Acute abdomen in post- Covid 19 multisystem inflammatory syndrome in children. A case report.

AIM: As more data about coronavirus disease-2019 (COVID-19) has been gathered it has become evident that children who have had or have been exposed to COVID-19 can develop a rare complication; multisystem inflammatory syndrome in children (MIS-C). We report the case of a 9-year-old boy, who was brought to the emergency room with suspected acute abdomen and was diagnosed with MIS-C. METHODS: The patient had had a positive molecular test for COVID-19, 25 days earlier and fever that started 4 days prior to presentation, He tested negative for COVID on arrival at the emergency room. After physical examination, and diagnostic tests were performed the differential diagnosis included appendiceal inflammation and MIS-C. Surgical exploration was performed laparoscopically. RESULTS: The immune morphological picture was reactive lymphogranular hyperplasia. Postoperatively the abdominal symptoms improved rapidly but the patient developed diffuse erythema as well as some cardiovascular and neurological disturbances. The patient was discharged on postoperative day 14 in good general condition with a diagnosis of MIS-C. CONCLUSIONS: In patients with a recent positive COVID test and mainly gastroenterological manifestations surgical exploration is necessary in order to prevent delayed diagnosis and inadequate/inappropriate treatment. KEY WORDS: Acute abdomen, COVID-19, MIS-C, Gastrointestinal symptoms.

Laparoscopic appendectomy, stump closure and endoloops: A meta-analysis.

BACKGROUND: Acute appendicitis (AA) is one of the main indications for urgent surgery. Laparoscopic appendectomy (LA) has shown advantages in terms of clinical results and cost-effectiveness, even if there is still controversy about different devices to utilize, especially with regards to the endoloop (EL) vs endostapler (ES) when it comes to stump closure. AIM: To compare safety and cost-effectiveness of EL vs ES. METHODS: From a prospectively maintained database, data of 996 consecutive patients treated by LA with a 3 years-follow up in the department of Emergency General Surgery - St Orsola University Hospital, Bologna (Italy) were retrieved. A meta-analysis was performed in terms of surgical complications, in comparison to the international literature published from 1995 to 2021. RESULTS: The meta-analysis showed no evidence regarding wound infections, abdominal abscesses, and total post-operative complications, in terms of superiority of a surgical technique for the stump closure in LA. CONCLUSION: Even when AA is complicated, the routine use of EL is safe in most patients.

Effect of antithrombotic therapy on postoperative outcome of 538 consecutive emergency laparoscopic cholecystectomies for acute cholecystitis: two Italian center's study.

The risk of developing hemorrhagic complications during or after emergency cholecystectomy (EC) for acute cholecystitis (AC) in patients with antithrombotic therapy (ATT) remains uncertain. In this double-center study, we evaluated post-operative outcomes in patients with ATT undergoing EC. We retrospectively evaluated 538 patients who underwent laparoscopic EC for AC between May 2015 and December 2019 at two referral centers. 89 of them (17%) were on ATT. We defined postoperative complication rates, including bleeding, as our primary outcome. Mortality was higher in the ATT group. Morbidity was higher in the ATT group as well; however, the difference was not statistically significant. 12 patients (2%) experienced intraoperative blood loss over 500 ml and ten (2%) had postoperative bleeding complications. Two patients (< 1%) experienced both intraoperative and postoperative bleeding. On multivariate analysis, ATT was not significantly associated with worse postoperative outcomes. Antithrombotic therapy is not an independently associated factor of severe postoperative complications (including bleeding) or mortality. However, these patients still represent a challenging group and must be carefully managed to avoid postoperative bleeding complications.

Laparoscopic appendectomy as an index procedure for surgical trainees: clinical outcomes and learning curve.

Surgical training is essential to maintain safety standards in healthcare. The aim of this study is to evaluate learning curves and short-term postoperative outcomes of laparoscopic appendectomy (LA) performed by trainees (TRN) and attendings (ATT). The present study included the medical records of patients with acute appendicitis who underwent a fully LA in our department between January 2013 and December 2018. Cases were divided into trainees (TRN and ATT groups based on the experience of the operating surgeon. The primary outcome measures were 30-day morbidity and mortality. Preoperative patients' clinical characteristics, intraoperative findings, operative times, and postoperative hospitalization were compared. Operative times were used to extrapolate learning curves and evaluate the effects of changes in faculty using CUSUM charts. A propensity score matching analysis was performed to reduce differences between cohorts regarding both preoperative characteristics and intraoperative findings. A total of 1173 patients undergoing LA for acute appendicitis were included, of whom 521 (45%) in the TRN group and 652 (55%) in the ATT group. No significant differences were found between the two groups in terms of complication rates, operative times and length of hospital stay. However, CUSUM chart analysis showed decreased operating times in the TRN group. Operative times improved more quickly for advanced cases. The results of this study indicate that LA can be performed by trainees without detrimental effects on clinical outcomes, procedural safety, and operative times. However, the learning curve is longer than previously acknowledged.

