A 29-year-old man presented to the emergency department at Sultan Qaboos University Hospital (SQUH) with a 3-day history of fever, productive cough and shortness of breath. 10 days prior to current presentation, he had runny nose and tested positive for SARS-CoV-2 PCR from nasopharyngeal and throat swab.
His medical background comorbids include severe anti-neutrophil cytoplasmic antibody (ANCA) associated vasculitis (AAV) manifesting as pulmonary hemorrhage and biopsy proven necrotizing glomerulonephritis, as well as Hemophilia A.
His regular medications were amlodipine 10 mg once daily, carvedilol 6.25 mg twice daily, metformin XR 500 mg once daily, factor VIII replacement (2500 units) three times a week, prednisolone tapering dose and co-trimoxazole 480 mg once daily for PJP prophylaxis.
On physical examination he was alert and oriented but in moderate respiratory distress. His vitals were as follows: temperature 36, blood pressure 101/60 mmHg, heart rate 90 bpm, respiratory rate 26 bpm and oxygen saturation 93% on 6 liters of face mask oxygen (75% in room air). Chest auscultation revealed bilateral crackles. Other systematic examination was unremarkable.
Laboratory findings are presented in Table 1. Results of full blood count showed hemoglobin of 7.6 g which is at his baseline as well as normal platelets counts. However, He had neutrophilic leukocytosis, and his CRP was elevated at 122 mg/l. His coagulation profile showed isolated prolongation of APTT of 65.5 s, consistent with his hemophilia A. Renal parameters were remarkable for acute deterioration in comparison with his baseline (Baseline eGFR 40 s). His chest radiograph (not shown) showed bilateral air space opacities.
At this point he was admitted with impression of COVI-19 pneumonia. Patient was started on piperacillin-tazobactam at dose of 2.25 g IV every 8 h, azithromycin 500 mg PO once daily, dexamethasone 10 mg IV once daily along with esomeprazole 20 mg once daily.
During the same day of admission, the patient started having episodes of painless fresh bleeding per rectum estimated to be around 200 ml and hemoglobin dropped to 5.6 g/dl.In view of his background of hemophilia and difficulty in performing endoscopic evaluation due to his oxygen requirements, it was decided to manage him conservatively with packed red blood cell transfusions and factor VIII replacement, in liaison with the hematology team.
Despite daily factor VIII replacement, the lower GI bleeding persisted over the subsequent days. His oxygen requirements by then were minimal. Therefore, the gastro-enterology team was consulted for endoscopic evaluation of the colon. His colonoscopy showed a caecal circumscribed ulceration with central small polypoid lesion with no signs of active bleeding. The remaining segments of the colon were normal as shown in Fig. 1. Multiple biopsies were taken from the described lesions for histopathology evaluation. In view of ongoing lower GI bleeding requiring multiple blood transfusions, a Computed Tomography (CT) angiogram of the abdomen was also performed which showed evidence of a large ill-defined, eccentrically placed, heterogeneously enhancing soft tissue mass occupying the cecum. The mass extends across the serosal surface with multi-lobulated extra luminal component having broad area of contact with anterior peritoneum, concerning for malignancy. Fig. 2A, B.
During his hospital stay the patient's COVID-19 pneumonia recovered gradually and by the second week he was maintaining saturation of 94% and above in ambient air. However, fresh bleeding per rectum persisted, albeit smaller in volume, and his hemoglobin eventually stabilized at his baseline of 7 g/dl.
The caecal lesion histopathology report showed ulcerated colonic mucosa accompanied by fragments of granulation tissue and hemorrhagic necro-inflammatory debris. Several trophozoites of amoeba -were highlighted by PAS stain- within necrosis shown in Fig. 3. There was no dysplasia or malignancy. No fungi are demonstrated by GMS and PAS. Immunohistochemistry stain for CMV was negative. Entamoeba histolytica serology was sent. It came positive with IgG titer of 15.66 NovaTecUnits (NTU). Infectious Diseases team was consulted for the caecal ameboma and he was started on Intravenous metronidazole 750 mg every 8 h for total of 10 days. Patient's general status and rectal bleeding episodes improved after that course and his vitals stabilized. Therefore he was discharged to complete 21-day course of oral Metronidazole 800 mg every 8 h followed by cysticidal treatment with paromomycin for 7 days.
Our patient was seen in the outpatient clinic after 3 weeks from the discharge. He was doing well without any further episodes of lower GI bleeding. His follow up labs shown in Table 2 demonstrated stability of his blood counts, improvement in his inflammatory markers as well renal parameters. Follow up CT (Fig. 2 C, D) showed near-total interval resolution of previously visualized exophytic caecal mass as well as significant interval resolution of previously visualized ill-defined eccentric heterogeneously enhancing soft tissue caecal wall thickening. Follow up colonoscopy was done (images not shown) and showed distal caecal annular ulcer of 3 cm length by 1 cm width which was biopsied for histopathological evaluation, mycobacterial tuberculosis, and cytomegalovirus evaluation. The follow up histopathology report (Fig. 4) showed no residual amoeba histolytica trophozoites and unremarkable for any other pathogens.