Late onset CMV disease presenting as a colonic stricture in a liver transplant recipient.

Cytomegalovirus (CMV) is a common opportunistic infection in solid organ transplant (SOT) recipients in the first 6 months after transplant. Late onset CMV infection or disease outside the classical risk period is uncommon and can present with atypical signs and symptoms. Here, we report a case of late onset CMV presenting as a colonic stricture more than 10 years after liver transplantation in the absence of traditional CMV risk factors. We also briefly review CMV colitis presenting as a mass or stricture in SOT recipients.

Flexible Sigmoidoscopy Rather than Colonoscopy Is Adequate for the Diagnosis of Ipilimumab-Associated Colitis.

OBJECTIVES: Treatment with ipilimumab, a cytotoxic T lymphocyte antigen-4 approved for metastatic melanoma can result in clinically significant immune-mediated drug injury in the form of colitis. Timely diagnosis and response are essential for optimal management. The aims of our study were to determine the percentage of our patients with ipilimumab-associated colitis in which the colitis could be diagnosed by flexible sigmoidoscopy only and to describe the variations in endoscopic and histologic findings as well as the patients' clinical courses. METHODS: We retrospectively reviewed 244 patients with metastatic melanoma, treated them with ipilimumab, and characterized the endoscopic and histologic features for those who developed colitis. RESULTS: Of the 68 patients who presented with diarrhea, 33 were diagnosed as having ipilimumab-associated colitis. Endoscopically, all of them had involvement of the left side of the colon; none of the patients were noted to have isolated right colon involvement. CONCLUSIONS: Ipilimumab-associated colitis can be diagnosed with a flexible sigmoidoscopy alone, obviating the need for full colonoscopy.

A Complete Pathological Response to Pembrolizumab following ex vivo Liver Resection in a Patient with Colorectal Liver Metastases.

Advances in the systemic treatment of stage IV colorectal cancer with liver metastases has offered improved survival rates for patients who otherwise face a dismal prognosis. However, a pathologically complete response (PCR) to chemotherapy for colorectal liver metastases is still rare, and its significance is not fully understood. In this case report, we describe a patient who achieved PCR after neoadjuvant immunotherapy with pembrolizumab and a left hepatectomy using an ex vivo resection technique.

Prevalence of oesophageal epidermoid metaplasia in 1048 consecutive patients and 58 patients with squamous neoplasms.

AIMS: Oesophageal epidermoid metaplasia is defined by a dense granular layer with overlying hyperorthokeratosis, resembling the epidermis of skin. A possible association between epidermoid metaplasia, squamous dysplasia and squamous cell carcinoma has been proposed. The aim of this study was to compare the prevalence of epidermoid metaplasia in patients with oesophageal squamous neoplasms with that in a control cohort. METHODS AND RESULTS: Medical records and slides from 1048 consecutive oesophageal biopsies and resections for any indication and 58 patients with oesophageal squamous neoplasms were reviewed. Two cases (0.19%) of epidermoid metaplasia were identified in the 1048-patient control group. The prevalence of epidermoid metaplasia was significantly higher (P < 0.05) in the 58 patients with oesophageal squamous neoplasms, two of whom (3.5%) had concurrent epidermoid metaplasia (odds ratio 18.1, 95% confidence interval 2.5-131). One case was associated with a verrucous carcinoma and the other with a well-differentiated, superficial (pT1), exophytic squamous cell carcinoma. No patients had epidermoid metaplasia in a biopsy prior to the diagnosis of squamous neoplasia. CONCLUSIONS: The increased prevalence of epidermoid metaplasia observed in patients with squamous neoplasms provides some additional support for the proposed association. The hypothesis that epidermoid metaplasia is a precursor to squamous neoplasms remains unproven.

Mutually exclusive extracellular signal-regulated kinase pathway mutations are present in different stages of multi-focal pulmonary Langerhans cell histiocytosis supporting clonal nature of the disease.