Drains, Germs, or Steel: Multidisciplinary Management of Acute Colonic Diverticulitis.

The medical and surgical management of uncomplicated diverticulitis has changed over the last several years. Although immunocompetent patients or those without comorbidities can be treated with antibiotics as an outpatient, the efficacy of high-fiber intake or drugs such as mesalamine or rifaximin is not yet clearly established in the treatment of acute episodes and in the prevention of recurrences. On the other hand, the choice between antibiotic treatment and percutaneous drainage is not always obvious in diverticulitis complicated by abscess formation, especially for larger abscesses; although the results of studies comparing the two approaches remain controversial, surgery must be pursued for abscesses > 8 cm. For emergency surgery, the debate is still ongoing regarding laparoscopic lavage and surgical resection followed by primary anastomosis, since for both approaches the published reports are not in agreement regarding possible benefits. Therefore, these approaches are recommended only for selected patients under the care of experienced surgeons. Also, the contribution of elective surgery toward the overall approach has been revised; currently, it is reserved primarily for patients with a high risk of recurrence and whenever more conservative treatments were not effective.

A systematic review on the cost evaluation of two different laparoscopic surgical techniques among 996 appendectomies from a single center.

Acute appendicitis is one of the main indications for urgent surgery representing a high-volume procedure worldwide. The current spending review in Italy (and not only in this country) affects the health service and warrants care regarding the use of different surgical devices. The aim of our study is to perform a cost evaluation, comparing the use of endoloops and staplers in complicated acute appendicitis (phlegmonous and gangrenous), taking into consideration the cost of the device in relation to the management of any associated postoperative complications. We retrospectively evaluated 996 laparoscopic appendectomies of adult patients performed in the Emergency General Surgery-St. Orsola University Hospital in Bologna (Italy). Surgical procedures together with the related choice of using endoloops or staplers were performed by attending surgeons or resident surgeons supervised by a tutor. A systematic review was performed to compare our outcomes with those reported in the literature. In our experience, the routine use of endoloop leads to a real estimated saving of 375€ for each performed laparoscopic appendectomy, even considering post-operative complications. Comparing endoloop and stapler groups, the total number of complications is significantly lower in the endoloop group. Our systematic review confirmed these findings even if the superiority of one technique has not been proved yet. Our analysis shows that the routine use of endoloop is safe in most patients affected by acute appendicitis, even when complicated, and it is a cost-effective device even when taking into consideration extra costs for potential post-operative complications.

Proteogenomic biomarkers in colorectal cancers: clinical applications.

INTRODUCTION: Colorectal cancer (CRC) is one of the leading cancers in terms of incidence and mortality, rate requiring a multidisciplinary approach. The discovery of specific CRC biomarkers has caused a paradigm shift in its clinical management. AREAS COVERED: The aim is to illustrate the possible clinical applications of CRC biomarkers through an updated literature review (from 2015 to 2020) based on the PubMed database. A relationship between cancer localization and genetic profile has been identified. Nowadays, the tumor markers are largely used to select patients that could really benefit from a specific type of adjuvant therapy, in order to optimize treatment programs, especially in metastatic patients. This review highlights both CRC biomarkers' advantages and critical issues. EXPERT OPINION: New biomarker discoveries allow to set noninvasive tests that could increase patient's compliance with therapy. They also permit a cost-effective early diagnosis, as well as patient-tailored treatments, improving the overall survival. The CRC biomarkers could also have a prognostic value, and usually, they are included in follow-up programs. However, despite the continuous progression of new technologies, their clinical validation is still debated. In this context, additional clinical studies are still necessary to identify, among potential markers, the most effective ones.

Obstructing Left-Sided Colonic Cancer: Is Endoscopic Stenting a Bridge to Surgery or a Bridge to Nowhere?

