Successful Treatment of Mucormycosis Endocarditis Complicated by Pulmonary Involvement

Case Report

We present a 37-year-old male patient with a history of ulcerative colitis treated with corticosteroids and mesalazin due to exacerbation of his underlying condition. The patient was admitted to the hospital since there was no improvement of his clinical status. A central venous catheter was inserted via the right internal jugular vein for administration of intravenous antibiotic therapy, which included ciprofloxacin and metronidazol, as well as corticosteroids. The same catheter was employed for total parenteral nutrition.

His hospital course was complicated with fever followed by septic shock. As line sepsis was suspected, the jugular catheter was promptly removed. The patient's deteriorating clinical condition required him to be transferred to the intensive care unit. His initial management included volume resuscitation and vasoactive support with dopamine. His antibiotics were changed to tazobactam/piperacillin and vancomycin. His white cell count was 6.8 × 10⁹/L and his C-reactive protein (CRP) was 164 mg/L.

The blood cultures grew vancomycin-sensitive Enteroccocus faecium and Candida parapsilosis. This prompted inclusion of liposomal amphotericin B at 0.5 mg/kg into the management protocol. After four days of targeted antibiotic treatment, the patient was hemodynamically stable, but his fever persisted as did the elevation of his acute phase markers. A transthoracic echocardiogram revealed a 6 × 1.8 cm right atrial mass ([Fig. 1 a]). These findings were corroborated by transesophageal echocardiography ([Fig. 1 b]).

Fig. 1 a and b Echocardiographic image of the giant right atrial mass (vegetation) protruding across the tricuspid valve during diastole into the right ventricle. a Transthoracic apical four-chamber view, b transesophageal four-chamber view (RA: right atrium, RV: right ventricle, TV: tricuspid valve, LA: left atrium, LV: left ventricle).

The patient was then referred for cardiac surgery. Intraoperatively, the tumor was found to be attached to the lateral wall of the right atrium. The intracardiac mass was excised via a right atrial approach with the aid of tepid cardiopulmonary bypass. There was no obvious infiltration of the surrounding structures. The patient was weaned off cardiopulmonary bypass uneventfully. The histological analysis revealed mycotic hyphae and spores ([Fig. 2]). The microbiology of the operative specimen was positive for Mucor species and Enterococcus faecium.

Fig. 2 Pathophysiology of atrial endocardial vegetation showing hyphae of mucormycosis, stained with hemalaun-eosin, × 400.

The early postoperative course was unremarkable, save for the development of multiple nodal lesions on the patient's chest X‐ray. Computed tomography (CT) of the chest showed multiple nodal lesions up to 1.4 cm in diameter in close proximity to the blood vessels, some of which were exhibiting a region of central necrosis. Bronchoscopy was then performed. The bronchoalveolar lavage (BAL) specimen was negative for mucormycosis. The CRP level remained high two weeks after surgery.

Although BAL was negative for mucormycosis, we suspected that hematogenous spread of mucormycosis to the lungs had occurred. We, therefore, increased the liposomal amphotericin B dose to 5 mg/kg. The goal was to give a total dose of 15 000 mg of liposomal amphotericin B.

The patient responded well and clinical improvement was obvious. At the time, ulcerative colitis was in remission and allowed us to gradually terminate the corticosteroid therapy.

When the targeted dose of 15 000 mg of liposomal amphotericin B was reached, the CRP level was still slightly above normal (CRP 32 mg/L). We, therefore, decided to give our patient another 3000 mg of liposomal amphotericin B, after which the CRP level was within normal limits.

A follow-up chest CT showed improvement but not total regression of the nodal lesions. At the time, the patient was afebrile and feeling well. Liposomal amphotericin B therapy was then discontinued.

A repeat chest CT scan one month later has remained unchanged. A repeat BAL and transbronchial biopsy of the lung lesions revealed no evidence of mucormycosis.

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