Deep Biopsy Research Articles

Basosquamous Carcinoma: A Commentary.

Simple SummaryBasosquamous carcinoma is a rare, aggressive non-melanoma skin cancer with features that lie between those of basal cell carcinoma and squamous cell carcinoma. A lot of controversy has been raised around the classification, pathogenesis, histologic morphology, biologic behavior, prognosis and management of this tumor. This is a narrative review based on articles published on PubMed in English language which had in their title the terms “basosquamous carcinoma” and/or “metatypical carcinoma of the skin”. The aim of this review was to summarize and evaluate the latest data of the English literature regarding epidemiology, clinical presentation, dermoscopic and histopathologic characteristics, as well as the genetics and management of BSC to better characterize basosquamous skin lesions.Basosquamous carcinoma is a rare, aggressive non-melanoma skin cancer with features that lie between those of basal cell carcinoma and squamous cell carcinoma. A lot of controversy has been raised around the classification, pathogenesis, histologic morphology, biologic behavior, prognosis and management of this tumor. This is a narrative review based on an electronic search of articles published in PubMed in English language which had in their title the terms “basosquamous carcinoma” and/or “metatypical carcinoma of the skin”. The aim of this review was to summarize and evaluate current data regarding epidemiology, clinical presentation, dermoscopic and histopathologic characteristics, as well as the genetics and management of BSC, in order to shed some more light onto this intriguing entity. As a conclusion, dermoscopy, deep incisional biopsies and immunohistologic techniques (Ber-EP4) should be applied in clinically suspicious lesions in order to achieve an early diagnosis and better prognosis of this tumor. Surgical treatments, including wide excision and Mohs’ micrographic surgery, remain the treatment of choice. Finally, vismodegib, a Hedgehog pathway inhibitor, must be thoroughly investigated, with large controlled trials, since it may offer an alternative solution to irresectable or difficult-to-treat, locally advanced cases of basosquamous carcinoma.

QOLP-25. PERFORMANCE STATUS OF PEDIATRIC PATIENTS WITH CENTRAL NERVOUS SYSTEM TUMORS TREATED IN A TERTIARY CENTER IN MEXICO, A SINGLE-CENTER EXPERIENCE

Abstract BACKGROUND Central nervous system (CNS) tumors are the most common solid neoplasms in the pediatric age. Despite this, there are no reports of results focused on the performance status of pediatric patients who are treated in a multidisciplinary setting. OBJECTIVE Describe the Performance Status of CNS pediatric patients after being treated with a multidisciplinary approach in a tertiary center. METHODS We review the chart of the pediatric patients at the Teleton Children Oncology Hospital from December 2014 to December 2019. The performance status was evaluated either using ECOG, Karnofsky, or Lansky scores. The multidisciplinary approach at our hospital includes: A Well-Equipped Diagnostic Center, integrated by a CAP-accredited laboratory, a Molecular Biology Unit, and the Imaging Unit, including a high-quality 2 tesla MRI. The surgical equipment comprises a surgical microscope, bipolar coagulation equipment, microsurgical instruments, and craniotomy equipment. For deep biopsies or functional surgery, we use Frame-Based Stereotactic Systems (FBSS) and neuronavigation systems. We provide first-line chemotherapy protocols and have a radiotherapy unit that can start treatment within a week. We have an Intensive Care Unit for oncologic patients with a 93% of overall survival. We provide ludic therapy and cognitive behavioral therapy, as well as emotional support. The Physical Rehabilitation Clinic uses the Bobath concept, proprioceptive and neuromuscular techniques as well as follow-up visits according to needs. RESULTS Of the 56 patients treated, 35 were evaluated with ECOG/Lansky performance status scale during the last follow up visit, resulting in 74.2% with a fully active performance, able to carry on all pre-disease activities without restriction. CONCLUSION A multidisciplinary approach is essential in the management of pediatric patients with CNS tumors. Efforts should be aimed at reducing post-surgical morbidity and early rehabilitation to reintegrate patients into society in the long term as we described many of them have an excellent performance status.

Intravascular large B-cell lymphoma in random deep skin biopsies as a cause of pyrexia of unknown origin.