For the 8-29% colorectal cancers that initially manifest with obstruction, emergency surgery (ES) was traditionally considered the only available therapy, despite high morbidity and mortality rates and the need for colostomy creation. More recently, malignant obstruction of the left colon can be temporized by endoscopic placement of a self-expanding metallic stent (SEMS), used as bridge to surgery (BTS), facilitating a laparoscopic approach and increasing the likelihood that a primary anastomosis instead of stoma would be used. Despite these attractive outcomes, the superiority of the BTS approach is not clearly established. Few authors have stressed the potential cancer risk associated with perforations that may occur during endoscopic stent placement, facilitating neoplastic spread and negatively impacting prognosis. For this reason, the current literature focuses on long-term oncologic outcomes such as disease-free survival, overall survival and recurrence rate that do seem not to differ between the ES and BTS approaches. This lack of consensus has spawned differing and sometimes discordant guidelines worldwide. In conclusion, 20 years after the first description of a colonic stent as BTS, the debate is still open, but the growing number of articles about the use of SEMS as a BTS signifies a great interest in the topic. We hope that these data will finally converge on a single set of recommendations supporting a management strategy with well-demonstrated superiority.

Laparoscopic cholecystectomy: which predicting factors of conversion? Two Italian center's studies.

BACKGROUND: Laparoscopic cholecystectomy represents the gold standard technique for the treatment of lithiasic gallbladder disease. Although it has many advantages, laparoscopic cholecystectomy is not risk-free and in special situations there is a need for conversion into an open procedure, in order to minimize postoperative complications and to complete the procedure safely. The aim of this study was to identify factors that can predict the conversion to open cholecystectomy. METHODS: We analyzed 1323 patients undergoing laparoscopic cholecystectomy over the last five years at St. Orsola University Hospital-Bologna and Umberto I University Hospital-Rome. Among these, 116 patients (8.7%) were converted into laparotomic cholecystectomy. Clinical, demographic, surgical and pathological data from these patients were included in a prospective database. A univariate analysis was performed followed by a multivariate logistic regression. RESULTS: On univariate analysis, the factors significantly correlated with conversion to open were the ASA score higher than 3 and the comorbidity, specifically cardiovascular disease, diabetes and chronic renal failure (P<0.001). Patients with a higher mean age had a higher risk of conversion to open (61.9±17.1 vs. 54.1±15.2, P<0.001). Previous abdominal surgery and previous episodes of cholecystitis and/or pancreatitis were not statistically significant factors for conversion. There were four deaths in the group of converted patients and two in the laparoscopic group (P<0.001). Operative morbility was higher in the conversion group (22% versus 8%, P<0.001). Multivariate analysis showed that the factors significantly correlated to conversion were: age <65 years old (P=0.031 OR: 1.6), ASA score 3-4 (P=0.013, OR:1.8), history of ERCP (P=0.16 OR:1.7), emergency procedure (P=0.011, OR:1.7); CRP higher than 0,5 (P<0.001, OR:3.3), acute cholecystitis (P<0.001, OR:1.4). Further multivariate analysis of morbidity, postoperative mortality and home discharge showed that conversion had a significant influence on overall post-operative complications (P=0.011, OR:2.01), while mortality (P=0.143) and discharge at home were less statistically influenced. CONCLUSIONS: Our results show that most of the independent risk factors for conversion cannot be modified by delaying surgery. Many factors reported in the literature did not significantly impact conversion rates in our results.

Paratesticular Mesenchymal Malignancies: A Single-Center Case Series, Clinical Management, and Review of Literature.

Background: Primary soft tissue sarcomas arising from the male urinary and genital tract are rare tumors, only accounting for 1% to 2% of all malignancies of the genitourinary tract. Clinical management of advanced disease is lacking in standardized recommendations due to the rarity of the disease. To date, complete and extensive surgery represents the only curative and standardized approach for localized disease, while the impact of retroperitoneal lymphadenectomy and adjuvant treatments on clinical outcomes are still unclear. Similarly, a standardized systemic treatment for advanced metastatic disease is still missing. Cases Presentation: Four out of 274 patients have been identified in our sarcoma population. The mean age was 54 years (range = 45-73). The histotypes showed liposarcoma in 2 cases and leiomyosarcoma in the remaining 2 cases. In all 4 cases, the disease was localized at presentation, patients underwent complete surgery, and no adjuvant treatments were done. Three cases presented a recurrence of disease at a mean follow-up of 86 months (range = 60-106 months), more than 7 years. Two cases were treated with a second surgery and chemotherapy and 1 case only with chemotherapy. Discussion and Conclusions: Sharing data about clinical management of paratesticular mesenchymal tumors is a key issue due to the rarity of this tumor's subtype. In this article, we report the clinical history of 4 patients affected by paratesticular mesenchymal tumor. In particular, main issues of interest are the decision of postoperative treatment and systemic treatment at time of disease recurrence.

