A patient with Intestinal Aspergillosis caused by Endoscopic Submucosal Dissection operation

Gastrointestinal Aspergillosis (GA) is rarely invasive aspergillosis. We describe the first case of primary invasive gastric aspergillosis arising after endoscopic submucosal dissection in an immunocompetent diabetic patient, apparently triggered by routine home cleaning, and progressing rapidly to fatal systemic dissemination.

GA: Gastrointestinal Aspergillosis; IA: Invasive Aspergillosis; GI: Gastrointestinal; ESD: Endoscopic Submucosal Dissection; DM: Diabetes Mellitus; CRP: C-Reactive Protein; NK: Natural Killer; mNGS: metagenomic Next-Generation Sequencing; ANA: Antinuclear Antibodies; ANCA: Antineutrophil Cytoplasmic Antibodies; SHLS: Hemophagocytic-Like Syndrome; ICU: Intensive Care Unit; PCR: Polymerase Chain Reaction; HSCT: Hematopoietic Stem Cell Transplantation; BAL: Bronchoalveolar Lavage Fluid; IAmB: Liposomal Amphotericin B

Invasive Aspergillosis (IA), generally considered an opportunistic infection in immunocompromised hosts, is associated with high morbidity and mortality. IA typically involves the lungs, but may also infect the nasal sinuses, central nervous system, and rarely Gastrointestinal (GI) system. Wherein, the small intestine is its most afected organ [1]. Clinical manifestations of gastrointestinal aspergillosis are nonspecifc, such as abdominal pain, diarrhea, hemorrhage and only occasionally it presents as an acute abdomen due to intestinal obstruction and perforation [2]. The digestive tract may represent a portal of entry for Aspergillus species when the mucosal barrier in pathologic conditions such as gastric ulcers and severe gastritis [3,4]. We are reporting a rare case of a GA in a diabet patient following Endoscopic Submucosal Dissection (ESD) operation on the stomach. Invasive gastrointestinal aspergillosis developing after ESD is exceedingly rare, and each new case redefines our understanding of both the pathogenesis and the preventive measures required after gastric mucosal resection.

A 54-year-old male with a history of type II Diabetes Mellitus (DM) was on oral hypoglycemic medications for glycemic control. On November 16th in 2023, the patient had an ESD operation for size 2*2.5cm polypoid changes in the pylorus in the local hospital. After discharge, the patient primarily consumed liquid diet, had poor appetite, the patient did not regularly take hypoglycemic medications and monitor blood glucose. Coincidentally, during this period, his family was involved in household relocation and cleaning, which exposed him to moldy books and bedding. The 14th day of postoperative ESD, the patient’s temperature was 38.5℃ and felt fatigue, accompanied by abdominal distension and rash, non-pruritic and non-painful rash on the abdomen.

Physical examination revealed scattered red skin rash over the body, no signs of hepatomegaly, and no palpable superficial lymph nodes.

Laboratory tests showed a white blood cell count of 1.0*10⁹/L, hemoglobin level of 10g/dL, platelet count of 32×10⁹/L, C-Reactive Protein (CRP) level of 54.47mg/dL, blood urea nitrogen level of 18.54mmol/L, serum creatinine concentration of 162.1umol/L, aspartate aminotransferase level of 311IU/L, alanine transaminase level of 743IU/L, soluble CD25 level of 2311U/ml, ferroprotein 1369.6ng/ml, Natural Killer (NK) cell activity decreased to 2.9% (normal >4%), fasting blood glucose 11.64mmol/L, the galactomannan serum concentration was positive at 115 (normal rang 1-60). Blood metagenomic Next-Generation Sequencing (mNGS) revealed presence of Aspergillus species with 7 sequence counts, Penicillium species with 1 sequence count (accession number OMIX011053).

Bone marrow examination indicated a slight reduction in nuclear cell count, granulocytic hyperplasia with left shift and toxic changes, decreased erythroid cell growth, and a high proportion (38%) of mature lymphocytes with occasional immature lymphocytes. Phagocytic cells and a small amount of hemophagocytosis were observed. There is no lymphocyte tumor proliferation in patient’s Bone marrow puncture pathology immunohistochemistry. Negative laboratory test results included dengue fever antibodies, ADAMTS antibodies, flow fever antibodies, Antinuclear Antibodies (ANA), Antineutrophil Cytoplasmic Antibodies (ANCA), and related anti-nuclear antibodies series.

Diagnosis of the patient: 1) Sepsis with Hemophagocytic-Like Syndrome (SHLS), 2) Rash. The patient was administered methylprednisolone, immunoglobulin, and received combination therapy with imipenem-cilastatin and caspofungin for infection control.

On the 9th day of onset, the patient developed unconsciousness, shock, hyperkalemia, and metabolic acidosis, the patient was transferred to the Intensive Care Unit (ICU) of our hospital for mechanical ventilator therapy and continuous renal replacement therapy. Continue with imipenem-cilastatin and caspofungin, and after six days of treatment, the condition improved and the patient was transferred out of ICU.