Intravascular large B-cell lymphoma in random deep skin biopsies as a cause of pyrexia of unknown origin.

Hist-P-05 - A rare primary subcutaneous panniculitis-like T-cell lymphoma with scalp involvement associated with lupus panniculitis

Hist-P-05 - A rare primary subcutaneous panniculitis-like T-cell lymphoma with scalp involvement associated with lupus panniculitis

The Pathologic Confirmation in Subepithelial Tumors

Background/Aims: Subepithelial tumors (SETs) are small, mostly asymptomatic lesions with normal overlying mucosa, usually identified incidentally on endoscopy. The aim of this study was to evaluate the pathologic diagnosis of SETs, and to assess the diagnostic yield and impact of endoscopic submucosal dissection (ESD) biopsy on the management of patients with SETs.Materials and Methods: We included 52 subepithelial lesions in this study during the study period. Inclusion criteria included size of the SET >2 cm, and a gastrointestinal stromal tumor (GIST) that cannot be excluded using EUS. We performed an endoscopic biopsy of each SET using the ESD technique.Results: The mean diameter of the lesions was 24.15±6.0 mm. The diagnostic yield of this method was 96.15%. Among the 52 participants, 45 were located in the stomach, four in the esophagus, and three in the duodenum. The pathologic diagnoses included: 17 leiomyomas, 13 GISTs, 11 ectopic pancreases, two carcinomas, two inflammatory fibroid polyps, two Brunner’s gland hyperplasia, two lipomas, one glomus tumor, and two remained undiagnosed. The mean duration of the procedure was 13.44±2.41 minutes. Three complications were associated with the procedure.Conclusions: Deep biopsy via ESD is useful in determining the histopathologic nature of SETs. This method minimizes the need for unnecessary surgery in benign SETs.

1700\u2009nm optical coherence microscopy enables minimally invasive, label-free, in vivo optical biopsy deep in the mouse brain

In vivo, minimally invasive microscopy in deep cortical and sub-cortical regions of the mouse brain has been challenging. To address this challenge, we present an in vivo high numerical aperture optical coherence microscopy (OCM) approach that fully utilizes the water absorption window around 1700 nm, where ballistic attenuation in the brain is minimized. Key issues, including detector noise, excess light source noise, chromatic dispersion, and the resolution-speckle tradeoff, are analyzed and optimized. Imaging through a thinned-skull preparation that preserves intracranial space, we present volumetric imaging of cytoarchitecture and myeloarchitecture across the entire depth of the mouse neocortex, and some sub-cortical regions. In an Alzheimer’s disease model, we report that findings in superficial and deep cortical layers diverge, highlighting the importance of deep optical biopsy. Compared to other microscopic techniques, our 1700 nm OCM approach achieves a unique combination of intrinsic contrast, minimal invasiveness, and high resolution for deep brain imaging.

Detection of nerve fibers in the eutopic endometrium of women with endometriosis, uterine fibroids and adenomyosis.

ObjectiveThe primary objective of this study was to establish the presence of nerve fibers in the eutopic endometrium of women with endometriosis and to determine whether these nerve fibers are exclusive to endometriosis or are also found in other pelvic pathologies associated with dysmenorrhea.MethodsEndometrial tissue was obtained by aspiration (Pipelle), endometrial curettage, or following hysterectomy in women with endometriosis confirmed through histopathological examination, leiomyomas, and adenomyosis. The eutopic endometrium was subjected to immunohistochemical staining to detect PGP 9.5, which is a highly specific pan-neuronal marker. The nerve fiber density was correlated with the patient’s pain score, as indicated by the Visual Analog Scale. A control group was formed by staining the endometrium of women presenting with dysmenorrhea but without the above-mentioned disorders.ResultsNerve fibers were observed in sections of the endo-myometrium (in the deep endometrium) in 68% of patients with endometriosis who underwent hysterectomy or a deep endometrial biopsy. Nerve fibers were not observed in the aspirated endometrium of women with endometriosis. Only 13.7% of women with adenomyosis and 3.3% of women with fibroids had nerve fibers in their endometrium. Nerve fiber density was correlated with pain score in women with endometriosis.ConclusionNerve fibers were found in the functional layer of eutopic endometrium in women with endometriosis; hence, we concluded that the presence of nerve fibers in the eutopic endometrium could diagnose endometriosis with a fairly good specificity of 92.7%. However, the absence of nerve fibers does not always exclude the disease.