Factors affecting the number of lymph nodes retrieved after colo-rectal cancer surgery: A prospective single-centre study.

BACKGROUND: The number of harvested lymph nodes (LNs) in colorectal cancer surgery relates to oncologic radicality and accuracy of staging. In addition, it affects the choice of adjuvant therapy, as well as prognosis. The American Joint Committee on Cancer defines at least 12 LNs harvested as adequate in colorectal cancer resections. Despite the importance of the topic, even in high-volume colorectal centres the rate of adequacy never reaches 100%. The aim of this study was to identify factors that affect the number of harvested LNs in oncologic colorectal surgery. MATERIALS AND METHODS: We prospectively collected all consecutive patients who underwent colorectal cancer resection from January 1st 2013 to December 31st 2017 at Emergency Surgery Unit St Orsola University Hospital of Bologna. RESULTS: Six hundred and forty-three consecutive patients (382 elective, 261 emergency) met the study inclusion criteria. Emergency surgery and laparoscopic approach did not have a significant influence on the number of harvested LNs. The adequacy of lymphadenectomy was negatively affected by age >80 (OR 3.47, p < 0.001), ASA score ≥3 (OR 3.48, p < 0.001), Hartmann's or rectal resection (OR 3.6, p < 0.001) and R1-R2 resection margins (OR 3.9, p = 0.006), while it was positively affected by T-status ≥3 (OR 0.33 p < 0.001). CONCLUSION: Both the surgical technique and procedure regimen did not affect the number of lymphnodes retrieved. Age >80 and ASA score ≥3 and Hartmann's procedure or rectal resection showed to be risk factors related to inadequate lymphadenectomy in colorectal cancer surgery.

Cholecystectomy for acute cholecystitis in octogenarians: impact of advanced age on postoperative outcome.

BACKGROUND: The number of surgical operations in elderly patients is increasing due to the aging demographics of western populations. The aim of the present study was to investigate the peri-operative outcome of octogenarian patients undergoing cholecystectomy for acute cholecystitis. METHODS: We performed a retrospective analysis including all patients who underwent cholecystectomy for acute cholecystitis from January 2013 to December 2017. Records were collected prospectively from two centers: 1) Unit of Emergency Surgery, St. Orsola University Hospital, Alma Mater Studiorum University, Bologna; 2) "Advanced Surgical Technologies" Department of Surgical Sciences, Umberto I University Hospital, La Sapienza University, Rome. Patients were divided by age (≥ or <80 years) and peri-operative outcomes were compared. RESULTS: During the study period, 464 patients were operated for acute cholecystitis in the two centers. Sixty-three (14%) patients were octogenarians (group 1) and median age was 84.8±3.9 years. Four hundred and one patients (86%) were younger than 80 years (group 2) with median age of 55.3±15.3 years. Forty-four per cent of group-1 patients underwent laparoscopic cholecystectomy versus 81% of the younger group (P<0.01). Elderly patients had a higher percentage of overall complications (25% vs. 9%; P=0.03) and a longer median postoperative length of stay (7.2±6.8 vs. 4.6±7.7; P=0.04). Overall mortality was 1%: two patients died in group-1 and one in group-2 (P=0.50). However, on multivariate analysis age older than 80 years was not found to be an independent risk factor for postoperative morbidity and mortality. CONCLUSIONS: The results of this study suggest that cholecystectomy for acute cholecystitis in octogenarians is a relatively safe procedure with an acceptable risk of complications and a postoperative hospital stay comparable to younger ones.

The Multidisciplinary Management of Acute Complicated Diverticulitis.

