Some Morphology Frontiers of Dysplasia in the Tubular Gastrointestinal Tract: The Rodger C. Haggitt Memorial Lecture.

This review, based on the content of the 2020 US Gastrointestinal Pathology Society's Rodger Haggitt Lecture, concerns an array of tubular gastrointestinal tract dysplastic or possible "predysplastic lesions" with an almost purely morphologic focus based on our collaborative efforts over the past few years. These processes include esophageal epidermoid metaplasia, Barrett esophagus-associated dysplasia, polypoid gastric dysplastic lesions, small intestinal dysplasia, and the ability of metastases to mimic it, the controversial "serrated epithelial change" encountered in the setting of long-standing ulcerative and Crohn colitis, and recently described anal columnar human papilloma virus-associated neoplasms.

Exogenous copper exposure causing clinical wilson disease in a patient with copper deficiency.

BACKGROUND: Human Swayback is a disease characterized by acquired copper deficiency which primarily manifests as myeloneuropathy. Common causes include malabsorptive disorders, gastric surgery, total parenteral nutrition and excessive zinc intake. In contrast, copper supplementation should be closely monitored as excessive doses can lead to acute intoxication and in chronic cases, cirrhosis. Copper derangements are rare, however it is important to consider them due to potential severe complications. CASE PRESENTATION: We present a middle-aged man who had been previously diagnosed with Human Swayback after presenting with various neurological symptoms. The patient was subsequently placed on copper supplementation. A decade later, he was referred to our hospital for liver transplant evaluation due to new diagnosis of decompensated end-stage liver disease after an abdominal surgery. His initial workup was suggestive of Wilson disease-subsequent ATP7B gene was negative. Ultimately, the patient underwent liver transplantation; liver explant was significant for a copper dry weight concentration of 5436 mcg/g. CONCLUSIONS: Human Swayback is a very rare copper-related disease which deserves awareness due to its potential irreversible health effects in the human body. Additionally, in patients who require copper supplementation, serial levels should be monitored to ensure adequate copper levels.

RNA-Seq Reveals Differences in Expressed Tumor Mutation Burden in Colorectal and Endometrial Cancers with and without Defective DNA-Mismatch Repair.

Tumor mutation burden (TMB) is an emerging biomarker of immunotherapy response. RNA sequencing in FFPE tissue samples was used for determining TMB in microsatellite-stable (MSS) and microsatellite instability-high (MSI-H) tumors in patients with colorectal or endometrial cancer. Tissue from tumors and paired normal tissue from 46 MSI-H and 12 MSS cases were included. Of the MSI-H tumors, 29 had defective DNA mismatch-repair mutations, and 17 had MLH1 promoter hypermethylation. TMB was measured using the expressed somatic nucleotide variants (eTMB). A method of accurate measurement of eTMB was developed that removes FFPE-derived artifacts by leveraging mutation signatures. There was a significant difference in the median eTMB values observed between MSI-H and MSS cases: 27.3 versus 6.7 mutations/megabase (mut/Mb) (P = 3.5 × 10-9). Among tumors with defective DNA-mismatch repair, those with mismatch-repair mutations had a significantly higher median eTMB than those with hypermethylation: 28.1 versus 17.5 mut/Mb (P = 0.037). Multivariate analysis showed that MSI status, tumor type (endometrial or colorectal), and age were significantly associated with eTMB. Additionally, using whole-exome sequencing in a subset of these patients, it was determined that DNA TMB correlated well with eTMB (Spearman correlation coefficient, 0.83). These results demonstrate that RNA sequencing can be used for measuring eTMB in FFPE tumor specimens.

Eosinophilic esophagitis: imaging features with endoscopic and pathologic correlation.

OBJECTIVE: We aim to review the imaging features of eosinophilic esophagitis on fluoroscopy and present how they can correlate with endoscopic and pathologic findings. RESULTS: Eosinophilic esophagitis is a chronic immune-mediated disease that results in esophageal dysfunction. Upper esophagogastroduodenoscopy is high yield and required for biopsies to demonstrate the hallmark histologic findings of eosinophil-predominant inflammation. While esophagogastroduodenoscopy is currently mandatory for diagnosis, imaging findings can provide valuable information regarding the structural and functional properties of the esophagus. In addition, fluoroscopic studies may be very helpful in the setting of subtle findings and to evaluate fibrotic remodeling changes. CONCLUSION: Radiologic examinations are a valuable tool in the assessment of eosinophilic esophagitis and can highlight changes of fibrostenotic disease, as overall narrowing can be more conspicuous fluoroscopically than endoscopically. As the disease increases in prevalence, it is critical that physicians recognize this condition and facilitate diagnosis and treatment.

