GLI1 -Rearranged Enteric Tumor : Expanding the Spectrum of Gastrointestinal Neoplasms With GLI1 Gene Fusions.

GLI1 encodes a transcription factor that targets cell cycle regulators affecting stem cell proliferation. GLI1 gene fusions were initially described in pericytomas with a t[7;12] translocation and more recently in gastric plexiform fibromyxomas and gastroblastomas. This study describes the clinicopathologic, immunohistochemical, and molecular features of three intestinal-based neoplasms harboring GLI1 gene fusions. We studied three unique mesenchymal small bowel tumors. Paraffin embedded tumor tissues from these cases and 62 additional tumor samples that included a plexiform fibromyxoma were sequenced using a targeted RNAseq method to detect fusion events. The study patients included two women and one man who were 52, 80, and 22 years of age at the time of diagnosis. The tumors involved the submucosa and muscularis propria of the duodenum, jejunum, and ileum. All 3 tumors contained a proliferation of monotonous oval or spindle cells with scattered, somewhat dilated vessels. Two cases showed epithelioid structures such as glands, tubules, or nests. Immunohistochemical analysis revealed cytokeratin expression in the epithelioid components of both tumors displaying these features, and variable numbers of mesenchymal cells. Diffuse CD56 positivity was seen in the mesenchymal component of 2 tumors and desmin and smooth muscle actin staining in the other tumor. Immunostains for S-100 protein, DOG-1, and CD117 were negative in all cases. GLI1 fusions with different partner genes were detected in all tumors, and in the plexiform fibromyxoma, used as a control. Validation by fluorescence in situ hybridization was performed. None of the tumors have recurred or metastasize after surgery. We describe novel GLI1 fusions in 3 mesenchymal neoplasms of the small intestine, including 2 with biphenotypic features. Thus far, all cases have pursued indolent clinical courses. We propose the term " GLI1 -rearranged enteric tumor" to encompass this group of unique neoplasms of the small intestine that harbor GLI1 gene fusions and expand the spectrum of gastrointestinal neoplasms with these alterations.

Dysdiadochokinesia, Ataxia, and Anemia: A Sign of Intraluminal Malignant Mesothelioma?

An 87-year-old man presented with altered mental status and ataxia was found to have a neuron-restricted antibody in his cerebrospinal fluid, concerning for a paraneoplastic syndrome of unknown origin. He also exhibited anemia, but otherwise normal electrolytes and liver chemistries. He underwent positron emission tomography/computed tomography which revealed abdominal lymphenopathy. He then underwent push enteroscopy and was found to have a jejunal mass, biopsy proven to be malignant mesothelioma. Malignant mesothelioma is 4-5 times more prevalent in men than women. It is limited to the small bowel, and paraneoplastic syndromes are extremely rare and carry a poor prognosis. The presence of anemia with cerebellar symptoms should trigger a search for a paraneoplastic syndrome-related malignancy.

Rare Histological Variants of Liver Cancer and Their Management: A Single-Institution Experience.

Primary liver malignancies, including hepatocellular carcinoma (HCC) and cholangiocarcinoma, are a major cause of cancer-related morbidity and mortality worldwide. There are several histologically and biologically distinct subtypes of liver cancer that have previously been reported. However, literature regarding the nonsurgical management of these patients upon disease recurrence remains limited. These variants include combined HCC-cholangiocarcinoma (cHCC-CC), Epstein-Barr virus- (EBV-) associated carcinoma, undifferentiated carcinoma, and clear cell or thyroid-like variants of HCC. Here, we aim to highlight the pathologic features, clinical course, and outcomes of five patients with these unusual hepatic tumors and explain the rationale behind the choice of their systemic therapies upon disease recurrence. All patients underwent surgical resection as the standard of care for localized disease, and upon relapse, they were treated with either chemotherapy, targeted therapy, immunotherapy, or active surveillance based on the clinical context and tumor histology. These rare variants are important to recognize as they have prognostic and therapeutic implications, and there are currently insufficient data in the literature to guide further therapy.

Thyroid-Like Cholangiocarcinoma: Histopathological, Immunohistochemical, In-Situ Hybridization and Molecular Studies on an Uncommon Emerging Entity.

Thyroid-like cholangiocarcinoma is a very uncommon variant of peripheral-type cholangiocarcinoma. To date, only 4 prior cases have been reported. The molecular features of this tumor have not been described. We report a case of a 60-year-old woman with a tumor that evolved over a period of 10 years. A left hepatectomy specimen showed an 11 cm tumor that on histology exhibited areas reminiscent of a thyroid tumor with follicular and insular features which were positive on immunohistochemistry for cytokeratin 7 and in-situ hybridization for albumin. A detailed molecular analysis failed to show mutations common to cholangiocarcinomas but revealed frameshift mutations in 2 chromatin-remodeling genes, CREBBP and KMNT2A. This case confirms that thyroid-like cholangiocarcinoma is a histologic variant of this tumor that is associated with relatively low growth. As most cholangiocarcinomas, it is diffusely positive for cytokeratin 7 and albumin by in-situ hybridization. Given its rarity, the molecular alterations in this specific histologic subtype remain to be fully elucidated.