CRANIOFACIAL OSTEOSARCOMA: A CASE REPORT

<h3>Background</h3> Osteosarcoma is the most common primary bone tumor, with 10% of cases affecting the head and neck. Demographics of head and neck osteosarcoma are different from those elsewhere in the musculoskeletal system. Prognosis is strongly dependent on negative resection margins with the use of neoadjuvant chemoradiotherapy in select cases. <h3>Description</h3> We present a case of a 58-year-old male nonsmoker patient who presented with a lump in his left upper jaw. Clinical examination revealed an exophytic mass in the upper left tuberosity of the maxilla suspicious for squamous cell carcinoma with no associated lymphadenopathy. <h3>Findings</h3> Radiological investigations revealed a metabolically active left maxillary lesion with destruction of the maxillary sinus. Histologic examination of a superficial biopsy initially suggested a proliferative fibro-osseous lesion; however, a second deeper biopsy was diagnostic of osteosarcoma, and the patient was referred to a sarcoma center. Immunohistochemistry showed AE1/AE3 and CK(MNF.116) positivity in occasional cells with a Ki67 proliferation index of 60%. This was diagnostic of grade 2-3 osteosarcoma. Multidisciplinary management of the patient included neoadjuvant chemotherapy and total maxillectomy and dental prosthetic rehabilitation. The patient is still under follow-up. <h3>Conclusions</h3> This case of primary osteosarcoma of the maxilla is rare and scarcely reported in the literature. Clinical differential diagnoses include squamous cell carcinoma, and histologic differential diagnosis includes fibro-osseous proliferative lesions in undersampled cases. It is important to consider osteosarcoma in destructive lesions, as it requires prompt and early specialist intervention to maximize the chances of negative surgical margins, which is the mainstay of treatment for this disease for prognosis.

Deep biopsy via endoscopic submucosal dissection for primary gastric amyloidosis.

Amyloidosis is characterized by interference with multiple organs. It is usually systemic and uncommonly limited to the stomach [1] [2]. Here we report a rare case of primary gastric amyloidosis.

Profiling 523 cancer associated genes in circulating tumor DNA of children with CNS tumors.

3023 Background: Pediatric central nervous system (CNS) cancers often pose unique challenges including tumor ‘invisibility’, where surgical resection is restricted due to the sensitive tumor location and tissue biopsy is not always feasible. Detecting cancer associated mutations and copy number variations (CNV) at diagnosis is increasingly important, as the WHO classification of pediatric CNS cancers has incorporated molecular signatures with tumor grade. To achieve CNS tumor molecular ‘visibility’, we previously established a liquid biopsy platform for detecting single nucleotide variants in circulating tumor DNA (ctDNA). However, our method was limited by the restricted number of genes that can be monitored and the inability to detect genomic events including CNVs. To address this, we developed a deep sequencing liquid biopsy approach to profile alterations across selected genes. Our platform provides an opportunity for multi-gene monitoring, to assess tumor subclonal evolution and response to treatment in the absence of repeat tissue biopsies. Methods: We tested the performance of our platform using paired tissue, CSF, and plasma/serum from 10 children with diffuse midline glioma (DMG). ctDNA was analyzed using the TruSight Oncology 500 (TSO500) ctDNA targeted panel covering 523 genes. Matched tumor, CSF, and blood were assessed for concordance and sequencing results were compared to digital droplet PCR (ddPCR) detection of H3K27M mutation. Results: The median exons with ³500X coverage was 96% for 7 CSF samples with optimal input (³60ng), 0.01% for 3 CSF samples with &lt; 5ng input, and 74.5% for plasma/serum samples. ctDNA was more readily detectable in CSF, yet concordance between paired tumor, CSF and plasma/serum was observed. DMG associated mutations in genes including H3F3A, HIST1H3B, TP53, and ACVR1 were detected in ctDNA. Of 9 H3K27M mutations identified in tumor, 8 were present in CSF and 3 in plasma/serum, for a positive percent agreement of 89% and 33%, respectively, with the tumor results. Among CSF samples, H3.3K27M was detected in 6/6 cases, and H3.1K27M in 2/3 cases, with variant allele frequencies comparable to ddPCR results. CNVs including PDGFRA/B and MDM4 amplifications were present in CSF and confirmed by analysis of paired tumor. Additional events, including PIK3CA p.E545Q, PPM1D truncation, and KRAS amplification, were detected in CSF but absent from paired tumor, indicating tissue heterogeneity. Strategies to optimize ctDNA detection, including optimization of ctDNA isolation and adjustment of library QC metrics, were identified. Conclusions: This proof-of-concept study demonstrates the feasibility of our high depth, targeted sequencing approach for detecting clinically relevant mutations in ctDNA from children with CNS tumors. This approach may aid in diagnosis of CNS tumor molecular subtype, and monitoring of tumor evolution and response to therapy in serially collected ctDNA.