Local excision for patients with stage I anal canal squamous cell carcinoma can be curative.

BACKGROUND: Definitive concurrent chemoradiation is the current standard of care for all stage I anal canal squamous cell carcinoma. Local excision as primary treatment for selected stage I lesions has been reported in the literature but is not currently recommended by major guidelines. We herein compared the oncologic outcomes of patients with stage I anal canal squamous cell carcinoma treated with local excision alone versus chemoradiation to determine if there are any significant differences in outcomes including disease free survival, overall survival (OS) and local failure rate. METHODS: A retrospective review of all patients treated for stage I anal canal squamous cell carcinoma between 1990 and 2016 was conducted. Data collected included baseline demographics, staging studies, pathology, treatment received, relapse pattern and survival. RESULTS: A total of 57 patients were treated for stage I anal canal squamous cell carcinoma between 1990 and 2016; 13 were treated with local excision alone and 44 were treated with chemoradiation therapy. Baseline characteristics in both cohorts of patients were comparable. Median follow-up duration of the local excision and the chemoradiation cohorts were 106 and 70 months, respectively. Of the 13 patients in local excision cohort, two patients had disease recurrence, at 21 and 97 months from the diagnosis. Both patients were long term survivors with salvage treatment. In chemoradiation cohort, 1 out of 44 patients had a local recurrence at 1 year who underwent curative resection. Five-year progression free survival (PFS) of subjects in local excision cohort and chemoradiation cohort were 91% and 83%, respectively (P=0.57). CONCLUSIONS: Local excision as primary treatment may be safe and effective for a selected group of stage I anal canal squamous cell carcinoma patients.

Identification of key challenges in liver pathology: data from a multicenter study of extramural consults.

Extramural consultation for challenging pathology cases is an important part of patient care. The specific reasons why liver cases are submitted in consultation are poorly understood. To study patterns in extramural consultation, data were gathered from 1360 liver/GI/pancreatobiliary consults submitted to 7 academic centers. Liver cases comprised 40% of consults and are the focus of this paper. They were submitted for questions on medical (61%) and tumor pathology (39%). A preliminary diagnosis was provided by the referring pathologist in 65% of cases. The most common questions in medical liver pathology were on general classification of a hepatitic pattern of injury (37%), primary biliary cirrhosis (14%), fatty liver disease (13%), autoimmune hepatitis (12%), and etiology of cirrhosis (10%). Most tumor consults were submitted for classification (83%). The most common final tumor consultant diagnoses for benign tumors were hepatic adenoma or focal nodular hyperplasia (52%) and for malignant tumors were metastatic malignancies (47%), hepatocellular carcinoma (32%), or cholangiocarcinoma (8%). For cases submitted with a diagnosis of malignancy, the diagnosis was concordant (43% of cases), concordant but with a generic diagnosis for which a more specific diagnosis could be rendered (37%), or discordant with a major change in diagnosis from malignant to benign or change in tumor type (17%). In conclusion, analysis of consult patterns identifies challenging areas in medical and tumor liver pathology, areas that benefit from consult services and can be focused on by continuing medical educational activities.

Knowledge gaps in the appendix: a multi-institutional study from seven academic centers.