Characterization of Novel Injectable Lifting Agents Used in Colonic Polyp Removal: An Emerging Amyloid Mimic.

Colon polypectomy can require an injection of a submucosal lifting agent to fully visualize and completely remove the polyp. To the best of our knowledge, this is the largest morphologic series on the novel lifting agents Eleview and Orise. The study consisted of 1 polypectomy and 8 colon resections from 9 patients: 6 women, 3 men (mean age=64 y); Orise=6, Eleview=3; the median time interval between injection and resection=16 weeks. Pathologic diagnoses of the polyps included tubular adenoma (n=4), tubulovillous adenoma (n=4), and sessile serrated adenoma/polyp (n=1). We report that a histologically processed Orise aliquot from the manufacturer showed similar histology to that seen in the specimens from patients with confirmed Orise injection. The morphology of the agents in the patient specimens changed with time status postinjection: immediate resection of the lifting agent showed basophilic, amorphous, and bubbly-extracellular material with prominent hemorrhage, and resection ∼3 months after lifting agent injection showed prominent hyalinized, pink-amorphous ribbons and globules with a foreign body giant cell reaction and fibrosis. The epicenter of the lifting agents was in the submucosa, and the agents were neither refractile nor polarizable. Because of the morphologic overlap with amyloid, 5 cases were stained with Congo Red, and all cases were negative. In conclusion, awareness of the morphology of these new lifting agents is important for accurate diagnosis and to avoid the diagnostic pitfall of amyloid. These lesions can be definitively distinguished from amyloid by their nonreactivity on a Congo Red and familiarity with their characteristic clinicopathologic presentation.

SOX10 expression in mammary invasive ductal carcinomas and benign breast tissue.

SOX10 immunohistochemistry is used to identify tumors of neural crest origin, including melanocytic neoplasms. SOX10 expression has also been identified in myoepithelial cells of the breast and in a subset of invasive mammary carcinomas. In order to characterize SOX10 expression in ductal carcinomas of the breast, the aim of this study was to characterize the SOX10 in invasive ductal carcinomas according to molecular subtype, DCIS, and benign breast tissue. Forty cases of invasive ductal carcinoma of the breast were retrieved, with ten cases with immunohistochemical profile compatible with luminal A-like, luminal B-HER2-positive, non-luminal HER2-positive, and triple-negative subtypes. Whole tissue sections from each case were stained with SOX10. Six (60%) of ten triple-negative tumors were SOX10+ compared with 1 (3%) of 30 carcinomas of other molecular subtypes. All but one of the positive tumors showed at least moderate expression in at least 40% of tumor cells. All seven cases SOX10+ carcinomas were grade 3 tumors. Of the 13 cases with DCIS available for assessment, one (8%) showed positive SOX10 expression (a case associated with triple-negative carcinoma). Twenty-two cases contained normal breast tissue that showed SOX10 expression in both myoepithelial and luminal cells, predominantly patchy with variable intensity. SOX10 showed incomplete myoepithelial staining compared to other myoepithelial markers. In conclusion, SOX10 IHC cannot reliably differentiate between high-grade triple-negative carcinomas, melanomas, and myoepithelial tumors in the breast. SOX10 is not as robust a myoepithelial marker compared with other established markers.

DALM, rest in peace: a pathologist's perspective on dysplasia in inflammatory bowel disease in the post-DALM era.

There are few abbreviations in surgical pathology that are associated with as much immediate recognition, frustration, and confusion as DALM (dysplasia-associated lesion or mass). DALM is used to describe endoscopically visible dysplastic lesions in the surveillance of patients with inflammatory bowel disease. However, the diagnosis of DALM has been complicated by the inconsistent criteria and use of terminology for describing dysplasia in inflammatory bowel disease, and a tendency to relate DALM with the need for colectomy. Fortunately, advancements in both endoscopic visualization and local excision capability have allowed for a more defined management of dysplasia in inflammatory bowel disease. In 2015, the Surveillance for Colorectal Endoscopic Neoplasia Detection and Management in Inflammatory Bowel Disease Patients International Consensus Recommendations (SCENIC) Development Panel, a panel of predominantly expert gastroenterologists and endoscopists in surveillance of inflammatory bowel disease, published a consensus statement. One recommendation was to abandon DALM-related terminology in favor of endoscopic descriptors modified from the Paris endoscopic classification. Recommendations on surveillance and management of dysplastic lesions were also provided. Nevertheless, interval carcinomas and metachronous neoplasia remain persistent issues. This review aims to provide an update on the post-DALM terminology and management recommendations for inflammatory bowel disease-associated dysplasia necessary for a meaningful communication between pathologists and clinicians.

