Succinate dehydrogenase (SDH)‐deficient renal cancer is a rare renal cancer subtype recently accepted by the World Health Organization as a unique subtype of renal cell carcinoma (RCC). Here we ...report a case of 17‐year‐old man. The detailed evaluation indicated occurrence of the SDHB‐deficient RCC. The genetic testing revealed no germline mutation in SDH genes. Immunohistochemistry showed SDHB deficiency, overexpression of pyruvate kinase M2 and dramatic downregulation of fructose‐1,6‐bisphosphatase metabolic enzymes, and unaltered levels of phosphorylated AMP‐activated protein kinase and mammalian target of rapamycin. Strong upregulation of INI1 and BRG1 and overexpression of BAF180, subunits of SWI/SNF ATP‐dependent chromatin remodeling complex, were also found. The identified tumor pathologically did not resemble clear cell renal cell carcinoma (ccRCC), but some metabolic alterations are common for both cancer types. Thus, we postulate that the phenotypical differences between ccRCC and SDHB‐deficient RCC may be related to distinct molecular and metabolic alterations.
Implications for Practice
Succinate dehydrogenase (SDH)‐deficient renal cell carcinoma (RCC) is a rare renal tumor occurring even in young patients. Until now, in all described and genetically tested cases, mutations and deletions in SDH genes have been found. This article describes SDHB‐deficient RCC without any germline mutations in SDH genes. Therefore, genetic analysis for germline mutations in SDH genes in SDH‐deficient RCC, especially in young individuals, should be strongly recommended, although as of now it is not obligatory. This knowledge will allow improvement of patient monitoring including both disease recurrence and new cancer appearance.
SDH‐deficient renal cell cancer is a rare renal tumor that can occur at a young age. This brief communication describes the case of a 17‐year‐old man.
Analysis of gene expression data suggests that breast cancers are divisible into molecular subtypes which have distinct clinical features. This study evaluates whether pathologic features and ...etiologic associations differ among molecular subtypes. We evaluated 804 women with invasive breast cancers and 2,502 controls participating in a Polish Breast Cancer Study. Immunohistochemical stains for estrogen receptor alpha, progesterone receptor, human epidermal growth factor receptors (HER2 and HER1), and cytokeratin 5 were used to classify cases into five molecular subtypes: luminal A, luminal B, HER2-expresing, basal-like, and unclassified. Relative risks were estimated using adjusted odds ratios and 95% confidence intervals. We observed that compared with the predominant luminal A tumors (69%), other subtypes were associated with unfavorable clinical features at diagnosis, especially HER2-expressing (8%) and basal-like (12%) tumors. Increasing body mass index significantly reduced the risk of luminal A tumors among premenopausal women (odds ratios, 0.71; 95% confidence intervals, 0.57-0.88 per five-unit increase), whereas it did not reduce risk for basal-like tumors (1.18; 0.86-1.64; P(heterogeneity) = 0.003). On the other hand, reduced risk associated with increasing age at menarche was stronger for basal-like (0.78; 0.68-0.89 per 2-year increase) than luminal A tumors (0.90; 0.95-1.08; P(heterogeneity) = 0.0009). Although family history increased risk for all subtypes (except for unclassified tumors), the magnitude of the relative risk was highest for basal-like tumors. Results from this study have shown that breast cancer risk factors may vary by molecular subtypes identified in expression studies, suggesting etiologic, in addition to clinical, heterogeneity of breast cancer.
Congenital cutaneous mastocytoma is an uncommon disorder characterized by abnormal proliferation of mast cells. It typically presents as a single, small, yellowish-brown plaque, and its diagnosis is ...generally facilitated by distinctive clinical features, including a positive Darrier's sign. This report presents a case of an unusually large, solitary congenital mastocytoma encompassing nearly the entire circumference of the calf, observed in a newborn boy of Bangladeshi origin. Measuring 13x6 cm, the lesion formed large bullae and subsequent erosions. The perplexing clinical appearance prompted a skin biopsy, revealing monomorphic CD117 (c-KIT) positive infiltration without significant cell pleomorphism, confirming the diagnosis of cutaneous mastocytoma. The patient underwent management with potent and very potent topical steroids, oral antihistamines, and non-adhesive dressings, remaining under long-term follow-up with secondary care dermatology. In reporting this case, our objective is to augment the existing scientific literature by providing additional evidence that cutaneous mastocytomas can display a spectrum of clinical presentations, as illustrated in this case.
Chronic rhinosinusitis (CRS) can be classified as eosinophilic (eCRS) or non-eosinophilic (neCRS) based on infiltration type. The SWI/SNF complex may be involved in the pathophysiology of CRS.