Appendix pathology represents uncommonly encountered specimens with unique diagnostic challenges. To delineate common knowledge gaps, extramural consults submitted to seven institutions between 2016-2017 were reviewed. All appendix consults were resections (100%, n = 43), and the majority were directed for consultation by the originating pathologist (95%, n = 41) with no additional studies performed by the consultant (65%, n = 28). This study was dominated by inquiries related to low grade appendiceal mucinous neoplasms (44%, n = 19) and goblet cell carcinoid related neoplasms (19%, n = 8). Of the 43 appendiceal consults, 19 were submitted by the contributing pathologist as low grade appendiceal mucinous neoplasm, but only half of these were diagnosed by the consultant as such (n = 9). Low grade appendiceal mucinous neoplasm-related consultation themes included diverticular disease, criteria for invasion, high grade atypia, extra-appendiceal mucin, and staging. Examples of major disagreements that were downgraded included consults submitted as low grade appendiceal mucinous neoplasm and diagnosed by the consultant as serrated polyp (n = 3), appendicitis (n = 1), and benign appendix (n = 1). Examples of major disagreements-upgraded included cases submitted as low grade appendiceal mucinous neoplasm and diagnosed by the consultant as low grade appendiceal mucinous neoplasm with high-risk features (n = 2) and mucinous adenocarcinoma (n = 2). One case contained both a major disagreement-upgrade (low grade appendiceal mucinous neoplasm changed to high grade appendiceal mucinous neoplasm) and a major disagreement-downgrade (pT3 changed to Tis). Of the 15 cases diagnosed by the consultants as low grade appendiceal mucinous neoplasm, submitted diagnoses included low grade appendiceal mucinous neoplasm (n = 9), adenocarcinoma (n = 5), and one case was submitted without a diagnosis. For goblet cell carcinoid-related consults, the usual inquiry related to distinguishing goblet cell carcinoid from goblet cell carcinoid with adenocarcinoma (adenocarcinoma ex-goblet cell carcinoid). Of the 38 overall consults with a submitted diagnosis, 53% (n = 20) were disagreements, and most of these were major disagreements-downgraded (n = 13).

Intestinal metaplasia of the gastric cardia: findings in patients with versus without Barrett's esophagus.

BACKGROUND AND AIMS: There is controversy about finding intestinal metaplasia (IM) of the gastric cardia on biopsy. The most recent American College of Gastroenterology guideline comments that IM cardia is not more common in patients with Barrett's esophagus (BE). It provides limited guidance on whether the cardia should be treated when patients with BE undergo endoscopic eradication therapy (EET) and whether the cardia should undergo biopsy after ablation. The aims of our study were to determine the frequency in the proximal stomach of (1) histologic gastric cardia mucosa and (2) IM cardia. A third aim was to explore the frequency of advanced pathology (dysplasia and adenocarcinoma) in the cardia after patients with BE have undergone EET. METHODS: Consecutive patients undergoing esophagogastroduodenoscopy between January 2008 and December 2014 who had proximal stomach biopsies were included. Patients who had histologically confirmed BE were compared with those without BE. RESULTS: Four hundred sixty-two patients, 289 with BE and 173 without BE, were included. Histologically confirmed cardiac mucosa was found in 81.6% of all patients. This was more frequent in those with versus without BE (86% vs 75%; odds ratio [OR], 2.06; 95% confidence interval [CI], 1.28-3.32; P = .003). IM cardia was more common in the BE group (17% vs 7%; OR, 2.67; 95% CI, 1.38-5.19; P = .004). Advanced pathology was more likely in the patients with BE who had undergone EET. CONCLUSIONS: Cardiac mucosa is present in most patients who undergo endoscopy for upper GI symptoms. IM cardia is more common in patients with BE than those without. Advanced histologic changes in the cardia were seen only in the subgroup of patients with BE who had undergone EET.

Treponema pallidum Immunohistochemistry is positive in human intestinal Spirochetosis.

BACKGROUND: Human intestinal spirochetosis (IS) has been recognized for decades, but whether it represents commensalism or a pathogenic process remains controversial. IS is diagnosed on routine stains with confirmation by silver stains but these stains are labor intensive and slow to read. We evaluated the Treponema pallidum immunostain as a diagnostic adjunct for IS. METHODS: We retrieved biopsies from 33 patients with IS for this study. Each case was tested by Warthin-Starry (WS) and T. pallidum immunohistochemistry (IHC). Species specific genotyping was performed in 3 cases. RESULTS: Patients with IS ranged from 22 to 82 years without gender predilection. IS involved normal (n = 15), and inflamed (n = 5) mucosa and colonic polyps (n = 13). Warthin-Starry and T. pallidum IHC were positive in all cases including both species of Brachyspira. Six (18%) symptomatic patients were treated for IS, and experienced resolution. In patients diagnosed with incidental IS on cancer screening (n = 5), follow up biopsies, without therapy, were negative for IS. T. pallidum IHC required 75 min less hands-on time than WS for performance and was faster to interpret. CONCLUSIONS: T. pallidum IHC can be used to confirm the diagnosis of IS and is easier to perform and faster to interpret than WS.

