Sebaceous tumours: more than skin deep.

CLINICAL PRESENTATION: A 77-year-old man presented to our skin cancer centre with various cutaneous tumours occurring in 2006-2017. Histopathology showed a 'hidradenocarcinoma' on the left upper back (2006) and a sebaceous adenoma (figure 1) on the left shoulder (2011). In 2017, he developed a sebaceous carcinoma on the middle upper back, which manifested as a slowly enlarging, asymptomatic nodule. Medical history was significant for curative resection of colorectal cancer in 1988.gutjnl;67/11/1957/F1F1F1Figure 1Clinical appearance of the sebaceous adenoma on the patient's left shoulder in 2011.The most recent lesion was subjected to extensive immunohistochemical assessment. The neoplastic cells were positive for cytokeratin 5/6, cytokeratin 7, cluster of differentiation antigen 10, adipophilin, androgen receptor, epithelial membrane antigen, KI67 antigen, MLH1 and PMS2, but stained negative for gross cystic disease fluid protein 15, prostate-specific antigen, carbohydrate antigen 19/9, CDX2 protein, hepatocyte-specific antigen, carcinoembryonic antigen, cluster of differentiation antigen 117 and cytokeratin 19. Given the variety of histological manifestations of the patient's skin neoplasms, further studies were performed. They revealed positive nuclear expression signals for MLH1, MSH6 and PMS2, whereas MSH2 expression was absent in almost all tumour cells (figure 2). Positron emission tomography (PET)/CT and colonoscopy did not detect any pathological findings. However, molecular genetic analysis of peripheral blood showed a heterozygous deletion of exon 7 of the MSH2 gene. Subsequently, several family members tested positive for MSH2 mutations and underwent genetic counselling.gutjnl;67/11/1957/F2F2F2Figure 2(A-D) Histopathological images of the patient's most recent lesion (diaminobenzidine, original magnification, ×100). The tumour cells demonstrated strong nuclear positivity for MLH1 (A) and PMS2 (B), but were essentially negative for MSH6 (C) and MSH2 (D). QUESTION: What is your diagnosis? DIAGNOSIS: Muir-Torre syndrome (MTS).

Angioplasmacellular hyperplasia - a new histopathologic clue for anogenital herpes simplex recidivans in immunocompromised patients?

Chronic herpes infections in immunocompromised patients exhibit uncommon features both on clinical and histopathologic levels, which can make correct diagnosis challenging. Better defining histopathologic criteria to identify chronic herpes infection in immunocompromised patients would be of great diagnostic value. In a single-center study, clinical and pathological data of herpes infections confirmed by biopsy was collected. We identified 42 cases overall, of which 21 were from immunocompromised patients and performed a detailed histopathologic pattern analysis of all lesions. In immunocompromised patients, vasculitis was seen in 2/21 cases (9.5%). Involvement of the sweat duct epithelium and/or sebaceous glands was observed in none of the HIV-infected patients but in 5/11 (45.4%) transplant patients with herpes infection. This feature was solely found in patients with acute herpetic lesions (5/5). In the process of histopathologic review, we identified a previously unrecognized morphological pattern of herpes simplex virus infection in immunocompromised patients. The individual clinical history and morphological pattern identified is described for multiple affected patients. In summary, in immunocompromised patients, histopathologic diagnosis of herpes infection can be challenging, in particular in chronic lesions, which lack the presentation of typical herpetic keratinocytes. In our study, we identify angioplasmacellular hyperplasia as a new histopathologic clue, which may be helpful in recognizing chronic herpes infection in immunocompromised patients. Further studies are warranted to implement this clue into routine diagnostics.

pHH3 immunostaining improves interobserver agreement of mitotic index in thin melanomas.

According to the seventh edition of the American Joint Committee on Cancer guidelines, the TNM staging category in thin cutaneous melanomas depends on the mitotic rate (MR). In this study, we analyze the interobserver agreement of the MR in a series of 92 thin cutaneous melanomas. Serial sections of the tumors were either stained with hematoxylin and eosin or immunohistochemically stained with pHH3, an antibody for phosphohistone H3, and analyzed by 4 observers. Determination of MR with pHH3 immunostaining resulted in higher sensitivity in counting mitosis for all observers. Moreover, interobserver agreement was higher with pHH3. Immunostaining with pHH3 is a sensitive method to detect mitosis in thin cutaneous melanomas, with good reproducibility of MR between independent observers. Further studies are needed to find out if higher sensitivity in the detection of mitosis by pHH3 immunostaining has additional prognostic relevance.

Association of toll-interacting protein gene polymorphisms with atopic dermatitis.

BACKGROUND: Atopic dermatitis (AD) is a common inflammatory skin disorder, affecting up to 15% of children in industrialized countries. Toll-interacting protein (TOLLIP) is an inhibitory adaptor protein within the toll-like receptor (TLR) pathway, a part of the innate immune system that recognizes structurally conserved molecular patterns of microbial pathogens, leading to an inflammatory immune response. METHODS: In order to detect a possible role of TOLLIP variation in the pathogenesis of AD, we screened the entire coding sequence of the TOLLIP gene by SSCP in 50 AD patients. We identified an amino acid exchange in exon 6 (Ala222Ser) and a synonymous variation in exon 4 (Pro139Pro). Subsequently, these two variations and four additional non-coding polymorphisms (-526 C/G, two polymorphisms in intron 1 and one in the 3'UTR) were genotyped in 317 AD patients and 224 healthy controls. RESULTS: The -526G allele showed borderline association with AD in our cohort (p = 0.012; significance level after correction for multiple testing 0.0102). Haplotype analysis did not yield additional information. Evaluation of mRNA expression by quantitative real-time polymerase chain reaction in six probands with the CC and six with the GG genotype at the -526 C/G locus did not reveal significant differences between genotypes. CONCLUSION: Variation in the TOLLIP gene may play a role in the pathogenesis of AD. Yet, replication studies in other cohorts and populations are warranted to confirm these association results.