On the 19th day of onset, the patient developed severe abdominal pain. Abdominal CT scan with contrast showed possible local ischemia, perforation, and peripheral free gas in the descending colon. The small bowel on the left side showed wall swelling and possible ischemia. The left kidney exhibited irregular patchy hypo-enhancement, suggestive of ischemia. An exploratory laparotomy was performed under general anesthesia. During the operation, we found the whole small intestine was explored to diffuse intestinal dilation, the descending colon was blackened with necrosis, the proximal intestine was dilated, the serosa was ruptured. The left colon was excised, and the proximal transverse colon was stomated in the abdominal wall.

Laboratory examination of the abdominal drainage fluid showed 30 red blood cells/μl and 40 nucleated cells/μl. The smear indicated a large number of Gram positive (G+) cocci, the result of ascites culture: Enterococcus faecium (Group D) µg/ml and Klebsiella pneumoniae. Pathological examination of the resected specimen (left colon resection) revealed chronic inflammation with necrosis and fungal infection (Morphologically, there were a tendency towards Aspergillus). Immunity staining included: acid-fast stain (-), Gomori’s methenamine silver stain (+), mucin stain (+), PAS stain (+), fungal immunofluorescence (+), and acid-fast fluorescence (-) (Figure 1).

Figure 1: Periodic acid-Schiff stains (original magnification ×400) of resected colon specimen show septated fungal hyphae with acute angle branching, morphologically consistent with aspergillus species.

Post-surgery, the patient exhibited high levels of inflammatory markers, low platelet count, and abnormal coagulation function (Figure 2). On the 5th day after surgery (the 24th day of onset), the patient showed presence of Aspergillus infection on the lung CT scan (Figure 3), and moderate growth of Aspergillus fumigatus in sputum culture. On the 6th day after surgery (25th day of onset), the patient developed skin lesions on the left side of the abdomen (not at the surgical incision). Necrotic skin tissue began to peel off, and within 3 days, the infected skin area doubled (Figure 4). The resected specimen showed septated fungal hyphae with acute angle branching, suggesting aspergillus species under the microscope (Figure 5).

Figure 2: Post-surgery, the patient exhibited high levels of inflammatory markers, low platelet count, and abnormal coagulation function.

Figure 3: Chest Computed Tomography (CT) scans showed multiple fungal infections in both sides.

Figure 4: The skin on the left abdomen began to skin necrosis, and the infected skin area doubled in size from 10*10 cm to 20*20 cm.

Figure 5: Necrotic skin tissue smear under a microscope (10× original magnifcation, Aspergillus mycelium structure matches, with branching at a 45° angle).

The patient developed severe sepsis. Despite the patient received combination therapy with daptomycin, imipenem-cilastatin, liposomal amphotericin B and voriconazole, the patient's condition rapidly deteriorated and eventually died.

Invasive aspergillosis occurs in individuals with chronic use of corticosteroids or immunosuppressive treatments, those experiencing prolonged neutropenia, patients with hepatic cirrhosis, chronic granulomatous diseases, or diabetics with hyperglycemia. Diabetics with hyperglycemia have a compromised immune response [5,6]. GA is a rare but severe form of invasive fungal infection primarily affecting immunocompromised individuals. GA is most commonly seen in patients with hematologic malignancies, particularly those who have undergone Hematopoietic Stem Cell Transplantation (HSCT), solid organ transplantation, or are on long-term steroid treatment [7-9]. In our case, as a diabetic, diet primarily consisted of liquid foods due to the ESD procedure. This led to a decreased appetite and irregular dietary habits, resulting in irregular administration of hypoglycemic medications. Considering the patient's recent poor blood sugar control, their resistance was likely diminished. Hyperglycemia in DM impairs immune responses including phagocytosis and complement function, which may permit bacterial or fungal colonization of skin or mucosa and may sometimes be associated with systemic infections [10,11]. In a review presented by Eggimann P, et al. [12] the authors propose that, in addition to aerial transmission, gastrointestinal invasion should also be considered as a potential entry route for invasive aspergillus species. They theorize that Aspergillus spores may encounter favorable conditions for proliferation within the ulcers present on the mucous surfaces of the digestive tract. There have been cases of GA reported, which propose an oral entry point due to the consumption of contaminated food [13]. Given that the patient did not exhibit any respiratory symptoms or radiological signs of aspergillosis in the lungs at the onset of the disease, we considered that the patient's infection with GA may have also entered through the oral entry point into the stomach. The Aspergillus spores originated from the dust stirred up during the home relocation and cleaning process, which included spores from bedding and books. These spores, after being ingested with food, colonized on the ulcerated gastric mucosa, leading to a subsequent systemic infection (gastrointestinal tract, skin and lungs).

The pathogenesis of GA involves tissue necrosis due to vascular invasion by Aspergillus, leading to complications such as ileus and intestinal perforation. This vascular invasion is a hallmark of invasive aspergillosis and contributes to the high rate of surgical intervention in affected patients. The clinical presentation of GA is diverse and non-specific, often including symptoms such as abdominal pain, diarrhea, vomiting, and dysphagia. lIeus, acute peritonitis, and gastrointestinal bleeding are also observed. The non-specific nature of these symptoms can lead to misdiagnosis. A highclinical suspicion is needed to consider testing for aspergillosis (for example, by testing for antigens like Galactomannan (GM) and beta (1, 3)-D-glucan) [14,15].