BACKGROUND: Acute complicated diverticulitis (ACD) is an important and increasing issue in Western countries that leads to a significant impact and burden for patients, but also for the society due to its effects on hospital costs. In recent years, essential progression has been made regarding the research and implementation of novel or improved treatment strategies for the various disease entities of ACD. Much debated topics in the multidisciplinary approach of patients with ACD, such as the choice for nonoperative treatment options, the role of percutaneous drainage for diverticular abscesses, the role of laparoscopic lavage for perforated diverticulitis with purulent peritonitis, and the role of sigmoidectomy with primary anastomosis for patients with perforated diverticulitis, require clinicians to attentively follow and participate in these discussions. SUMMARY: The aim of this review article is to provide clinicians with a structured overview of the recent literature on the multidisciplinary management of complicated diverticulitis by a panel of experts on the topic. By performing an extensive literature search in the online medical databases MEDLINE (Ovid) and Embase, insights into nonoperative treatment, percutaneous drainage, minimally invasive and open surgical treatment of ACD are provided. Furthermore, a comprehensive algorithm for the treatment of ACD has been developed. KEY MESSAGES: Accurate patient evaluation and selection based on patient and disease characteristics is of paramount importance to determine the appropriate treatment strategy for patients with complicated diverticulitis. The presence of an experienced surgeon with advanced skills in laparoscopic emergency colorectal surgery is crucial for the treatment of patients with perforated diverticulitis in order to properly evaluate, select and treat patients suitable for nonoperative or operative treatment with an open or laparoscopic approach.

Right-sided acute diverticulitis: A single Western center experience.

INTRODUCTION: Right sided diverticular disease is a rare condition in Western countries whereas is common amongst Asian population. The aim of this study is to evaluate options and outcomes for the treatment of right colonic diverticulitis. METHOD: We included only patients undergoing surgery with right colon diverticulitis (RCD) proven at histological specimen examination from September 2011 to December 2016. RESULTS: We performed 18 operations for RCD. Age was lower compared to left sided disease (49 ± 16 vs 67 ± 14; P < 0.001). Three patients were Asian (16.7%). RCD was diagnosed preoperatively in 8 cases (44.4%), whereas appendicitis was suspected in 9 cases (50%) and neoplasm in one (5.6%). We performed resection with anastomosis in 13 patients (72.2%) and in 5 cases we performed a diverticulectomy. Laparoscopy was performed in 14 cases (77.8%). Postoperative morbidity occurred in 3 patients (16.7%; grade 2 or 3a according to Clavien-Dindo) with no mortality. No postoperative events occured after diverticulectomy with shorter hospital stay (4 ± 1.5 vs 11 ± 13; P = 0.022), as no recurrence or need for elective surgery after a mean follow-up of 20 months. CONCLUSION: RCD is a rare but not irrelevant condition. Minimally invasive surgery is often feasible and complication rate is low. In selected patients, diverticulectomy can be a valid alternative to treat this condition providing improved postoperative results.

Impact of octogenarians on surgical outcome in colorectal cancer.

AIM: Colorectal cancer's (CRC) incidence occupies the second place among malignant tumours in men and the third place in women. The aging of the population raises new questions on the management of CRC in octogenarian patients. The objective of this study was to assess the influence of age (≥80) on treatment and surgical outcome of colorectal cancer. METHOD: In the period between October 1995 and April 2014, a total of 1397 patients underwent emergency and elective surgical interventions for CRC; the first group (Group-Older - GO) was composed of 291 patients 80 years or older (20.9%, of which 46.4% were male). The second group (Group-Younger - GY) included 1106 patients younger than 80 years (79,1%, 57.7% males). RESULTS: Significant differences between the two groups were observed regarding sex (p = 0.001), number of comorbidities (p = 0.001), ASA classification (p < 0.001), emergency presentation (p < 0.001), site of tumor (p = 0.010), need of intraoperative blood transfusions (p < 0.001), 30-days mortality (p < 0.001), 90-days mortality (p < 0.001) and morbidity in accordance with Clavien-Dindo classification (p < 0.001). When combining both elective and emergency procedures, multivariate logistic regression analysis showed that advanced age (≥80 years old) was an independent predictor factor of 30-days mortality (p = 0.023, OR = 2.23) and morbidity (p = 0.088, OR = 1.31), while it was not predictive of 90-days mortality. When considering only elective colorectal surgery, octogenarian age was not found to be a predictive factor of 30-day and 90-day mortality, but predictive of postoperative morbidity. CONCLUSION: Old age (≥80) does not represent a contraindication to CRC elective surgical treatment, in emergency procedures it is associated with an increased risk of postoperative morbidity and mortality.

Laparoscopic appendectomy: Which factors are predictors of conversion? A high-volume prospective cohort study.