Shave biopsy of pediatric melanocytic tumors compromises staging and therapy planning.

e21576 Background: Melanoma is the dominant skin cancer of pediatric patients, and accounts for 1-3% of pediatric malignancies. The prognosis for both adults and children with melanoma correlates with stage at diagnosis, and initial Breslow depth is a critical determinant. Kaplan-Meier melanoma-specific survival curves show survival rates ranging from 98% (T1a) to 75% (T4b) at 10 years for adult patients with stage I and II disease at diagnosis. Pediatric patients are known to present with thicker primary melanomas as compared to their adult counterparts. The preferred biopsy method of the American Academy is Dermatology for melanoma is excisional, however partial shave biopsy is most frequently performed in children, given its simplicity, efficiency, and often low clinical suspicion for cutaneous malignancy. Despite the ease of this biopsy technique, shave biopsy has a high rate of base transection, reducing accuracy of microstaging, which is crucial for therapy planning. Methods: Retrospective chart review evaluation of the potential effects of biopsy method on staging, surgical recommendations, and treatment approach for pediatric patients with melanocytic tumors. Results: Data was available for 91 pediatric patients with a spectrum of melanocytic tumors ranging from atypical with unknown malignant potential, to melanoma. Patient characteristics including gender, age at biopsy, biopsy method, status of biopsy margins, recommendations for re-excision, sentinel lymph node biopsy, and treatment plan were collected and analyzed. There were 48 females and 43 males with age range 1—22 years (mean 10 years). Sixty-eight of 91 (75%) tumors had a positive margin (deep, peripheral, or both) on diagnostic biopsy, 52/68 (76.5%) were obtained using shave method. Evaluating the deep margin specifically, 50/91 (55%) tumors had a positive deep margin, 46/50 (92%) of which were obtained using shave method. No tumor evaluated by punch had a positive deep margin (0/18). Of all shave biopsies, 77% had positive deep margin as opposed to only 13% using alternative biopsy methods. In 10/91 (11%) patients, surgical recommendations were changed based on inaccurate microstaging and positive deep biopsy margins, 9/10 (90%) of these patients had undergone shave biopsy. Most (8/10) patients had melanoma, the remaining 2/10 had highly atypical spitzoid tumors in which melanoma could not be ruled out. Conclusions: Pediatric patients with melanocytic tumors most commonly underwent shave biopsy as the initial diagnostic biopsy method. This method of biopsy was associated with higher incidence of positive margins at diagnosis and more aggressive definitive surgical management. These findings suggest that more routine use of excisional biopsy in pediatric patients with lesions being evaluated for malignancy could decrease the incidence of inaccurate microstaging and reduce the need for more aggressive definitive surgical management.

