A rare case of gastric mucormycosis in an immunocompetent patient

We report the case of a 23-year-old immunocompetent patient who presented at the emergency department of a Brazilian hospital with epigastric pain and fever. After an investigation that included a computed tomography scan and upper gastrointestinal endoscopy with biopsy, a diagnosis of mucormycosis was established. The patient exhibited favorable progress after surgery and antifungal therapy. Mucormycosis is a rare condition that usually affects immunocompromised patients, with a high mortality rate of up to 85%. Correct diagnosis and fast initiation of therapy are required to ensure improved patient prognosis.


INTRODUCTION
Mucormycosis is a rare, opportunistic fungal infection led by fungal agents within the order Mucorales 1 ; occurs almost solely in immunocompromised hosts, such as patients with diabetes mellitus (which is a major predisposing factor), burns, malnutrition, leukemia, lymphoma, septicemia, renal disease, and following long-term treatment with steroids and antibiotics; and is associated with high mortality rates [1][2][3] .
Nevertheless, 19% of patients have no underlying condition at the time of infection.Patients with human immunodeficiency virus (HIV) infection represent only 2% of those with zygomycosis 4 .Based on autopsy data, the prevalence is 1-5 cases per 10,000 individuals with hematological neoplasms, which is far less prevalent than invasive Candida or Aspergillus infections 4 .

CASE REPORT
A 23-year-old woman presented with a 1-month history of diffuse abdominal pain, which was predominantly epigastric, in addition to abdominal distension, vomiting, and fever.The patient reported normal feeding.Also, refers previous tuberculosis, with complete treatment; no other previous diseases; and no alcoholism, smoking, or illicit drug use.In the following investigation, contrast-enhanced radiography revealed a hypotonic stomach with excess of fluid retention and difficulty in emptying (Figure 1).Computed tomography (CT) with oral contrast showed diffuse gastric distension associated with diffuse parietal thickening, and heterogeneous impregnation by contrast, identifying the gastric antrum lumen containing liquid contents (Figure 1 and Figure 2).The stomach exhibited inferior displacement of the intestine and transverse colon loops (Figure 2).
Upper gastrointestinal endoscopy revealed enanthematic gastritis of slight intensity.Based on the anatomopathological evaluation, the gastric segment measured 25.0×12.0×6.0cm and was smooth, serous, gleaming, and brownish in color.The mucosa was brownish in color with pre-clearing and a firm consistency, with thickened regions up to 5.0cm.The biopsy demonstrated chronic granulomatous and suppurative   gastritis, associated with marked fibrosis of the gastric wall, presenting voluminous zygomycosis hyphae (Figure 3).
The patient underwent total gastrectomy, with lymphadenectomy and esophagoenteroanastomosis, and treatment containing amphotericin B. Her clinical evolution during 6 weeks of treatment was positive, and she was discharged after being oriented to the outpatient follow-up.The patient received 2.8 grams of amphotericin B throughout the treatment period.
In gastrointestinal involvement, the most frequently compromised organ is the stomach (58%), followed by the colon (32%), small intestine, and esophagus [1][2][3]5 . Th incidence is increasing, and the diagnosis carries a significant mortality rate of up to 85% due to perforation and massive bleeding 1,2,4 .
The symptomatology of gastrointestinal mucormycosis varies from fever, nausea, non-specific abdominal pain, and vomiting to hematemesis, melena, hematochezia, or gastrointestinal perforation 1 .The diagnosis is frequently confirmed histopathologically based on biopsy of the suspected area during surgery or endoscopy 1 .CT can be instrumental in identifying multi-organ involvement. 6The diagnosis of gastrointestinal mucormycosis can be established based on endoscopic biopsy of the lesions, which show characteristic hyphae 6 .
Successful management of mucormycosis includes aggressive metabolic support, antifungal therapy with amphotericin B or posaconazole, and surgical debridement of all necrosis-involved tissue 2,3 ; the length of treatment is individualized, but is often 4-6 weeks long.There remains a need to achieve resolution of symptoms and confirm radiologic findings and negative cultures of the affected site 6 .

FIGURE 1 :
FIGURE 1: A. Contrast-enhanced radiography reveals a hypotonic stomach with excess fluid retention and difficulty in emptying (arrow).B. CT scan in the axial section without contrast demonstrating diffuse gastric distension associated with diffuse parietal thickening (arrow).CT: computed tomography.

FIGURE 2 :
FIGURE 2: Post-contrast CT scans.A. Venous phase in the sagittal section and B. late phase, demonstrating the stomach exhibiting inferior displacement of the thin intestinal loops and transverse colon.Diffuse gastric distension was associated with diffuse parietal thickening, which presented heterogeneous impregnation with contrast (arrow).CT: computed tomography.