To ...assess the expression of the SWI/SNF complex in both CRS groups; to correlate blood eosinophil count (BEC), and histopathology eosinophil count (HPEC) with the SWI/SNF expression level in eCRS and neCRS.
The study population consisted of 96 patients (68 eCRS, 28 neCRS). Immunohistochemical staining was performed on sinonasal mucosa for assessment of SWI/SNF protein expression. Type of tissue infiltration was assessed in samples obtained from examined groups (HPEC). The diagnostic value of eCRS was 10 cells/HPF (high power field). Complete blood count was analysed in order to calculate BEC.
BEC and HPEC correlated negatively with all the SWI/SNF subunits. HPEC and BEC correlated positively with clinical findings (L-M and SNOT-22), while SWI/SNF correlated negatively with clinical findings (L-M and SNOT-22).
The SWI/SNF was observed in both eCRS and neCRS, with lower expression in former. The meaning of its negative correlation with BEC, HPEC and clinical findings in eCRS group remains to be understood.
Carcinogenesis involves altered cellular interaction and tissue morphology that partly arise from aberrant expression of cadherins. Mucin-like protocadherin is implicated in intercellular adhesion ...and its expression was found decreased in colorectal cancer (CRC). This study has compared MUPCDH (CDHR5) expression in three key types of colorectal tissue samples, for normal mucosa, adenoma, and carcinoma. A gradual decrease of mRNA levels and protein expression was observed in progressive stages of colorectal carcinogenesis which are consistent with reports of increasing MUPCDH 5′ promoter region DNA methylation. High MUPCDH methylation was also observed in HCT116 and SW480 CRC cell lines that revealed low gene expression levels compared to COLO205 and HT29 cell lines which lack DNA methylation at the MUPCDH locus. Furthermore, HCT116 and SW480 showed lower levels of RNA polymerase II and histone H3 lysine 4 trimethylation (H3K4me3) as well as higher levels of H3K27 trimethylation at the MUPCDH promoter. MUPCDH expression was however restored in HCT116 and SW480 cells in the presence of 5-Aza-2′-deoxycytidine (DNA methyltransferase inhibitor). Results indicate that μ-protocadherin downregulation occurs during early stages of tumourigenesis and progression into the adenoma-carcinoma sequence. Epigenetic mechanisms are involved in this silencing.
Abstract
Inflammatory dermatoses and inflammatory reaction patterns to underlying systemic disease are relatively uncommon in immunosuppressed organ transplant recipients (OTRs) and infection should ...always be suspected as a possible cause. We present an OTR with biopsy-proven panniculitis resulting from disseminated toxoplasmosis, only identified after extensive histological analysis. A 45-year-old Nigerian woman who was profoundly immunocompromised through a combination of a kidney transplant 12 months earlier, hyposplenism due to sickle cell anaemia and a CD4+ count 74 × 106 cells L–1 (> 455 × 106 L–1) presented with a 3-month history of > 20 painful, red–purple and hyperpigmented subcutaneous nodules and plaques up to 2 cm in diameter limited to her legs, associated with fatigue and weight loss. She only had childhood contact with cats. There was no lymphoedema or lymphadenopathy, and she was HIV negative. Urgent skin biopsy excluded Kaposi sarcoma and demonstrated a lobular, necrotizing panniculitis, a mixed inflammatory cell infiltrate and evidence of vasculitis. The cause was unclear; cultures for mycobacterial, fungal and bacterial infections were negative. However, on rereview of histology, within areas of inflammation and necrosis in the subcutaneous fat, there were a few scattered structures (10–30 μm in diameter) consisting of small basophilic periodic acid–Schiff-positive ‘dots’ within bright eosinophilic cytoplasm, raising the possibility of toxoplasmosis. Toxoplasma immunostaining was positive. Further tertiary review of histology and immunostaining by the Hospital for Tropical Diseases agreed that there was no other causative organism and the panniculitis and vasculitis were consistent with active toxoplasmosis. The diagnosis of toxoplasma reactivation was supported by positive toxoplasma IgG on pretransplant bloods. Magnetic resonance imaging of the head was consistent with cerebral toxoplasmosis. She received treatment with clindamycin, pyrimethamine and folinic acid and, thereafter, long-term cotrimoxazole prophylaxis. Cutaneous toxoplasmosis is rare, with only three reported cases over the last 10 years. Historically, a wide spectrum of clinical morphologies has been described, including maculopapular rashes, nodules, ulcers, dermatomyositis and even mimicry of varicella and graft-versus-host disease. Most cases affect immunocompromised patients. In our patient, this was the result of reactivation of latent infection, which is more common in West Africa, coinciding with profound immunosuppression. In our case, a diagnosis was only made after extensive histological review. Given the varied morphologies of clinical presentations, it is possible that this condition may be easily missed, with potentially serious consequences. In summary, we highlight the importance of maintaining a high index of suspicion for infection and the need for careful clinicopathological correlation in OTRs presenting with apparently atypical inflammatory skin lesions.