Appendicitis represents one of the most frequent condition requiring surgery. In Italy almost 0.2% of the population will be affected by acute appendicitis every year. Laparoscopic appendectomy (LA) has gained acceptance over the past years and despite several meta-analyses, randomized studies and retrospective studies have been conducted, the indications and results are still conflicting especially in cases of complicated appendicitis. The aim of our study is to evaluate which factors are related to conversion to open appendectomy (OA) during laparoscopic appendectomy (LA). MATHERIALS AND METHODS: From September 2011 to May 2013, appendectomy for acute appendicitis was performed on 434 patients in our Surgical Unit at S. Orsola-Malpighi Hospital, Bologna, Italy. Of these, 369 patients (85%) underwent LA. The clinical, demographic, surgical and pathological data of these patients were included in a prospective database. To note, only laparoscopic appendectomies were considered to be included in the analysis. The following factors were analyzed in order to identify which were associated with the conversion: age, sex, body mass index (BMI), previous abdominal surgery, comorbidities, clinical and laboratory parameters including Alvarado score, PCR, intraoperative findings such as anatomy and degree of inflammation. During our study period, laparoscopic appendectomies were performed by different surgeons both residents and attending surgeons. The decision to convert the intervention in an open procedure was taken by the individual surgeon. Regarding the postoperative period, were considered the time of hospitalization and related costs, time of oral intake of liquid and solid, time of passage of stool, readmissions and reoperations. RESULTS: At univariate analysis, the factors significantly related to the conversion were the presence of comorbidities (p < 0.001) and, among these, the presence of arterial hypertension (p = 0.006) or other cardiovascular diseases (p = 0.031) and the history of previous abdominal surgery (p = 0.023). Patients with higher mean age (33.9 ± 15.4 vs. 46.0 ± 19.3, p = 0.001) and higher body mass index (BMI) (23.5 ± 4.3 vs 25.8 ± 4.9 kg/m(2), p = 0.006) had a higher risk of conversion. Multivariate analysis finally showed that factors significantly related to the conversion were the presence of comorbidities (p = 0.029), the presence of an appendiceal perforation (p = 0.003), a retrocecal appendix (p = 0.004), the presence of appendicular abscess (p = 0.023) and the presence of diffuse peritonitis (p = 0.008). CONCLUSION: The majority of patients with acute appendicitis can be successfully managed with laparoscopy. We found that the only preoperative independent factor related to conversion during laparoscopic appendectomy is the presence of comorbidities. Nevertheless surgeons should take into account that presence of peri-appendicular abscess and diffuse peritonitis are both independently related not only to higher rate of conversion but also to higher risk of postoperative complication.

Biochemical alterations from normal mucosa to gastric cancer by ex vivo magnetic resonance spectroscopy.

BACKGROUND AND AIMS: The metabolic profile and morphologic aspects of normal and pathologic human gastric mucosa were studied. The aim of the present research was the application of ex vivo high-resolution magic angle spinning magnetic resonance spectroscopy (HR-MAS MRS) to the human gastric tissue to get information on the molecular steps involved in gastric carcinogenesis and the identification of biochemical markers useful for the development of in vivo MRS methodologies to diagnose gastric pathologies in clinical situations. METHODS: Twelve normal subjects, five with autoimmune atrophic gastritis, five with Helicobacter pylori infection, and five with adenocarcinoma were examined. Ten biopsies were taken during endoscopy from each patient. Specimens from carcinoma were also obtained during gastrectomy. Of the 10 biopsies, 4 were used for histologic evaluation, 4 were fixed in glutaraldehyde and processed for transmission and scanning electron microscopy, and 2 were immersed in liquid nitrogen and stored at -85 degrees C for monodimensional and bidimensional ex vivo HR-MAS MRS analysis. RESULTS: Ex vivo HR-MAS MRS identified glycine, alanine, free choline, and triglycerides as possible molecular markers related to the human gastric mucosa differentiation toward preneoplastic and neoplastic conditions. Ultrastructural studies of autoimmune atrophic gastritis and gastric adenocarcinoma revealed lipid accumulations intracellularly and extracellularly associated with a severe prenecrotic hypoxia and mitochondria degeneration. CONCLUSIONS: This is the first report of synergic applications of ex vivo HR-MAS MRS and electron microscopy in studying the human gastric mucosa differentiation. This research provides useful information about some molecular steps involved in gastric carcinogenesis. The biochemical data obtained on gastric pathologic tissue could represent the basis for clinical applications of in vivo MRS.