Glypican-1 immunohistochemistry does not separate mesothelioma from pulmonary adenocarcinoma.

Immunohistochemistry (IHC) is used to help differentiate pleural mesothelioma from pulmonary adenocarcinoma in pleural biopsies and cytology specimens of pleural effusions due to overlapping morphologic features between these two malignancies. The aim of this study is to evaluate IHC glypican-1, a recently proposed marker for epithelioid mesothelioma, in our cohort of mesotheliomas and pulmonary adenocarcinoma. Tissue microarrays with duplicate cores from 33 cases of mesotheliomas (28 epithelioid type and five sarcomatoid type) and 21 cases of pulmonary adenocarcinoma were stained with glypican-1 antibody. The proportion of cases by tumor type showing staining with glypican-1 and the H-score for each tumor type were evaluated. All 33 cases of mesothelioma and all 20 cases of pulmonary adenocarcinoma with interpretable cores showed positive cytoplasmic staining. All but one case of mesothelioma and all pulmonary adenocarcinomas showed staining in at least 80% of the tumor cells. The mean H-score for glypican-1 of mesothelioma (134 ± 59, mean ± SD) was not significantly different from that for pulmonary adenocarcinoma (156 ± 60; P = 0.21). Neither epithelioid type (mean H-score 135 ± 57) nor sarcomatoid type (mean H-score 130 ± 78) of mesothelioma showed different H-scores when compared to pulmonary adenocarcinoma (P = 0.23 and 0.42, respectively). In conclusion, glypican-1 IHC does not differentiate mesothelioma from pulmonary adenocarcinoma.

Detection and genomic characterization of a mammary-like adenocarcinoma.

Whole-genome and transcriptome sequencing were performed to identify potential therapeutic strategies in the absence of viable treatment options for a patient initially diagnosed with vulvar adenocarcinoma. Genomic events were prioritized by comparison against variant distributions in the TCGA pan-cancer data set and complemented with detailed transcriptome sequencing and copy-number analysis. These findings were considered against published scientific literature in order to evaluate the functional effects of potentially relevant genomic events. Analysis of the transcriptome against a background of 27 TCGA cancer types led to reclassification of the tumor as a primary HER2+ mammary-like adenocarcinoma of the vulva. This revised diagnosis was subsequently confirmed by follow-up immunohistochemistry for a mammary-like adenocarcinoma. The patient was treated with chemotherapy and targeted therapies for HER2+ breast cancer. The detailed pathology and genomic findings of this case are presented herein.

Large and Small Airway Disease Related to Inflammatory Bowel Disease.

Although airway disease associated with inflammatory bowel disease is uncommon, its involvement may have severe clinical consequences. This article reviews the breadth of pathologic processes that can be expected in the various sizes of airways, and provides a differential diagnosis from other airway diseases that can be found in association with inflammatory bowel disease. It also makes suggestions as to how airway disease can be best differentiated by using appropriate special stains.

Predictors of suboptimal and crash initiation of dialysis at two tertiary care centers.

Many end-stage renal disease patients do not have an optimal start to dialysis. Many patients have suboptimal initiation, while others "crash" start on dialysis without prior care from a nephrologist. We examined factors associated with suboptimal or crash starts. We conducted a retrospective cohort study of 377 incident dialysis patients at two tertiary care centers from January 2006 to April 2011. Logistic regression was used to identify factors associated with suboptimal and crash starts to dialysis. Out of 377 patients, 102 (27%) had optimal starts, 221 (59%) had suboptimal starts, and 54 (14%) had crash starts. Three hundred thirty-four patients (89%) began with hemodialysis, while 11% started with peritoneal dialysis. Factors independently associated with a suboptimal start as opposed to an optimal start included nephrology care more than 12 months prior to initiation of dialysis (odds ratio [OR], 0.26; 95% confidence interval [CI], 0.12-0.58), Charlson Comorbidity Index (OR, 1.25 per 1 point; 95% CI, 1.09-1.43), and age (OR, 1.02 per 1 year; 95% CI, 1.00-1.04). In comparison, diabetic nephropathy (OR, 0.25; 95% CI, 0.12-0.54), a history of pulmonary edema within 6 months prior to initiation of dialysis (OR, 3.70; 95% CI, 1.77-7.75), and a diagnosis of chronic obstructive lung disease (OR, 0.07; 95% CI, 0.01-0.52) were independently associated with a crash start. There was a low incidence of optimal dialysis starts in our tertiary care dialysis population. Our study highlights that suboptimal and crash start patients are distinct populations. Modifying factors that predict nonoptimal dialysis starts will need to consider these distinctions.