AIMS: Pulmonary Langerhans cell histiocytosis (PLCH) is an idiopathic cigarette smoking-related disorder of the lung. Molecular changes in cellular or fibrotic stages of PLCH have not been investigated. We studied the prevalence of extracellular signal-regulated kinase (ERK) pathway mutations in different PLCH stages and other non-PLCH smoking-related lung diseases. METHODS AND RESULTS: The cohort included 28 PLCH with cellular (n = 10), mixed cellular/fibrotic (n = 4) and fibrotic histology (n = 14). Seven cases had concurrent multi-focal/multi-lobar tumours. Respiratory bronchiolitis interstitial lung disease (RB-ILD, n = 2), desquamative interstitial pneumonia (DIP, n = 4) and mixed RB-ILD/DIP (n = 2) were included for comparison. BRAF(V) (600E) immunohistochemistry, next-generation sequencing (NGS) and peptide nucleic acid (PNA) clamp polymerase chain reaction (PCR) with high analytical sensitivity (<0.1-0.2%) were used to analyse RAS, BRAF and MAP2K1 genes. Of 26 cases with gene mutation data, BRAF(V) (600E) was identified in eight of 12 (67%) cellular cases and in one of 14 (7%) fibrotic cases. MAP2K1 or KRAS mutations were observed in four of 14 (29%) fibrotic cases and three of the 12 (25%) cellular cases. Multi-focal/multi-lobar specimens carried identical BRAF (n = 5) or non-hotspot MAP2K1 (n = 2) mutations. The other smoking-related disorders were negative for mutations. Patients with cellular lesions or BRAF mutation were significantly younger than patients with fibrotic or BRAF wild-type PLCH. CONCLUSION: The presence of identical but mutually exclusive ERK pathway mutations in multi-focal PLCH supports a neoplastic/clonal origin for this disease. Patient age and mutation type differed between cellular and fibrotic histology and may indicate a natural progression or a mutation-specific pathogenicity.

Evaluation of radiofrequency ablation using the 1-Fr wire electrode in the porcine pancreas, liver, gallbladder, spleen, kidney, stomach, and lymph nodes: A pilot study.

OBJECTIVES: The frequency of detecting asymptomatic incidental lesions of the pancreas is increasing. A substantial number of these lesions are either malignant or premalignant, thus mandating pancreatic resection. A less invasive treatment option may be feasible for selected patients. Endoscopic ultrasound-guided radiofrequency ablation (RFA) may be offered as a treatment option for these patients. The objective of this study was to evaluate the performance characteristics of monopolar RFA using a 1-Fr wire electrode in the porcine pancreas, liver, gallbladder, spleen, kidney, stomach, and lymph nodes. METHODS: Six Yorkshire pigs were used for this study. The internal organs were accessed after a midline laparotomy. Manual monopolar RFAs were performed over a 90-second period using a wide range of power settings (3, 4, 5, 10, 15, and 25 W). The pancreas was exposed at all power settings; the other organs were exposed at power settings of 3, 4, 5, and 10 W. The maximum diameter of coagulative necrosis was measured. RESULTS: In all study animals, RFA was performed in the target organs without difficulty. Only the pancreas showed definite coagulative necrosis. The maximum diameter of coagulative necrosis (8.0±1.7 mm) was achieved at 5 W. No definite coagulative necrosis was noted in the other organs. CONCLUSIONS: Monopolar RFA using a 1-Fr wire electrode resulted in coagulative necrosis in the porcine pancreas. RFA in higher power settings resulted in relatively homogeneous necrosis. At a given power setting, the RFA effect is likely to be differ according to electrical properties of the target tissue. This article is protected by copyright. All rights reserved.

Progressive Familial Intrahepatic Cholestasis-2 Mimicking Non-accidental Injury.

Progressive familial intrahepatic cholestasis (PFIC) is a heterogeneous group of disorders characterized by defective secretion of bile acids or transport defects resulting in progressive cholestasis. These disorders usually present during infancy or childhood and are associated with progressive liver disease. PFIC is estimated to affect 1 in 50,000-100,000 births, with PFIC-2 representing half of PFIC cases. PFIC-2 presents with hepatosplenomegaly, jaundice, pruritus, fat-soluble vitamin deficiencies, and growth failure. Laboratory findings include low/normal gamma glutamyl transpeptidase levels and elevated bilirubin, transaminases, and alpha-fetoprotein levels. In this report, we present a case of PFIC-2 presenting with severe coagulopathy, bruising, subcutaneous hematomas, and acute-onset anemia.

Histologic Features of Syphilitic Gastritis: A Rare but Resurging Imitator of Common Diseases.