Undifferentiated Pancreatic Carcinomas Display Enrichment for Frequency and Extent of PD-L1 Expression by Tumor Cells.

OBJECTIVES: Programmed death ligand 1 (PD-L1) expression in pancreatic ductal adenocarcinoma (PDA) has been described, but unselected PDAs have shown limited clinical responsiveness to anti-programmed death 1 (PD-1)/PD-L1 therapy. METHODS: We studied 24 cases of undifferentiated pancreatic carcinoma (UPC) using immunohistochemistry for PD-L1 (E1L3N clone), CD3, CD20, CD68, and DNA mismatch repair proteins in this study. Slides were scored for extent of PD-L1 expression on tumor cells and tumor-infiltrating immune cells. RESULTS: PD-L1 expression was more frequent in UPCs than in PDAs (63% vs 15%, P < .01). The extent of PD-L1 expression was greater in UPCs, with 13 (87%) of 15 cases containing 10% or more positive tumor cells compared with three of seven PDAs (P = .05). Both tumor groups showed similar numbers of tumor-infiltrating T cells, B cells, and macrophages. CONCLUSIONS: UPC is enriched for PD-L1 expression in frequency and extent, relative to conventional PDA. Anti-PD-1/PD-L1 agents may represent a valuable therapeutic approach for this subset of highly aggressive pancreatic carcinoma.

Targeted next-generation sequencing supports epidermoid metaplasia of the esophagus as a precursor to esophageal squamous neoplasia.

Esophageal epidermoid metaplasia is a rare condition that involves the proximal-to-middle third of the esophagus. It is sharply demarcated and defined histologically by epithelial hyperplasia, a prominent granular cell layer, and superficial hyperorthokeratosis. In addition, preliminary studies have suggested an association between esophageal epidermoid metaplasia and esophageal squamous neoplasia (squamous dysplasia and esophageal squamous cell carcinoma). To further characterize esophageal epidermoid metaplasia and better define its relationship to squamous neoplasia of the esophagus, we performed targeted next-generation sequencing on uninvolved esophageal squamous mucosa and matching esophageal epidermoid metaplasia specimens from 18 patients. Further, we evaluated both synchronous and metachronous high-grade squamous dysplasia/esophageal squamous cell carcinoma by next-generation sequencing from 5 of the 18 (28%) patients, and compared these findings to corresponding esophageal epidermoid metaplasia specimens. Targeted next-generation sequencing revealed 12 of 18 (67%) esophageal epidermoid metaplasia specimens' harbored alterations in genes often associated with esophageal squamous cell carcinoma. The most frequently mutated genes consisted of TP53 (n=10), PIK3CA (n=2), EGFR (n=2), MYCN (n=1), HRAS (n=1), and the TERT promoter (n=1). Sequencing of synchronous and metachronous high-grade squamous dysplasia/esophageal squamous cell carcinoma identified shared genetic alterations with corresponding esophageal epidermoid metaplasia specimens that suggests a clonal relationship between these entities. In addition, the presence of a TP53 mutation in esophageal epidermoid metaplasia specimens correlated with concurrent or progression to high-grade squamous dysplasia/esophageal squamous cell carcinoma. No genetic alterations were detected in uninvolved esophageal squamous mucosa. On the basis of these findings, we conclude esophageal epidermoid metaplasia is a precursor to in situ and invasive esophageal squamous neoplasia. Further, the detection of TP53 mutations in esophageal epidermoid metaplasia specimens may serve as an early detection biomarker for high-grade squamous dysplasia/esophageal squamous cell carcinoma.

Challenges to "Classic" Esophageal Candidiasis: Looks Are Usually Deceiving.

Objectives: We undertook the first case control study of histologically confirmed esophageal candidiasis (EC). Methods: A computer search from July 2012 through February 2015 identified 1,011 esophageal specimens, including 40 cases of EC and 20 controls. Results: The EC incidence was 5.2%; it was associated with immunosuppression and endoscopic white plaques and breaks. Smoking was a predisposing factor, and alcohol was protective. EC had no unique symptoms, and 54% of endoscopic reports did not suspect EC. Important histologic clues included superficial and detached fragments of desquamated and hyper-pink parakeratosis, acute inflammation, intraepithelial lymphocytosis, dead keratinocytes, and bacterial overgrowth. Thirty percent had no neutrophilic infiltrate. Pseudohyphae were seen on H&E in 92.5% (n = 37/40). "Upfront" periodic acid-Schiff with diastase (PAS/D) on all esophageal specimens would have generated $68,333.49 in patient charges. Our targeted PAS/D strategy resulted in $13,044.87 in patient charges (cost saving = 80.9%, $55,288.62). Conclusions: We describe the typical morphology of EC and recommend limiting PAS/D to cases where the organisms are not readily identifiable on H&E and with at least one of the following: (1) ulcer, (2) suspicious morphology, and/or (3) clinical impression of EC.

