 %) had LGD and HGD. Gastric metaplasia was assessed by concomitant immunoexpression of MUC5AC and loss of CDX2 staining. Expression of a p53-mut pattern was considered as a surrogate for gene mutation, and complete loss of MLH1 staining as presence of MLH1 hypermethylation. In nonconventional dysplasia, MUC5AC immunoexpression decreased as the degree of dysplasia increased, being 78 % in LGD and 39 % in HGD (p = 0.006). CDX2 was lost in epithelial glands with high expression of MUC5AC (p < 0.001). The p53-mut pattern was observed in 77 % HGD, 45 % LGD, and in 6 % with ND (p < 0.001). Neither nonconventional nor conventional dysplasia showed complete loss of MLH1 staining. Gastric metaplasia was also present in mucosa adjacent to nonconventional dysplasia with chronic changes or active inflammation. Our results show that gastric metaplasia appears in IBD-inflamed colon mucosa, it is the substrate of most nonconventional dysplasia and occurs prior to p53 alterations.

Hemosiderotic Xanthelasmas. A New Clinicopathological Variant of Xanthelasma Palpebrarum or a Localized Variant of Xanthosiderohistiocytosis of the Eyelids?

ABSTRACT

Xanthelasma palpebrarum represent the most common subtype of cutaneous plane xanthomas. Xanthosiderohistiocytosis is considered a rare variant of xanthoma disseminatum, with only 4 cases reported to date. We report the case of a man with progressive pigmented lesions on the 4 eyelids that could correspond to hemosiderotic xanthelasmas or a localized variant of xanthosiderohistiocytosis.

Alterations in p53, Microsatellite Stability and Lack of MUC5AC Expression as Molecular Features of Colorectal Carcinoma Associated with Inflammatory Bowel Disease

Colitis-associated colorectal carcinoma (CAC) occurs in inflammatory bowel disease (IBD) because of the "chronic inflammation-dysplasia-cancer" carcinogenesis pathway characterized by p53 alterations in the early stages. Recently, gastric metaplasia (GM) has been described as the initial event of the serrated colorectal cancer (CRC) process, resulting from chronic stress on the colon mucosa. The aim of the study is to characterize CAC analyzing p53 alterations and microsatellite instability (MSI) to explore their relationship with GM using a series of CRC and the adjacent intestinal mucosa. Immunohistochemistry was performed to assess p53 alterations, MSI and MUC5AC expression as a surrogate for GM. The p53 mut-pattern was found in more than half of the CAC, most frequently stable (MSS) and MUC5AC negative. Only six tumors were unstable (MSI-H), being with p53 wt-pattern (p = 0.010) and MUC5AC positive (p = 0.005). MUC5AC staining was more frequently observed in intestinal mucosa, inflamed or with chronic changes, than in CAC, especially in those with p53 wt-pattern and MSS. Based on our results, we conclude that, as in the serrated pathway of CRC, in IBD GM occurs in inflamed mucosa, persists in those with chronic changes and disappears with the acquisition of p53 mutations.

Adalimumab Biosimilar-Induced Autoimmunity-Related Sweet-Like Neutrophilic Dermatosis

ABSTRACT

Antitumor necrosis factor therapies have shown to produce a broad range of cutaneous eruptions. We report the case of a patient under adalimumab biosimilar treatment for a punctate inner choroidopathy who developed a cutaneous eruption on sun-exposed areas that showed a diffuse dermal neutrophilic infiltrate consistent with a Sweet-like neutrophilic dermatosis and some features of autoimmunity.

Sentinel Lymph Node Biopsy vs. Observation in Thin Melanoma: A Multicenter Propensity Score Matching Study

The therapeutic value of sentinel lymph node biopsy (SLNB) in thin melanoma remains controversial. The aim of this study is to determine the role of SLNB in the survival of thin melanomas (≤1 mm). A multicenter retrospective observational study was designed. A propensity score matching was performed to compare patients who underwent SLNB vs. observation. A multivariate Cox regression was used. A total of 1438 patients were matched by propensity score. There were no significant differences in melanoma-specific survival (MSS) between the SLNB and observation groups. Predictors of MSS in the multivariate model were age, tumor thickness, ulceration, and interferon treatment. Results were similar for disease-free survival and overall survival. The 5- and 10-year MSS rates for SLN-negative and -positive patients were 98.5% vs. 77.3% (p < 0.001) and 97.3% vs. 68.7% (p < 0.001), respectively. SLNB does not improve MSS in patients with thin melanoma. It also had no impact on DSF or OS. However, a considerable difference in MSS, DFS, and OS between SLN-positive and -negative patients exists, confirming its value as a prognostic procedure and therefore we recommend discussing the option of SLNB with patients.