OBJECTIVES: The range of histopathologic features of gastric syphilis is not well described. Here we describe the clinicopathologic findings of eight patients with syphilitic gastritis. METHODS: A search of our Pathology Data System (2003-2022) and multiple other institutions identified eight patients with syphilitic gastritis. Clinical information, pathology reports, and available slides were reviewed. RESULTS: Lesions predominated in middle-aged adults (mean age, 47.2 years; range, 23-61 years) with a propensity for men (n = 7). Three patients had a documented history of human immunodeficiency virus. Clinical presentations included weight loss, abdominal pain, hematochezia, fever, dyspepsia, nausea and vomiting, hematemesis, anemia, and early satiety. Endoscopic findings included ulcerations, erosions, abnormal mucosa, and nodularity. All specimens shared an active chronic gastritis pattern with intense lymphohistiocytic infiltrates, variable plasma cells, and gland loss. Prominent lymphoid aggregates were seen in four specimens. The diagnosis was confirmed either by immunostain for Treponema pallidum (n = 7) or by direct immunofluorescence staining and real-time polymerase chain reaction (n = 1). All patients with available follow-up data showed resolution of symptoms after antibiotic therapy (n = 4). CONCLUSIONS: Recognition of the histologic pattern of syphilitic gastritis facilitates timely treatment, prevents further transmission, and avoids unnecessarily aggressive treatment.

Colitis promotes neuronal differentiation of Sox2+ and PLP1+ enteric cells.

Mechanisms mediating adult enteric neurogenesis are largely unknown. Using inflammation-associated neurogenesis models and a transgenic approach, we aimed to understand the cell-source for new neurons in infectious and inflammatory colitis. Dextran sodium sulfate (DSS) and Citrobacter rodentium colitis (CC) was induced in adult mice and colonic neurons were quantified. Sox2GFP and PLP1GFP mice confirmed the cell-type specificity of these markers. Sox2CreER:YFP and PLP1creER:tdT mice were used to determine the fate of these cells after colitis. Sox2 expression was investigated in colonic neurons of human patients with Clostridium difficile or ulcerative colitis. Both DSS and CC led to increased colonic neurons. Following colitis in adult Sox2CreER:YFP mice, YFP initially expressed predominantly by glia becomes expressed by neurons following colitis, without observable DNA replication. Similarly in PLP1CreER:tdT mice, PLP1 cells that co-express S100b but not RET also give rise to neurons following colitis. In human colitis, Sox2-expressing neurons increase from 1-2% to an average 14% in colitis. The new neurons predominantly express calretinin, thus appear to be excitatory. These results suggest that colitis promotes rapid enteric neurogenesis in adult mice and humans through differentiation of Sox2- and PLP1-expressing cells, which represent enteric glia and/or neural progenitors. Further defining neurogenesis will improve understanding and treatment of injury-associated intestinal motility/sensory disorders.

Significance of proximal margin involvement in low-grade appendiceal mucinous neoplasms.

CONTEXT: Appendiceal adenomas and low-grade appendiceal mucinous neoplasms (LAMNs) confined to the appendix are cured by appendectomy. However, involvement of the proximal margin raises concern for residual disease. Some patients with a positive margin at appendectomy undergo cecal resection to eliminate a perceived risk for tumor recurrence or dissemination, although that likelihood is assumed rather than demonstrated. OBJECTIVE: To determine whether involvement of the proximal appendiceal resection margin by adenoma or LAMN is a risk factor for local development of recurrence or pseudomyxoma peritonei. DESIGN: Appendiceal adenomas and LAMNs confined to the appendix were considered for the study if they showed neoplasia or dissecting mucin at the proximal margin. The presence or absence of residual tumor in cecal resections was determined. Follow-up data were obtained from clinical records. RESULTS: Sixteen patients (14 female, 2 male) with LAMN (n = 15) or adenoma (n = 1) and an involved proximal resection margin were identified, including 9 with neoplastic epithelium within the lumen and 7 with acellular mucin in the appendiceal wall at the margin. Six patients underwent cecal resection and the others were nonsurgically followed. No cecal resection had residual neoplasia. No patient developed recurrence or pseudomyxoma peritonei (mean follow-up, 4.7 years). CONCLUSIONS: In patients with LAMNs confined to the appendix, involvement of the appendectomy margin by neoplastic epithelium or acellular mucin does not predict recurrence of disease, even without further surgery. A conservative approach to managing these patients can be justified.

Colitis induces enteric neurogenesis through a 5-HT4-dependent mechanism.