Abstract
Ultraviolet radiation (UVR) is the most common environmental carcinogen to cause cutaneous squamous cell carcinoma (cSCC). However, other carcinogens may also play a role and should be ...suspected when cSCC occurs in people with skin of colour (SOC) in whom ultraviolet (UV)-induced cSCC is less common. We present the case of a South Asian female who presented with an aggressive cSCC, which we hypothesize was related to previous arsenic exposure. A 70-year-old Bangladeshi woman (skin phototype V) presented with a 4-cm diameter, tender, keratotic plaque at the base of her left thumb, which had been present for 12 years and was slowly enlarging. There was no associated lymphadenopathy. She also had multiple palmoplantar keratotic papules and two hyperkeratotic plaques in UV-protected areas on her trunk. Histology of the lesion on her thumb confirmed a cSCC with high-risk features: poorly differentiated, invasion 9.5 mm into fibromuscular tissue, perineural invasion (nerve diameter > 0.1 mm) and vascular invasion. The truncal plaques were confirmed to be SCC in situ. The cSCC was incompletely excised and subsequently showed extensive involvement of periosteal soft tissues with invasion into bone marrow. Staging computed tomography showed no evidence of nodal or distant metastatic disease. She subsequently underwent ray amputation and remains under close clinical surveillance. Given the cSCC location and her skin phototype, potential non-UV radiation (UVR) causes were explored. In view of the palmoplantar keratotic papules and SCC in situ, chronic arsenic exposure was suspected. Further questioning revealed a history of drinking well water in a rural village in Bangladesh throughout childhood and early adulthood, although exposure had stopped > 40 years ago. Arsenic exposure from contaminated groundwater was therefore considered to be the most likely diagnosis. She was started on long-term chemoprevention with acitretin. Arsenic is a potent human carcinogen and a well-recognized cause of cSCC; the latency period may be 30–40 years. Most cases are likely to be in people exposed through environmental arsenic exposure, such as contaminated groundwater, with some cases of exposure to arsenic-containing traditional medicines also reported. Carcinogenic mechanisms are uncertain but may involve dysregulation of the Hippo signalling pathway. In summary, although the incidence of UVR-related cSCC is lower, this case highlights the importance of considering risk factors, other than UVR, in cSCC arising in people with SOC. Identifying relevant carcinogens may require a detailed travel, social and cultural history and, more importantly, an awareness of the non-UVR causes of cSCC.
Epithelial tissues achieve a highly organized structure due to cell-cell junction complexes. Carcinogenesis is accompanied by changes in cell interactions and tissue morphology, which appear in the ...early stages of benign tumors and progress along with invasive potential. The aim of the present study was to analyze the changes in expression levels of genes encoding intercellular junction proteins that have been previously identified to be differentially expressed in colorectal tumors compared with normal mucosa samples (fold change, >2.5) in genome-wide expression profiling. The expression of 20 selected genes was assessed using quantitative reverse transcription polymerase chain reaction in 26 colorectal cancer, 42 adenoma and 24 normal mucosa samples. Between these tissue types, differences were observed in the mRNA levels of genes encoding adherens junction proteins (upregulation of CDH3 and CDH11, and downregulation of CDH19 and PTPRF), tight junction proteins (upregulation of CLDN1 and CLDN2, and downregulation of CLDN5, CLDN8, CLDN23, CLDN15, JAM2 and CGN) and desmosomes (upregulation of DSC3 and DSG3, and downregulation of DSC2), in addition to a decrease in the expression of certain other genes involved in intercellular connections: PCDHB14, PCDH7, MUPCDH and NEO1. The differences between tissue types were statistically significant, and separate clustering of normal adenoma and carcinoma samples was observed in a hierarchical clustering analysis. These results indicate that the morphological changes in neoplastic colon tissue that occur during the 'adenoma-carcinoma sequence' are accompanied by specific changes in the expression of multiple genes encoding the majority of cell-cell junction complexes. The particular differential expression patterns appear to be consistent among patients with cancer and adenoma, in addition to normal mucosa samples.
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