Histopathologic Spectrum of Findings Associated With Tattoos: Multicenter Study Series of 230 Cases

IMPORTANCE

Reactions to tattoo may simulate common dermatosis or skin neoplasms. Histopathology allows diagnosis and helps determining the level and degree of inflammation associated, consequently orientating treatment.

OBJECTIVE

To describe the histological features found in biopsies of cutaneous reactions to tattoo.

DESIGN

This study was designed as a multicenter case series.

SETTING

All consecutive histopathological samples of tattoos referred from 1992 to 2019 to the Hospital General de Catalunya, Hospital Germans Trias i Pujol, and a private practice, all in Barcelona, Spain, and from the Kempf und Pfaltz Histologische Diagnostik in Zurich, Switzerland were retrieved from the files.

PARTICIPANTS AND EXPOSURE

The inclusion criteria were all cosmetic/permanent makeup, artistic/professional, and traumatic tattoos associated with either inflammatory reactions alone and/or with tumors and/or infections. Exclusion criteria were cases without any associated pathologic finding in the place of the ink, amalgam tattoos, and medical or temporary tattoos.

MAIN OUTCOMES AND MEASURES

In all patients, clinical features (age, sex, location, tattoo color, and presentation) were recorded. Histological features evaluated included ink color, associated tumors or infections, and inflammatory reaction pattern. Inflammation was graded in low to moderate or severe.

RESULTS

From 477 biopsies diagnosed as tattoos, 230 cases from 226 patients met the inclusion criteria. Samples corresponded to 107 male and 120 female subjects and 3 of unknown gender. Median age was 39 years (ranging from 9 to 84 years). Fifty-three samples were referred from centers in Spain and 177 from the center in Switzerland. The series was analyzed in 2 parts: tattoos associated only with inflammatory reactions (117/230) and tattoos associated with tumors or infections (113/230). The most common form of inflammatory pattern associated with tattoo was the fibrosing reaction (79/117, 68%), followed by granulomatous reaction (56/117, 48%), lichenoid reaction (33/117, 28%), epithelial hyperplasia (28/117, 24%), pseudolymphoma (27/117, 23%) and spongiotic reaction (27/117, 23%). Combined features of 2 or more types of inflammatory patterns were seen in 64% cases.

CONCLUSIONS AND RELEVANCE

Our series confirms that cutaneous reactions to tattoos are polymorphous. Inflammation tends to present with combined patterns. Infections are tending to decline, and pathologic findings are not specific to ink color or clinical features.

Oral submucous fibrosis presenting with histopathological lichenoid changes as predominant feature: Report of five cases and review of the literature

Oral submucous fibrosis (OSF) is a precancerous condition of the oral cavity associated with habitual chewing of quid, with a high incidence among populations of the Indian subcontinent and Southeast Asia. Clinically, its initial manifestation may mimic oral lichen planus or lichen sclerosus. If the habit is not halted, the mucosa gets leathery and thickened, and fibrous bands form causing significant morbidity. Microscopically, it is characterized by atrophic epithelium, loss of rete ridges, and hyalinization of lamina propria. Of note, these hallmark histopathological features may be overlooked in the unusual presence of lichenoid interface changes, which may lead to the wrong diagnosis. We present herein five cases in which the rare joint appearance of OSF and lichenoid reaction features posed a diagnostic challenge. Due to its progressive nature and malignant potential, the presence of oral lichenoid changes overlying submucous hyalinization, in the right clinical and demographic setting, should raise suspicion of OSF and prompt actions directed at quid-chewing discontinuation.