BACKGROUND: The intestine is known to contain enteric neuronal progenitors, but their precise identity and the mechanisms that activate them remain unknown. Based on the evidence for the neurogenic role of serotonin (5-HT) in the postnatal gut and the observation of enteric neuronal hyperplasia in inflammatory bowel disease, we hypothesized that colitis induces a neurogenic response through 5-HT4 receptor signaling. METHODS: We examined the effects of 5-HT4 agonism on colonic neurogenesis and gliogenesis in vitro and in vivo in adult mice using dextran sodium sulfate to experimentally induce colitis. RESULTS: In vitro, 5-HT4 agonism led to increased neuronal proliferation and density. Induction of experimental colitis in vivo similarly resulted in increased numbers of myenteric neurons, and this was inhibited by 5-HT4 antagonism. Interestingly, both in vitro and in vivo, 5-HT4 signaling increased glial cell proliferation but did not increase glial cell numbers, leading us to hypothesize that glia may give rise to neurons. After induction of colitis in normal, Nestin-GFP and Sox2-GFP transgenic mice, it was revealed that multiple glial markers (Sox2, Nestin, and CD49b) became strongly expressed by enteric neurons. Immunoselected enteric glia were found to give rise to neurons in culture, and this was inhibited in the presence of 5-HT4 blockade. Finally, isolated glia gave rise to a neuronal network upon transplantation into aganglionic embryonic avian hindgut. CONCLUSIONS: These results show that colitis promotes enteric neurogenesis in the adult colon through a serotonin-dependent mechanism that drives glial cells to transdifferentiate into neurons.

Interinstitutional whole slide imaging teleconsultation service development: assessment using internal training and clinical consultation cases.

CONTEXT: Assessment of accuracy and feasibility of whole slide imaging (WSI) for interinstitutional consultation in surgical pathology. OBJECTIVES: To train technical and pathologist staff in WSI technology, establish and evaluate a WSI workflow using training cases and second-opinion consultations, and assess diagnostic accuracy. DESIGN: First, WSI training and evaluation using selected subspecialty service cases were performed and compared with the clinical glass slide (GS) diagnosis. Second, WSI and GS diagnoses of consecutive, second-opinion consultation cases were compared. Discrepancies underwent adjudication to determine a reference diagnosis. Participant observations on WSI initiation to practice were gathered. RESULTS: There were 130 cases evaluated, with 123 correlations (94.6%) and 6 minor (4.6%) and 1 major (0.8%) discrepancies. The 74 consultation cases interpreted had 52 correlations (70.3%), and 18 minor (24.3%) and 4 major (5.4%) discrepancies. The WSI and GS adjusted major discrepancy rates in second-opinion consultations were 2.7% (2 of 74) and 4.1% (3 of 74), respectively. Statistical analysis showed that WSI was not inferior to GS interpretation. Pathologists agreed the software was easy to use and the images were adequate, but more time was spent rendering WSI interpretations. CONCLUSIONS: A significant learning curve was observed in the transition from the training set to clinical consultation cases associated both with WSI interpretation and adjustments to the digital analogs of routine GS workflow. Results from second-opinion consultations indicated that WSI interpretation was as accurate as GS interpretation among properly trained and experienced users. Overall, WSI-based practice appears feasible for second-opinion consultations.

BRAF V600E immunohistochemistry is reliable in primary and metastatic colorectal carcinoma regardless of treatment status and shows high intratumoral homogeneity.

In colorectal carcinoma the evaluation of BRAF mutation status is increasingly being performed given its utility as a prognostic and predictive biomarker. However, there are conflicting reports of the sensitivity and specificity of BRAF V600E immunohistochemistry (IHC), and little is known about its reliability in tissues collected from metastatic sites or after chemotherapy, radiation therapy and/or targeted therapy. The degree of intratumoral staining heterogeneity is also not well established. We performed IHC for BRAF V600E (VE1) on 204 cases of colorectal carcinoma including 59 with the BRAF V600E mutation. These included primary (n=147) and metastatic/recurrent (n=57) tumors, collected before (n=133) or after (n=71) chemotherapy, radiation therapy and/or targeted therapy. Evaluation of a test cohort (39 cases) with knowledge of mutation status established a specific staining pattern for the mutation: diffuse cytoplasmic staining of near-uniform intensity, regardless of strength of staining. Using this pattern, pathologists at 3 levels of training independently performed blinded evaluation of the remaining cases. BRAF V600E staining was 96.3% sensitive and 98.5% specific for the mutation, including both pretreatment and posttreatment specimens. Fleiss κ for interobserver agreement was 0.96. Staining of whole sections of the BRAF mutants showed diffuse staining in all cases and uniform or near-uniform intensity in 91%. In 20 cases with both pretreatment and posttreatment specimens, there was 100% accuracy and agreement in staining between samples. We conclude that BRAF V600E IHC is reliable for the evaluation of mutational status in colorectal carcinoma regardless of site or prior treatment history, and staining shows a high degree of intratumoral homogeneity.

Syphilis presenting as inflammatory tumors of the liver in HIV-positive homosexual men.

