Mosaic Muir Torre Syndrome: Keratoacanthoma as a Piece of the Puzzle.

ABSTRACT: Lynch syndrome is an inherited condition, which increases the risk of numerous visceral malignancies and cutaneous tumors such as keratoacanthomas and sebaceous tumors. It is typically identified by immunohistochemistry of tissue taken from tumors or through genetic testing with next-generation sequencing. Diagnosing Lynch syndrome becomes more complex when the individual is mosaic for the relevant pathogenic variant. There are very few cases of this reported in the medical literature. It is even more unusual for the diagnosis to be made based on testing of a keratoacanthoma lesion. We report a case where immunohistochemistry of a keratoacanthoma helped make a diagnosis of mosaic Lynch syndrome. We will explore how mosaicism should be considered when a phenotype is strong, even if next-generation sequencing reports no pathogenic or likely pathogenic variant and how lesions such as keratoacanthomas can have a role in the early detection and treatment of future malignancies.

Coexistence of psoriasis and cutaneous T-cell lymphoma.

It has been reported that individuals with psoriasis are at an increased risk of developing cutaneous T-cell lymphoma (CTCL). However, the increased risk of lymphoma in these patients has been questioned because CTCL in its early stages may be incorrectly labelled as psoriasis, thus introducing potential for misclassification bias. We retrospectively reviewed patients with a confirmed diagnosis of CTCL seen in a tertiary cutaneous lymphoma clinic (n = 115) over a 5-year period and found that 6 (5.2%) patients had clinical evidence of coexisting psoriasis. This demonstrates that there is a small cohort of individuals who develop both psoriasis and CTCL.

CD8+CD103+ tissue-resident memory T cells convey reduced protective immunity in cutaneous squamous cell carcinoma.

BACKGROUND: Tumor infiltrating lymphocytes play a key role in antitumor responses; however, while several memory T-cell subtypes have been reported in inflammatory and neoplastic conditions, the proportional representation of the different subsets of memory T cells and their functional significance in cancer is unclear. Keratinocyte skin cancer is one of the most common cancers globally, with cutaneous squamous cell cancer (cSCC) among the most frequent malignancies capable of metastasis. METHODS: Memory T-cell subsets were delineated in human cSCCs and, for comparison, in non-lesional skin and blood using flow cytometry. Immunohistochemistry was conducted to quantify CD103+ cells in primary human cSCCs which had metastasized (P-M) and primary cSCCs which had not metastasized (P-NM). TIMER2.0 (timer.cistrome.org) was used to analyze TCGA cancer survival data based on ITGAE expression. Immunofluorescence microscopy was performed to determine frequencies of CD8+CD103+ cells in P-M and P-NM cSCCs. RESULTS: Despite intertumoral heterogeneity, most cSCC T cells were CCR7-/CD45RA- effector/resident memory (TRM) lymphocytes, with naive, CD45RA+/CCR7- effector memory re-expressing CD45RA, CCR7+/L-selectin+ central memory and CCR7+/L-selectin- migratory memory lymphocytes accounting for smaller T-cell subsets. The cSCC CD8+ T-cell population contained a higher proportion of CD69+/CD103+ TRMs than that in non-lesional skin and blood. These cSCC CD69+/CD103+ TRMs exhibited increased IL-10 production, and higher CD39, CTLA-4 and PD-1 expression compared with CD103- TRMs in the tumor. CD103+ cells were more frequent in P-M than P-NM cSCCs. Analysis of TCGA data demonstrated that high expression of ITGAE (encoding CD103) was associated with reduced survival in primary cutaneous melanoma, breast carcinoma, renal cell carcinoma, kidney chromophobe cancer, adrenocortical carcinoma and lower grade glioma. Immunofluorescence microscopy showed that the majority of CD103 was present on CD8+ T cells and that CD8+CD103+ cells were significantly more frequent in P-M than P-NM cSCCs. CONCLUSION: These results highlight CD8+CD103+ TRMs as an important functional T-cell subset associated with poorer clinical outcome in this cancer.

Breast cancer in patients with germline TP53 pathogenic variants have typical tumour characteristics: the Cohort study of TP53 carrier early onset breast cancer (COPE study).