Protocol for the Histologic Diagnosis of Cutaneous Melanoma: Consensus Statement of the Spanish Society of Pathology and the Spanish Academy of Dermatology and Venereology (AEDV) for the National Cutaneous Melanoma Registry

This article describes a proposed protocol for the histologic diagnosis of cutaneous melanoma developed for the National Cutaneous Melanoma Registry managed by the Spanish Academy of Dermatology and Venereology (AEDV). Following a review of the literature, 36 variables relating to primary tumors, sentinel lymph nodes, and lymph node dissection were evaluated using the modified Delphi method by a panel of 8 specialists (including 7 pathologists). Consensus was reached on the 30 variables that should be included in all pathology reports for cutaneous melanoma and submitted to the Melanoma Registry. This list can also serve as a model to guide routine reporting in pathology departments.

[Protocol for the histologic diagnosis of cutaneous melanoma: consensus statement of the Spanish Society of Pathology and the Spanish Academy of Dermatology and Venereology (AEDV) for the National Cutaneous Melanoma Registry]

This article describes a proposed protocol for the histologic diagnosis of cutaneous melanoma developed for the National Cutaneous Melanoma Registry managed by the Spanish Academy of Dermatology and Venereology (AEDV). Following a review of the literature, 36 variables relating to primary tumors, sentinel lymph nodes, and lymph node dissection were evaluated using the modified Delphi method by a panel of 8 specialists (including 7 pathologists). Consensus was reached on the 30 variables that should be included in all pathology reports for cutaneous melanoma and submitted to the Melanoma Registry. This list can also serve as a model to guide routine reporting in pathology departments.

Pseudoxanthoma elasticum-like papillary dermal elastolysis in non-exposed skin

Pseudoxanthoma elasticum-like papillary dermal elastolysis is an acquired elastic tissue disorder clinically similar to pseudoxanthoma elasticum in the absence of systemic involvement. Histopathologically, special staining of elastic fibers demonstrates a total or partial band-like loss of elastic fibers in the papillary dermis. Although ultraviolet radiation seems to be one of the main etiological factors in this entity, we report a case of pseudoxanthoma elasticum-like papillary dermal elastolysis on the neck of a woman who wore hijab.

Erythroderma as first manifestation of squamous cell lung cancer: rare case report

Erythroderma as the first manifestation of a solid organ malignancy is rare. The underlying cancer is a challenging condition to diagnose. There are a few cases of erythroderma in cancer patients reported in the literature. We here describe the case of a 70-year-old man who presented with asthenia, weight loss, dry cough and total body erythema with desquamation over the past month. A chest computed tomography scan showed a nodular lesion, which was finally diagnosed as a squamous cell lung carcinoma. To our knowledge, as an erythroderma presentation, only 13 cases have been reported in the literature. This case report demonstrates the need to search for a neoplasm in patients presenting with erythroderma, particularly in the presence of accompanying debilitating symptoms.

Anti-Siglec-1 antibodies block Ebola viral uptake and decrease cytoplasmic viral entry

Several Ebola viruses cause outbreaks of lethal haemorrhagic fever in humans, but developing therapies tackle only Zaire Ebola virus. Dendritic cells (DCs) are targets of this infection in vivo. Here, we found that Ebola virus entry into activated DCs requires the sialic acid-binding Ig-like lectin 1 (Siglec-1/CD169), which recognizes sialylated gangliosides anchored to viral membranes. Blockage of the Siglec-1 receptor by anti-Siglec-1 monoclonal antibodies halted Ebola viral uptake and cytoplasmic entry, offering cross-protection against other ganglioside-containing viruses such as human immunodeficiency virus type 1.

The Depolarized Expression of the Alpha-6 Integrin Subunit in the Endometria of Women With Endometriosis

OBJECTIVE

The current study sought to compare the endometrial localization of the integrin subunit alpha-6 in women with endometriosis and women without the disease. Alpha-6 integrins have an important function, not only in the attachment of cells to the extracellular matrix and laminin, but they also serve as inductors of cell migration and invasion, depending on their pattern of expression in the cell membrane.