Syphilis, a sexually transmitted infection caused by the spirochete Treponema pallidum, has seen a resurgence since 2001, particularly in men who have sex with men. Syphilis can affect the liver during the secondary stage as syphilitic hepatitis and during the tertiary stage as gummas. We describe 3 cases of syphilis in human immunodeficiency virus-positive homosexual men that presented as hepatic mass lesions clinically suspected of being malignant tumors. Histologically, 2 of the 3 cases showed a plump spindle cell proliferation, mixed inflammatory infiltrate with numerous neutrophils, and abscesses, whereas the third case showed granulomas and pericholangitis/cholangitis. Immunohistochemical staining for T. pallidum showed innumerable organisms in 2 of the cases. Pathologists must be aware of the possibility of syphilis causing hepatic inflammatory masses in human immunodeficiency virus-positive men who have sex with men in order to avoid misdiagnosis or delayed treatment.

Delineating breast ductal carcinoma using combined dye-enhanced wide-field polarization imaging and optical coherence tomography.

Intra-operative delineation of breast cancer is a challenging problem. We used dye-enhanced wide-field polarization imaging for rapid demarcation of en face cancer margins and optical coherence tomography (OCT) for cross-sectional evaluation. Ductal carcinoma specimens were stained with methylene blue. Wide-field reflectance images were acquired at 440 and 640 nm. Wide-field fluorescence images were excited at 640 nm and registered between 660 nm and 750 nm. OCT images were acquired using a 1310 nm swept-source system. The results were validated against histopathology. Both imaging modalities provided diagnostic information on cancer margins. Combined OCT and wide-field polarization imaging shows promise for intra-operative detection of ductal breast carcinoma.

Multimodal optical imaging for detecting breast cancer.

The goal of the study was to evaluate wide-field and high-resolution multimodal optical imaging, including polarization, reflectance, and fluorescence for the intraoperative detection of breast cancer. Lumpectomy specimens were stained with 0.05 mg/ml aqueous solution of methylene blue (MB) and imaged. Wide-field reflectance images were acquired between 390 and 750 nm. Wide-field fluorescence images were excited at 640 nm and registered between 660 and 750 nm. High resolution confocal reflectance and fluorescence images were excited at 642 nm. Confocal fluorescence images were acquired between 670 nm and 710 nm. After imaging, the specimens were processed for hematoxylin and eosin (H&E) histopathology. Histological slides were compared with wide-field and high-resolution optical images to evaluate correlation of tumor boundaries and cellular morphology, respectively. Fluorescence polarization imaging identified the location, size, and shape of the tumor in all the cases investigated. Averaged fluorescence polarization values of tumor were higher as compared to normal tissue. Statistical analysis confirmed the significance of these differences. Fluorescence confocal imaging enabled cellular-level resolution. Evaluation and statistical analysis of MB fluorescence polarization values registered from single tumor and normal cells demonstrated higher fluorescence polarization from cancer. Wide-field high-resolution fluorescence and fluorescence polarization imaging shows promise for intraoperative delineation of breast cancers.

The relationship of myocardial bridges to coronary artery dominance in the adult human heart.

Myocardial bridging is recognized as an anatomical variation of the human coronary circulation in which an epicardial artery lies in the myocardium for part of its course. Thus, the vessel is 'bridged' by myocardium. The anterior interventricular branch of the left coronary artery has been reported as the most common site of myocardial bridges but other locations have been reported. The purpose of this study was to provide more definitive information on the vessels with myocardial bridges, the length and depth of the bridged segment, and the relationship between the presence of bridges and coronary dominance. Two hundred formalin-fixed human hearts were examined. Myocardial bridges were found in 69 (34.5%) of the hearts with a total of 81 bridges. One bridge was found in 59 of these hearts and multiple bridges were observed in ten (eight with double bridges and two with triple bridges). Bridges were most often found over the anterior interventricular artery (35 hearts). Bridges were also found over the diagonal branch of the left coronary artery (14), over the left marginal branch (five) and over the inferior interventricular branch of the left coronary artery (six). Bridges were also found over the right coronary artery (15 hearts), over the right marginal branch (four) and over the inferior interventricular branch of the right coronary artery (two). The presence of bridges appeared to be related to coronary dominance, especially in the left coronary circulation. Forty-six (66.6%) of the hearts with bridges were left dominant. Forty-two of these had bridges over the left coronary circulation and four over the right coronary circulation. Seventeen hearts (24.6%) were right dominant. Eleven of these had bridges over the right coronary circulation and six over the left coronary circulation. The remaining six hearts were co-dominant with four having bridges over the left coronary circulation and two over the right coronary circulation. The mean length of the bridges was 31 mm and the mean depth was 12 mm. The possible clinical implications of myocardial bridging may vary from protection against atherosclerosis to systolic vessel compression and resultant myocardial ischaemia.