Germline TP53 pathogenic variants are rare but associated with a high risk of cancer; they are often identified in the context of clinically diagnosed Li-Fraumeni syndrome predisposing to a range of young onset cancers including sarcomas and breast cancer. The study aim was to conduct a detailed morphological review and immuno-phenotyping of breast cancer arising in carriers of a germline TP53 pathogenic variant. We compared breast cancers from five defined groups: (1) TP53 carriers with breast cancer (n = 59), (2) early onset HER2-amplified breast cancer, no germline pathogenic variant in BRCA1/2 or TP53 (n = 55), (3) BRCA1 pathogenic variant carriers (n = 60); (4) BRCA2 pathogenic variant carriers (n = 61) and (5) young onset breast cancer with no known germline pathogenic variant (n = 98). Pathologists assessed a pre-agreed set of morphological characteristics using light microscopy. Immunohistochemistry (IHC) for HER2, ER, PR, p53, integrin alpha v beta 6 (αvß6) integrin, α-smooth muscle actin (α-SMA) and pSMAD2/3 was performed on tissue microarrays of invasive carcinoma. We confirmed a previously reported high prevalence of HER2-amplified, ductal no special type invasive breast carcinoma amongst known TP53 germline pathogenic variant carriers 20 of 36 (56%). Furthermore we observed a high frequency of densely sclerotic tumour stroma in cancers from TP53 carriers (29/36, 80.6%) when compared with non-carriers, 50.9% (28/55), 34.7% (50/144), 41.4% (65/157), 43.8% (95/217) in groups 2-5 respectively. The majority of germline TP53 gene carrier breast tumours had a high intensity of integrin αvß6, α-SMA and pSMAD2/3 expression in the majority of cancer cells. In conclusion, aggressive HER2 positive breast cancers with densely sclerotic stroma are common in germline TP53 carriers. High levels of αvß6 integrin, α-SMA and pSMAD2/3 expression suggest that the dense stromal phenotype may be driven by upregulated transforming growth factor beta signalling.

Impact of Molecular Subtypes in Muscle-invasive Bladder Cancer on Predicting Response and Survival after Neoadjuvant Chemotherapy.

BACKGROUND: An early report on the molecular subtyping of muscle-invasive bladder cancer (MIBC) by gene expression suggested that response to neoadjuvant chemotherapy (NAC) varies by subtype. OBJECTIVE: To investigate the ability of molecular subtypes to predict pathological downstaging and survival after NAC. DESIGN, SETTING, AND PARTICIPANTS: Whole transcriptome profiling was performed on pre-NAC transurethral resection specimens from 343 patients with MIBC. Samples were classified according to four published molecular subtyping methods. We developed a single-sample genomic subtyping classifier (GSC) to predict consensus subtypes (claudin-low, basal, luminal-infiltrated and luminal) with highest clinical impact in the context of NAC. Overall survival (OS) according to subtype was analyzed and compared with OS in 476 non-NAC cases (published datasets). INTERVENTION: Gene expression analysis was used to assign subtypes. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Receiver-operating characteristics were used to determine the accuracy of GSC. The effect of GSC on survival was estimated by Cox proportional hazard regression models. RESULTS AND LIMITATIONS: The models generated subtype calls in expected ratios with high concordance across subtyping methods. GSC was able to predict four consensus molecular subtypes with high accuracy (73%), and clinical significance of the predicted consensus subtypes could be validated in independent NAC and non-NAC datasets. Luminal tumors had the best OS with and without NAC. Claudin-low tumors were associated with poor OS irrespective of treatment regimen. Basal tumors showed the most improvement in OS with NAC compared with surgery alone. The main limitations of our study are its retrospective design and comparison across datasets. CONCLUSIONS: Molecular subtyping may have an impact on patient benefit to NAC. If validated in additional studies, our results suggest that patients with basal tumors should be prioritized for NAC. We discovered the first single-sample classifier to subtype MIBC, which may be suitable for integration into routine clinical practice. PATIENT SUMMARY: Different molecular subtypes can be identified in muscle-invasive bladder cancer. Although cisplatin-based neoadjuvant chemotherapy improves patient outcomes, we identified that the benefit is highest in patients with basal tumors. Our newly discovered classifier can identify these molecular subtypes in a single patient and could be integrated into routine clinical practice after further validation.

Primary Clear Cell Microcystic Adenoma of the Sinonasal Cavity: Pathological or Fortuitous Association?