METHODS

The endometriosis group consisted of 32 women with a confirmed diagnosis of endometriosis by laparoscopy or laparotomy. The control group consisted of 20 women not having endometriosis or any other gynecologic disease at laparoscopy. Endometria were obtained by biopsy. Immunohistochemical techniques were used to assess alpha-6 localization. In each section, the percentage of positive cells and the localization of expression were evaluated.

RESULTS

All glandular cells expressed alpha-6 in all of the samples but presented two different patterns, either only in the basal side of the cells (polarized) or also in other sides of the cells (depolarized). The percentage of samples showing depolarized expression was significantly higher in the endometriosis group (66.6% vs 15.8%, chi2 =12.09, P = .001).

CONCLUSIONS

The endometria of women with endometriosis more frequently show a depolarized expression of integrin subunit alpha-6, a characteristic usually found in highly proliferating cells with migrating and invasive abilities.

Aberrant gene methylation and bronchial dysplasia in high risk lung cancer patients

INTRODUCTION

The risk for lung cancer is incremented in high degree dysplasia (HGD) and in subjects with hypermethylation of multiple genes. We sought to establish the association between them, as well as to analyze the DNA aberrant methylation in sputum and in bronchial washings (BW).

METHODS

Cross sectional study of high risk patients for lung cancer in whom induced sputum and autofluorescence bronchoscopy were performed. The molecular analysis was determined on DAPK1, RASSF1A and p16 genes using Methylation-specific PCR.

RESULTS

A total of 128 patients were enrolled in the study. Dysplasia lesions were found in 79 patients (61.7%) and high grade dysplasia in 20 (15.6%). Ninety eight patients out of 128 underwent molecular analysis. Methylation was observed in bronchial secretions (sputum or BW) in 60 patients (61.2%), 51 of them (52%) for DAPK1, in 20 (20.4%) for p16 and in three (3.1%) for RASSF1A. Methylated genes only found in sputum accounted for 38.3% and only in BW in 41.7%, and in both 20.0%. In the 11.2% of the patients studied, HGD and a hypermethylated gene were present, while for the 55.1% of the sample only one of both was detected and for the rest of the subjects (33.6%), none of the risk factors were observed.

CONCLUSIONS

Our data determines DNA aberrant methylation panel in bronchial secretions is present in a 61.2% and HGD is found in 15.6%. Although both parameters have previously been identified as risk factors for lung cancer, the current study does not find a significative association between them. The study also highlights the importance of BW as a complementary sample to induced sputum when analyzing gene aberrant methylation.

Lupus erythematosus tumidus: a clinical and histological study of 25 cases

Background

Lupus erythematosus tumidus (LET) is a subtype of cutaneous lupus erythematosus (CLE) that has been well characterized in recent years. However, some controversy still remains concerning the histological features of epidermal involvement.

Objectives

The objective of this report is to describe the clinical and microscopic features of LET in patients diagnosed at Hospital Universitari Germans Trias i Pujol, Spain.

Methods

We conducted a retrospective study of 25 patients with a diagnosis of LET.

Results

All patients presented with typical LET lesions (smooth, erythematous plaques without macroscopic epidermal changes, such as follicular plugs or scale, that resolved without residual scarring or hypopigmentation). None of the patients fulfilled the criteria for systemic lupus erythematosus during follow-up. Test results for antinuclear antibodies were positive in five patients (20%), with titres below one of 320 in all cases. Twenty-two patients (88%) required antimalarial therapy; response was good in 70% and moderate response in 30%. Minor epidermal alterations were observed in 52% of biopsy specimens, with focal basal vacuolization being the most frequent.

Conclusions

LET is a variant of CLE that has distinctive clinical, histologic and prognostic features. Unlike the patients in the case series previously described in the literature, most of our patients required treatment with antimalarials. Histology revealed mild epidermal alterations in a significant percentage of patients. Thus, in our opinion, the absence of microscopic epidermal alterations is not constant in LET.

Cutaneous lupus erythematosus on the elbows: a peculiar localization

Background: The presence of lesions limited to the elbows as expression of a cutaneous lupus erythematosus (CLE) is very unusual.

Objectives: To describe the clinical and microscopic characteristics of these lesions, as well as their relationship with the different cutaneous lupus erythematosus subsets.