Een link tussen oedemen en eosinofilie: eosinofiele fasciitis

A link between oedema and eosinophils: eosinophilic fasciitis A 65-year-old man presented with progressive swelling in his 4 limbs. The skin on his limbs was oedematous and indurated, with an orange peel skin and blistering in some places, as well as a groove sign over the tibia. Lab results showed a remarkable eosinophilia of 23% (reference ≤ 6%). A deep skin biopsy revealed fascial infiltration and fibrin deposition, consistent with eosinophilic fasciitis (EF). EF is a rare cause of fasciitis, eosinophilia and polyclonal hypergammaglobulinemia. Because of its rarity, diagnostic delay is usually significant. Corticosteroids are the mainstay of therapy, but because of an incomplete response and the need for long-term treatment, corticosteroid sparing agents are often associated.

Is There Pathological Uniformity between the Periphery and Center of a Gastrointestinal Stromal Tumor?

Background: Gastrointestinal stromal tumors (GISTs) are mesenchymal tumors and have some malignant potential. Mitotic count is important for predicting the malignant potential of GISTs. Proper treatment of GISTs requires accurate pathological diagnosis. In general, endoscopic ultrasound-guided fine-needle aspiration and deep biopsy are used for pathological diagnosis of GIST before making decisions about surgery. This study sought to evaluate the pathological uniformity of gastric GISTs for mitotic index of the center and periphery of the GIST. Methods: We retrospectively reviewed the data of 37 gastric GIST patients who underwent wedge resection at Hanyang University Hospital. We used Armed Forces Institute of Pathology criteria to classify gastric GISTs. To determine the pathological uniformity of gastric GISTs, we compared GIST risk stratification between the center and periphery of GISTs. Results: The mean size of GISTs was 3.56 ± 2.10 cm. Three lesions were located in the antrum, 11 in the fundus, 9 in the cardia, and 14 in the body. The mean age of patients was 58.65 ± 9.44 years; 18 patients were male and 19 were female. Thirty-five patients (94.6%) showed the same level of risk stratification between the center and periphery of gastric GISTs, while two patients (5.4%) presented different levels of risk between the two sites. No significant difference in mitotic count was observed between the two sites (kappa value = 0.863; p = 0.001). Conclusions: Mitotic index category (either more than five mitoses per high-power field or five or fewer mitoses per high-power field) of GISTs showed good concurrence between the center and periphery.

Polyarteritis Nodosa: A Systematic Review of Test Accuracy and Benefits and Harms of Common Treatments.

ObjectiveThe object of this study was to analyze the benefits and harms of different treatment options and to analyze test accuracy used in the evaluation of patients with primary systemic polyarteritis nodosa (PAN).MethodsA systematic search of published English‐language literature was performed in Ovid Medline, PubMed, Embase, and the Cochrane Library from the inception of each database through August 2019. Articles were screened for suitability in addressing patient, intervention, comparison, and outcome questions, with studies presenting the highest level of evidence given preference.ResultsOf 137 articles selected for data abstraction, we analyzed 21 observational studies and seven randomized controlled trials (RCTs). The results showed indirect evidence that a deep skin biopsy provides good diagnostic accuracy. A combined nerve and muscle biopsy should be obtained for patients with PAN with peripheral neuropathy. Cyclophosphamide with high‐dose glucocorticoids (GCs) is effective as an induction treatment for newly diagnosed active and severe PAN. GC monotherapy is adequate in the majority of patients with nonsevere PAN, although it has a high relapse rate with GC taper. There was insufficient data in determining the optimal duration of non‐GC and GC maintenance therapy. Tumor necrosis factor inhibitors are effective treatment for patients with deficiency of adenosine deaminase 2 (DADA2) with stroke and vasculitis manifestations.ConclusionThis comprehensive systematic review synthesizes and evaluates the harms and benefits of different treatment options and the accuracy of commonly used tests for the diagnosis of systemic PAN. Data for diagnosis and management of PAN and DADA2 are mostly limited to observational studies. More high‐quality RCTs are needed.