The mortality rate in patients with GA is high, with over half of the patients dying within a short period after diagnosis. This high mortality is attributed to the difficulty in diagnosis, the severity of the disease, and the immunocompromised state of the patients. Systematic differentiation from other hyaline moulds-namely Mucorales, Fusarium spp., Scedosporium spp., and Paecilomyces spp.-is therefore imperative. When necrotic gastrointestinal ulcers or segmental ischemic lesions are encountered in an immunocompromised host, the differential diagnosis must be approached systematically. Distinguishing invasive aspergillosis from other hyaline moulds is critical because treatment and prognosis differ. On haematoxylin–eosin sections, Aspergillus spp. display uniform, septate hyphae 3-6 µm in diameter with regular, acute-angle (≈45°) dichotomous branching and prominent angio-invasion, resulting in thrombosis and wedge-shaped infarcts. In contrast, Mucorales exhibit broad (6-25 µm), ribbon-like, predominantly non-septate hyphae with right-angle (90°) branching, whereas Fusarium spp. are narrower, septate, with irregular acute-angle branching and often show yeast-like oval conidia in tissues. Scedosporium and Paecilomyces spp. have intermediate-width septate hyphae that may be pigmented and require culture or molecular confirmation. Immunohistochemistry using a monoclonal antibody directed against Aspergillus galactomannan (clone JF5) has >90 % sensitivity and specificity for discriminating Aspergillus from these mimics on formalin-fixed tissue. In our patient, Grocott Methenamine-Silver (GMS) and Periodic-Acid–Schiff (PAS) stains revealed septate, 45°-branching hyphae within necrotic sub-mucosal vessels; Fontana-Masson melanin stain was negative, excluding dematiaceous moulds. Subsequent anti-Aspergillus JF5 immunohistochemistry was strongly positive, while a pan-Mucorales antibody panel remained negative, confirming the histologic diagnosis.

The gold standard for diagnosis is a combination of microbiological identification, such as fungus culture, and histopathological examination, which can reveal the characteristic 45-degree branching hyphae of Aspergillus. However, other hyaline molds can have similar appearances, necessitating confirmation through culture or Polymerase Chain Reaction (PCR). The use of GM in serum and Bronchoalveolar Lavage fluid (BAL) serves as an accurate biomarker for the diagnosis of IA. In our case, the etiological examination of the patient's serum revealed the presence of Aspergillus species, which, although not in high quantities, indeed represents the gold standard for confirmation.

Regarding the treatment of IA, the guidelines recommend the use of voriconazole and Liposomal Amphotericin B (IAmB) are first-line treatment options. Current evidence and guidelines published in 2022–2024 continue to recommend voriconazole and liposomal amphotericin B as first-line therapy for invasive aspergillosis, with isavuconazole as an acceptable alternative. Voriconazole has broad antifungal activity against aspergillus species and has been proven to be highly effective in treating invasive aspergillosis with improved survival rates [16,17]. For patients who do not respond to or cannot tolerate first-line treatment, caspofungin and other echinocandins are effective second-line options. Echinocandins inhibit the synthesis of 1,3-β-D-glucan, an essential component of the fungal cell wall, and exhibit potent in vitro and in vivo antifungal activity against Aspergillus and Candida species [18,19]. For patients with esophageal, gastrointestinal, and hepatic aspergillosis, it is recommended to treat with voriconazole and consult for surgery to prevent complications such as bleeding, perforation, obstruction, or infarction. In our case, the primary reason for the failure was the initial lack of awareness of the systemic aspergillosis infection. By the time the intestinal pathology results confirmed the aspergillosis and targeted antifungal treatment was initiated, the patient's systemic infection had already progressed to a severe stage [20,21].

Our report illustrates the case of a patient after ESD that developed a very rare entity which led to his death. We suggest that IA should be considered in critically ill patients with non-classical risk factors for diagnosis and appropriate treatment because it is no longer only a disease of immune compromised hosts. In addition, primary or isolated GA may also occur in the immune competent hosts without classical risk factors.

This case illustrates that the occurrence of GA after ESD surgery is rare, but the risk of death is significant. For such high-risk patients, it is crucial to make a timely diagnosis and provide prompt treatment.

TT Lou and XLF designed and supervised the study; TT Lou and TT Liu enrolled patients and took care of the patients; TT Lou collected clinical data; TT Lou and XLF analysed the data and wrote and revised the manuscript; and MJZ contributed to figure proofreading.

Not applicable.

All data associated with this study are present in the paper.

Not applicable.

Written informed consents for publication of the clinical details were obtained from the patients or their first-degree relatives.

The authors declare that they have no conflicts of interest.

The data reported in this paper have been deposited in the OMIX, China National Center for Bio information / Beijing Institute of Genomics, Chinese Academy of Sciences (https://ngdc.cncb.ac.cn/omix accession No.OMIX011053).

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