Methods: Seven cases of CLE with lesions on the elbows, collected from 1998 to 2009, were retrospectively analysed. All patients had a previous or concomitant diagnosis of lupus erythematosus based on other typical skin lesions for each subtype of lupus erythematosus, and they all met clinical and microscopic criteria.

Results: Six patients were women with a mean age of 33.8 years. Five cases had been previously diagnosed with CLE (three lupus erythematosus [LE] tumidus, one subacute CLE and one acute CLE). In the other two cases, these lesions were the first manifestation of the disease. The lesions consisted of pruriginous, erythematous papules and plaques with a slightly scaly surface, located on both elbows. Microscopically, in addition to the typical features of CLE, other changes were observed, including alterations in the texture and the staining properties of collagen fibres (five cases), an interstitial histiocytic infiltrate (four cases), eosinophils (one case) and a Churg–Strauss granuloma (one case).

Conclusions: These peculiar lesions located on the elbows should be included in the spectrum of cutaneous manifestations of LE. Their histopathology combines changes of both LE and interstitial granulomatous dermatitis.

Subcutaneous Granuloma Annulare

Subcutaneous granuloma annulare is a rare clinicopathologic variant of granuloma annulare, characterized by subcutaneous nodules that may appear alone or in association with intradermal lesions. The pathogenesis of this deep variant of granuloma annulare remains uncertain. Subcutaneous granuloma annulare appears more frequently in children and young adults, and the lesions consist of subcutaneous nodules with no inflammatory appearance at the skin surface, most commonly located on the anterior aspects of the lower legs, hands, head, and buttocks. Usually, subcutaneous granuloma annulare is an authentic and exclusive panniculitic process with no dermal participation, although in 25% of the patients lesions of subcutaneous granuloma annulare coexist with the classic findings of granuloma annulare in the dermis. Histopathologically, subcutaneous granuloma annulare consist of areas of basophilic degeneration of collagen bundles with peripheral palisading granulomas involving the connective tissue septa of the subcutis. Usually, the area of necrobiosis in subcutaneous granuloma annulare is larger than in the dermal counterpart. The central necrobiotic areas contain increased amounts of connective tissue mucin and nuclear dust from neutrophils between the degenerated collagen bundles. Eosinophils are more common in subcutaneous granuloma annulare than in the dermal counterpart. There are not descriptions of subcutaneous granuloma annulare showing a histopathologic pattern of the so-called incomplete or interstitial variant. Histopathologic differential diagnosis of subcutaneous granuloma annulare includes rheumatoid nodule, necrobiosis lipoidica and epithelioid sarcoma.

The endometria of patients with endometriosis show higher expression of class I human leukocyte antigen than the endometria of healthy women

OBJECTIVE

To compare the expression of class I human leukocyte antigen (HLA I) in endometrial samples from patients with and without endometriosis.

DESIGN

Cross-sectional study.

SETTING

Acute-care teaching hospital in Barcelona, Spain.

PATIENT(S)

The endometriosis group included 32 patients for whom the only diagnosis during an operation was endometriosis. The control group included 20 women who underwent a laparoscopy and in whom no evidence of endometriosis or any other genital disease was seen.

INTERVENTION(S)

Samples of endometrium were obtained by curettage and immediately frozen. A pan-HLA I mouse antihuman IgG2a monoclonal antibody was used for immunohistochemical study.

MAIN OUTCOME MEASURE(S)

Frequency of positive glandular and stromal cells was evaluated in each section.

RESULT(S)

A significantly higher expression of HLA I in the endometriosis group than in controls, both in the glandular cells (median 100% vs. 80%) and in the stromal cells (median 60% vs. 20%), was observed.

CONCLUSION(S)

Patients with endometriosis had a significantly higher expression of HLA I molecules in endometrial cells than did the controls. This could be a possible explanation for their higher resistance to natural killer cytolysis.

High prevalence of Mycobacterium tuberculosis DNA in biopsies from sarcoidosis patients from Catalonia, Spain

BACKGROUND

Sarcoidosis is a systemic granulomatous disease of unknown etiology. The presence of mycobacterial nucleic acid components in patients with sarcoidosis has been demonstrated with varying degrees of success.