Solitary Fibrous Tumor Low Rectum Simulating Cancer

Introduction: The solitary fibrous tumor is a benign mesenchymal tumor of rare extra-pleural location. We report a case of solitary fibrous tumor observed in the lower rectum simulating cancer. The objective was to discuss the diagnostic and therapeutic management of the solitary fibrous in Madagascar. Observation: This is a sixty-five-year-old man, seen in consultation for dyskinesia, with no family history of neoplasia. The digital rectal examination revealed a large, non-budding, firm mass at the level of the right posterolateral surface with a lower pole located 2 cm from the anal margin, the remains of the physical examination are normal. Abdominal computed tomography showed a mass measuring 8 × 7 × 5.5 cm at the expense of the rectal wall of regular tissue density, without a mesenteric node or secondary localization. the biopsy had not found any malignant cells. This result is due to insufficiently deep biopsy samples of the mass, which led us to perform a complete surgical excision by coloprotectomy. The operative follow-up to which was simple. Immunohistochemical study of the surgical specimen confirmed the diagnosis with a positive CD 34 marker. The outcome was favourable without metastasis or recurrence after a six-month follow-up. Conclusion: The rectal localization of the solitary fibrous tumor is exceptional. The diagnosis is histological confirmed by the immunohistochemical study with a positive CD 34 marker.

Polymorphous adenocarcinoma on the base of tongue: a rare case

Polymorphous adenocarcinoma (PAC) is a distinct neoplasm of the minor salivary gland. Most patients present with an asymptomatic mass in the hard palate.” Rarely, “the mass can also occur in the” base of the tongue. A 56-year-old female patient, presented to ENT clinic, Teaching Hospital Jaffna with a history of voice change for 4 months. Her physical examination revealed fissured tongue, a mass of 1×1.5 cm in size with intact mucosa located at the left side of the base of tongue, which was crossing the midline and infiltrated into the deep tongue muscles. Deep biopsy revealed polymorphous adenocarcinoma. She was treated with radiotherapy. PAC is ‘unusual’ to arise at the base of the tongue. It is important to diagnose and treat it accordingly.

An Unusual Case of Perineural Infiltration and Orbital Invasion of Squamous Cell Carcinoma Associated with Actinic Keratosis

Actinic keratosis is considered a precancerous lesion, constituting a precursor to squamous cell carcinoma (SCC) formation. Perineural invasion has been observed in patients with cutaneous carcinoma due to local subcutaneous tissue destruction and primarily involves the trigeminal nerve due to rich innervation provided by the supraorbital nerve in addition to the facial nerve. An unusual case of perineural infiltration and orbital invasion of squamous cell carcinoma associated with actinic keratosis is presented. A 70-year-old Caucasian woman presented with complete left eye ophthalmoplegia, total left upper-eyelid ptosis, and facial pain with paresthesia. Computed tomography revealed a process of the soft tissues in the left cheek infiltrating the infraorbital canal, pterygopalatine fossa, inferior orbital fissure, and left cavernous sinus with periosteal adherence. Magnetic resonance imaging revealed pathological extension via the left infraorbital canal with a considerable area of necrosis. Treatment of facial actinic keratosis may not prevent malignant transformation and can delay diagnosis and treatment of SCC. A deep biopsy appears to be essential for a correct diagnosis. Perineural spread of cutaneous SCC may be characterized by insidious progression in the cranial trigeminal nerve, abnormal ocular motility, diplopia, or external ophthalmoplegia.

Anaerobic bacterial communities associated with oral carcinoma: Intratumoral, surface-biofilm and salivary microbiota

It was estimated that more than 700 bacterial species inhabit the oral cavity of healthy humans. Anaerobes comprise a significant fraction of the oral bacteriome and play an important role in the formation of multi-species biofilms attached to various anatomical sites. Bacterial biofilms are also associated with pathologic laesions of the oral cavity, including oral squamous cell carcinoma (OSCC), and distinct oral taxa could also be detected within the tumors, i.e. in deep biopsy samples. These observations suggested that certain oral bacteria or oral bacterial communities may play a causative role in oral carcinogenesis, in addition to the well characterized risk factors of oral cancer. Alternatively, it was also proposed that a subset of oral bacteria may have a growth advantage in the unique microenvironment of OSCC. Recently, a series of studies analysed the OSCC-associated bacterial communities using metataxonomic, metagenomic and metatranscriptomic approaches. This review outlines the major differences between the community structure of microbiota in tumor biopsy, surface-biofilm and salivary or oral wash samples collected from OSCC patients, compared to corresponding samples from control persons. A special emphasis is given to the anaerobic bacteria Fusobacterium nucleatum and Fusobacterium periodonticum that were characterised repeatedly as „OSCC-associated” in independent studies. Predicted microbial functions and relevant in vivo experimental models of oral carcinogenesis will also be summarized.