Primary clear cell microcystic adenoma of the sinonasal cavity is rare. It has previously been described only as a VHL-associated tumour. Von Hippel-Lindau (VHL) syndrome is an inherited cancer syndrome characterised by an elevated risk of neoplasia including clear cell renal cell carcinoma (ccRCC), haemangioblastoma, and phaeochromocytoma. We describe the second reported case of a primary clear cell microcystic adenoma of the sinonasal cavity. The 39-year-old patient with VHL syndrome had previously undergone resection and ablation of ccRCC. He presented with epistaxis. Imaging demonstrated a mass in the ethmoid sinus. Initial clinical suspicion was of metastatic ccRCC. However, tumour morphology and immunoprofile were distinct from the previous ccRCC and supported a diagnosis of primary microcystic adenoma. Analysis of DNA extracted from sinonasal tumour tissue did not show loss of the wild-type allele at the VHL locus. Although this did not support tumour association with VHL disease, it was not possible to look for a loss-of-function mutation. The association of primary microcystic adenoma of the sinonasal cavity with VHL disease remains speculative. These lesions are benign but are likely to require regular surveillance. Such tumours may require repeated surgical excision.

The Nrf2 transcription factor contributes to resistance to cisplatin in bladder cancer.

OBJECTIVES: Cisplatin is the key systemic chemotherapeutic agent used for bladder cancer, but chemoresistance is a major clinical problem. The transcription factor nuclear factor erythroid 2-related factor 2 (Nrf2) regulates various critical cellular processes, including cellular antioxidant response, cellular detoxification, and drug uptake/efflux. These processes, and the expression of multiple Nrf2 target genes, have been found to be associated with bladder cancer prognosis and chemotherapy resistance. We, therefore, investigated whether Nrf2 might regulate cisplatin resistance in bladder cancer. MATERIALS AND METHODS: We first used bladder cancer cell lines, including a cisplatin-resistant RT112 subline (RT112-CP), to investigate Nrf2 expression and activation and its association with cisplatin response. We then undertook immunohistochemical analysis of a tissue microarray of archival bladder cancer radical cystectomy specimens to test the relevance of clinical Nrf2 expression to outcomes following either neoadjuvant chemotherapy and cystectomy or cystectomy alone. RESULTS: Bladder cancer cell lines showed variable Nrf2 expression. Nrf2 expression was greater in RT112-CP cisplatin-resistant cells compared with that in parental RT112 cells. Nrf2 overexpression was functional in this model as it was associated with increased antioxidant response element reporter construct activity, Nrf2 target gene expression (metallothionein and glutathione reductase), and basal glutathione levels. Cisplatin resistance was associated with Nrf2 expression, and in RT112-CP cells, its depletion partially restored cisplatin sensitivity. We demonstrated increased cytoplasmic or nuclear Nrf2 expression or both in 32% of clinical bladder cancer samples compared with that in normal tissue samples. Expression of Nrf2 in bladder cancer following radical cystectomy was associated with unfavorable overall (median = 0.65 vs. 2.11 y, P = 0.045), bladder cancer-specific, and recurrence-free survival in those patients who also received neoadjuvant cisplatin-based chemotherapy but not in those treated with cystectomy alone. CONCLUSIONS: Nrf2 overexpression in bladder cancer is associated with clinically relevant cisplatin resistance that is reversible in experimental models and should now be tested in prospective studies.

Intraduct papillary mucinous neoplasm of the pancreas: a tumour linked with IgG4-related disease?

OBJECTIVES: Intraduct papillary mucinous neoplasm (IPMN) is a pancreatic tumour that is often associated with chronic pancreatitis (CP) in the surrounding pancreas. Type 1 autoimmune pancreatitis (AIP) is a fibro-inflammatory condition with characteristic histological features and prominent IgG4+ plasma cells and is part of the spectrum of IgG4-related disease (IgG4-RD). The aim of this study was to determine whether CP associated with pancreatic IPMN commonly represents AIP. METHODS: We identified two consecutive 'index' cases of pancreatic IPMN during routine reporting in which the adjacent pancreas showed morphological features suggestive of AIP. These cases were investigated using the Boston criteria for the histopathological diagnosis of IgG4-RD and the HISORt criteria for the clinical and histopathological diagnosis of AIP. Using the same criteria, we proceeded to a clinical review of 12 extra cases of IPMN in which the tumour or the surrounding pancreas showed significant lymphoplasmacytic inflammation and/or fibrosis. RESULTS: Both of the 'index' cases fulfilled the HISORt criteria for AIP and both had morphological features characteristic of IgG4-RD using the Boston criteria, although only one possessed features 'highly suggestive of IgG4-RD' after immunohistochemistry. Additionally, both 'index' cases had radiological features that could represent extrapancreatic manifestations. Review of the 12 additional cases of IPMN revealed no further examples showing co-existent AIP. CONCLUSION: While pancreatic IPMN and AIP may co-exist, most CP associated with IPMN does not represent AIP.