OBJECTIVES

The aim of this study was to estimate the presence of Mycobacterium tuberculosis DNA in tissues from sarcoidosis patients, in Catalonia, Spain, as well as to assess the long-term clinical course in these patients.

METHODS

Fifty-eight paraffin-embedded tissue biopsies corresponding to cases of sarcoidosis (n = 23), lung neoplasm (n = 23), and lung tuberculosis (n = 12) available in 1996 were analyzed in a retrospective study by means of a nested polymerase chain reaction using primers corresponding to the insertion element IS6110 of M. tuberculosis complex. For greater sensitivity, Southern blot hybridization was performed. Clinical data were recorded prior to and after PCR analysis (follow-up reported until 2002).

RESULTS

M. tuberculosis DNA was present in 9 out of 23 sarcoidosis biopsies (39%), in 1 out of 23 control patients (4%) (p < 0.01), and in all tissue samples from the 12 control patients with tuberculosis. To date, none of these sarcoidosis patients has developed tuberculosis over a mean (+/-SD) follow-up period of 11 (+/-3.4) years.

CONCLUSION

In our setting, M. tuberculosis DNA is present in tissue biopsies of significantly more sarcoidosis patients than controls. However, these results do not demonstrate causality, although they may suggest a link between M. tuberculosis infection and sarcoidosis in some cases. Follow-up of these patients suggests that M. tuberculosis-DNA-positive sarcoidosis patients are not at greater risk of developing tuberculosis than M. tuberculosis-DNA-negative patients.

Adverse cutaneous reactions to anakinra in patients with rheumatoid arthritis: clinicopathological study of five patients

BACKGROUND

Anakinra, a recombinant human form of interleukin-1 receptor antagonist, is used to treat patients with active rheumatoid arthritis (RA).

OBJECTIVES

To report five patients with cutaneous adverse drug reactions due to anakinra and to evaluate the histopathological and immunohistochemical findings with the aim of understanding the possible mechanisms involved.

METHODS

Five patients of a series of 10 patients with RA undergoing treatment with anakinra in a clinical trial presented inflammatory lesions at the anakinra injection sites. In each case, clinical features were recorded and skin biopsy specimens were obtained. In one patient sequential biopsy specimens were obtained from skin lesions at different stages of development. Tissue sections of the biopsy specimens were stained with haematoxylin and eosin and May-Grünwald-Giemsa, and were immunoreacted with antibodies to leucocyte common antigen, CD68, CD3, CD45RO, CD20 and CD45RA.

RESULTS

The onset of reaction was within the first month of treatment and appeared as well-defined erythema and oedema involving the injection sites. In two patients the treatment had to be discontinued because of the skin reaction, and in one patient it was associated with systemic involvement. All biopsy specimens exhibited marked dermal oedema and a lichenoid dermal infiltrate composed mainly of lymphomononuclear cells with prominent populations of eosinophils and large CD68+ dermal macrophages and an increase in the number of mast cells, which were spindle shaped in a significant proportion.

CONCLUSIONS

Cutaneous toxicity is a frequent, usually well-tolerated complication of treatment with anakinra in patients with RA, although in some cases it can be associated with systemic involvement. The most relevant histopathological findings include dermal oedema and a lichenoid, perivascular and periadnexal predominantly lymphomononuclear infiltrate, with many eosinophils and the presence of enlarged CD68+ macrophages. These findings resemble those seen in skin reactions in patients receiving chemotherapy and colony-stimulating factors. We also found an increase in mast cell numbers that could be a specific effect of anakinra.

Prognostic significance of p27Kip1, p45Skp2 and Ki67 expression profiles in Merkel cell carcinoma, extracutaneous small cell carcinoma, and cutaneous squamous cell carcinoma

AIMS

To compare the immunohistochemical expression of prognostic markers p27(Kip1), p45(Skp2) and Ki67 in Merkel cell carcinoma (primary neuroendocrine carcinoma of the skin, MCC), small cell neuroendocrine carcinoma of lung and urinary bladder (SNC), and cutaneous squamous cell carcinoma (SCC).