Hepatoid Carcinoma of the Pancreas: Case Report, Next-Generation Tumor Profiling, and Literature Review.

Fewer than 25 cases of hepatoid carcinoma of the pancreas have been reported in the literature. We present a case in a 61-year-old male with a remote history of Hodgkin's lymphoma and gastric neuroendocrine cell hyperplasia. On surveillance endoscopic ultrasound, an 8 × 5 mm cystic lesion was seen in the tail of the pancreas. MRI showed a focal pancreatic duct cut-off with mild ductal dilation. Fine needle aspiration was performed, which was concerning for acinar cell carcinoma. The patient underwent distal pancreatectomy and recovered uneventfully. Final pathology demonstrated a 1.3-cm hepatoid carcinoma of the pancreas, with a final clinicopathological stage of T1N0M0. Next-generation nucleic acid sequencing of the tumor did not suggest a viable adjuvant chemotherapeutic agent, and no adjuvant therapy was administered. The patient has no evidence of disease 6 months following resection. A further characterization and description of the outcomes of these rare tumors is warranted to help guide providers and counsel patients.

An Unusual Suspect: Lymphoepithelial Cyst of the Pancreas.

Lymphoepithelial cysts (LECs) of the pancreas are benign, rare pancreatic cysts that are found predominantly in men. These cysts can present as a diagnostic conundrum given their rarity and difficulty of distinguishing these cysts from those with malignant potential. We present an incidental case of a LEC in a middle-aged man.

Analysis of Biopsies From Duodenal Bulbs of All Endoscopy Patients Increases Detection of Abnormalities but has a Minimal Effect on Diagnosis of Celiac Disease.

BACKGROUND & AIMS: In patients with positive results from serologic tests for celiac disease, analysis of tissues samples from the duodenal bulb, in addition to those from other parts of the small bowel, might increase the diagnostic yield. However, biopsies are not routinely collected from the duodenal bulb because of concerns that villous atrophy detected there could be caused by other disorders (Brunner glands or peptic duodenitis, gastric metaplasia, shorter villi, or lymphoid follicles). We investigated whether analysis of biopsies from duodenal bulbs of all patients undergoing endoscopy (a population with a low probability for celiac disease) increases diagnoses of celiac disease. METHODS: We performed a retrospective analysis of data from 679 patients (63% female; mean age, 50 years) from whom duodenal bulb and small bowel biopsies were collected during endoscopy at 3 Mayo Clinic sites, from January 1, 2011 through December 31, 2011. Records were reviewed for age, sex, pathology findings, serology test results (HLA DQ2 or DQ), indications for biopsy analyses, and adherence to a gluten-free diet. Patients with celiac disease were identified on the basis of increased intraepithelial lymphocytosis, with or without villous atrophy and crypt hyperplasia, and results from serology tests. Findings from duodenal bulbs were compared with diagnoses using the Fisher exact test. RESULTS: Of all patients undergoing endoscopy, 16 patients (2%) were found to have celiac disease. Analysis of the duodenal bulb biopsies identified 1 patient (0.1%) with celiac disease limited to this region. Of 399 patients whose celiac serology was not known before endoscopic examination, only 2 patients had histologic changes consistent with celiac disease but not limited to duodenal bulb. Abnormal duodenal histology was detected in 265 patients (39%), most commonly in the bulb (n = 241; P < .0001). Of abnormal bulb histologies, chronic peptic duodenitis was most common (observed in 114 patients, 47%). In patients with a normal distal duodenum (n = 576), the duodenal bulb had abnormal histology in 162 (28%). CONCLUSIONS: In a low pretest probability cohort, separate sampling of the duodenal bulb had minimal effect on celiac disease detection. Abnormal histologic findings are more commonly detected in the duodenal bulb; although they do not seem to impair identification of celiac disease, their clinical implications are unclear.