Clinicopathological features of esophageal schwannomas in mainland China: systematic review of the literature.

Esophageal schwannoma (ES) are rare and mostly benign neurogenic tumors. The clinical misdiagnosis rate of it is high. In this study, the clinicopathologic features of ES in mainland China were studied to better understand the disease and improve the diagnosis and treatment rate. A systematic review was conducted in accordance with PRISMA guidelines. The keywords "esophageal schwannoma", "esophageal neurinoma" and "esophageal neurilemoma" were searched for databases such as Pubmed, EMbase, Wanfang Database and Chinese National Knowledge Infrastructure. The search time frame for database was until July 2019. Combined with our patient, the clinicopathological data and the diagnosis and treatment of ES were summarized. ES occurs in the upper part of the mediastinum and in the thoracic esophagus in most patients in the neck, upper and middle segments. CT and PET/CT examinations can be used for diagnosis, but the differentiation value of both benign and malignant ES is similar. The histopathological findings of forceps biopsy specimens are often difficult to diagnose, and deep tissue biopsies may increase pathological accuracy. EUS-FNA is also recommended for ES diagnosis, but it may also be misdiagnosed. Pathological features include a fusiform arrangement in a palisade-like structure or a tumor cell arranged in a network to form a loose structure. ES characteristic immunohistochemistry results showed that S-100 protein has strong immunological activity. The definitive diagnosis requires immunohistochemistry, especially immunological reaction with S-100 protein. The appropriate treatment plan should be selected according to the diameter of the lesion. The overall prognosis of ES is good, but attention should be paid to follow-up.

S2121 Overt Small Bowel Bleeding From a Jejunal GIST

INTRODUCTION: Gastrointestinal stromal tumors (GISTs) are rare causes of gastrointestinal malignancies. Herein we describe a cause of upper GI bleeding from a jejunal GIST. CASE DESCRIPTION/METHODS: A 58-year-old male with history of chronic hepatitis B, hypertension and hyperlipidemia presented to the hospital with melena and lightheadedness. The patient was hemodynamically stable with an elevated BUN/creatinine ratio and initial hemoglobin of 11.5 g/dL. His repeat CBC twelve hours later revealed down trend of hemoglobin to 8.5 g/dL. Review of the patient’s past admission and outpatient history revealed the patient was admitted two years prior for GI bleed requiring multiple blood transfusions. At that time, upper endoscopy, colonoscopy and CT scan of the abdomen/pelvis were unrevealing as was a 99 Technetium bleeding scan. He was discharged and scheduled for outpatient small bowel video capsule but was lost to follow up. He returned to the clinic one year later and repeat upper endoscopy and colonoscopy were performed. Upper endoscopy revealed mild gastritis and colonoscopy revealed medium sized hemorrhoids but he had a poor colon bowel prep. Small bowel video capsule endoscopy revealed AVM's in the proximal small bowel but the study was also poor due to bile obscuring most of the small bowel mucosa. Due to concern for possible small bowel AVM bleed, we opted to perform upper endoscopy with push enteroscopy. A large ulcerated friable nodular mass with stigamata of recent bleeding was identified in the proximal jejunum. Bite on bite biopsies were obtained to evaluate the mass and a tattoo was placed for identification purposes. Despite the deep biopsies, pathology later returned as normal small bowel mucosa. A CT enterography was obtained revealing a 3.5 × 3.6 × 3.5 cm hyperenhancing mass arising from the proximal jejunum with adjacent wall thickening. Surgical consultation was obtained and the patient underwent laparoscopic resection of the mass. Pathology demonstrated low grade spindle-cell type gastrointestinal stromal tumor. DISCUSSION: Although an uncommon cause for GI bleeding overall, GISTs are a common cause of small bowel bleeding. Obtaining a thorough history and evaluation of the patient’s prior outpatient records proved useful in identifying the cause of bleeding in this case even though it was different from what was suspected.Figure 1Figure 2