METHODS AND RESULTS

Immunohistochemistry was performed using antibodies directed against p27(Kip1), p45(Skp2) and Ki67 on 72 tumour cases: 24 MCC, 25 SCC, and 23 SNC (15 from the lung and eight from the urinary bladder). Percentages of positive cells were determined for each marker and statistically analysed. Expression profiles on MCC and SCC were significantly different for all three markers. MCC and SNC exhibited significant similarities in their p27(Kip1) and p45(Skp2) expression profiles. In contrast, MCC and SNC differed significantly in their Ki67 proliferation indices, which were much higher in SNC. Additionally, MCC cases showed an association between increased proliferation indices and the appearance of local recurrence(s) and/or metastases.

CONCLUSION

The immunohistochemical profile of MCC differs from that of SCC, in spite of their common oncogenesis and the supposed metaplastic origin of MCC, and resembles that of SNC, except for Ki67 levels, which were higher in the latter (characterized by greater biological aggressiveness). High levels of Ki67 also appear to be a prognostic factor in MCC.

High level of coreceptor-independent HIV transfer induced by contacts between primary CD4 T cells

Cell-to-cell virus transmission is one of the most efficient mechanisms of human immunodeficiency virus (HIV) spread, requires CD4 and coreceptor expression in target cells, and may also lead to syncytium formation and cell death. Here, we show that in addition to this classical coreceptor-mediated transmission, the contact between HIV-producing cells and primary CD4 T cells lacking the appropriate coreceptor induced the uptake of HIV particles by target cells in the absence of membrane fusion or productive HIV replication. HIV uptake by CD4 T cells required cellular contacts mediated by the binding of gp120 to CD4 and intact actin cytoskeleton. HIV antigens taken up by CD4 T cells were rapidly endocytosed to trypsin-resistant compartments inducing a partial disappearance of CD4 molecules from the cell surface. Once the cellular contact was stopped, captured HIV were released as infectious particles. Electron microscopy revealed that HIV particles attached to the surface of target cells and accumulated in large (0.5-1.0 microm) intracellular vesicles containing 1-14 virions, without any evidence for massive clathrin-mediated HIV endocytosis. The capture of HIV particles into trypsin-resistant compartments required the availability of the gp120 binding site of CD4 but was independent of the intracytoplasmic tail of CD4. In conclusion, we describe a novel mechanism of HIV transmission, activated by the contact of infected and uninfected primary CD4 T cells, by which HIV could exploit CD4 T cells lacking the appropriate coreceptor as an itinerant virus reservoir.

A prospective study of the incidence of skin cancer and its risk factors in a Spanish Mediterranean population of kidney transplant recipients

BACKGROUND

Skin cancer is the most common malignancy occurring in kidney transplant recipients (KTRs).

OBJECTIVES

Our purpose was to investigate, prospectively, the cumulative incidence of cancerous and precancerous skin lesions as well as their risk factors in a close follow-up population of KTRs from a Mediterranean area of Spain.

PATIENTS AND METHODS

One hundred and seventy-four consecutive KTRs were examined at the moment of transplant and then at 6-month intervals. The cumulative incidence of skin cancer was computed. To analyse the role of potential risk factors (age at transplantation, cause of renal failure, duration of pretransplant dialysis, type of immunosuppressive regimen, sun-reactive skin type and history of occupational sun exposure), the Cox regression method was used.

RESULTS

After a median follow-up of 72 months (range, 12-140), 39 patients (25.3%) developed 142 tumours [84 basal cell carcinoma (BCC) and 58 squamous cell carcinoma (SCC)]. The BCC/SCC ratio was 1.4 : 1. The cumulative incidence for skin cancer was 13% after 3 years of graft survival, increasing to 27.5% at 6 years and 48% at 10 years. Only age at the time of transplantation and occupational sun exposure had statistical significance as risk factors (P < 0.001).

CONCLUSIONS

Our study confirms the high incidence of non-melanoma skin cancer among KTRs in a Mediterranean population with occupational sun exposure and the patient's age at the time of transplantation being the main risk factors. We believe that all organ transplant programs should provide educational information about protecting oneself from the sun as well as include follow-up visits by dermatologists in order to facilitate early diagnosis and treatment of skin cancer.