A fifty-seven-year-old male patient without previous history of heart disease presented to the hospital with worsening shortness of breath since one week before admission. He also complained of fever and weight loss for three months. Additionally, he also experienced back pain along with lower limb weakness for a month. The patient was diagnosed with pneumonia and was treated with moxifloxacin. His sputum examinations were sterile and negative for acid-fast bacilli staining and GeneXpert MTB/RIF. After one week of antibiotic therapy, at the day of illness (DOI)-14, there is no noticeably clinical improvement. The patient was then referred to the cardiology department and underwent transthoracic echocardiography (TTE), in which a large oscillating mass at the posterior mitral leaflet (PML) was detected. The patient was diagnosed with infective endocarditis (IE) and given Ampicillin/Sulbactam and Gentamycin. Three consecutive blood cultures were negative. On the third week of hospitalization (DOI-28), the patient's condition did not improve, and he was referred to our hospital.
Upon our hospital admission (DOI-30), the patient looked lethargic; the blood pressure was 100/60 mmHg, with a heart rate of 88 bpm, respiratory rate of 30 times per minute, and the temperature was 36.8  C. Physical examination showed an enlarged heart with a 3/6 pansystolic murmur at the apex with paraparesis and paresthesia of the lower limb at the level of L3. However, no gibbous was observed on spine examination.
The laboratory results showed a hemoglobin of 9.2 gr/dl, leukocytes of 15,230/mm3 with increased C-reactive protein (CRP) (6.01 mg/dL), and procalcitonin (10.20 ng/ml) level, and positive rheumatoid factor. The electrocardiogram showed left ventricular hypertrophy with first-degree AV block. The echocardiography evaluation revealed mitral regurgitation (MR) with ruptured chordae tendineae, perforated leaflet, and multiple vegetation attached to both leaflets (Fig. 1). Magnetic resonance imaging (MRI) for the spine revealed multiple small abscesses at L2-3, L5-S1 (Fig. 2). The patient was diagnosed with blood culture-negative infective endocarditis (BCNIE) and spondylodiscitis due to pyogenic infections. We resumed the antibiotic, performed blood culture assessments, and planned for early surgery. However, the subsequent five consecutive blood cultures were negative for aerobic, anaerobic, and fungal blood cultures. A multidisciplinary clinical meeting was performed, and it was decided that the patient would undergo discectomy first, followed by cardiac surgery afterward.
An open discectomy was performed three weeks after admission to our hospital (DOI-48). Granuloma tissue was found without purulent or abscess tissue. Debridement and irrigation were conducted. The pathologic examination of the spinal tissue showed proliferation of epithelioid cells with multinucleated datia Langhans (Fig. 3a and b). Although these findings suggest tuberculous infection, the GeneXpert MTB/RIF test was negative.
Cardiac surgery was performed one week later (DOI-57). The surgery was performed with the left atrial approach. Multiple vegetation in the anterior mitral leaflet (AML) and PML (Fig. 4) were detected. The mitral valve was replaced with a mechanical prosthetic valve. During the postoperative period, rebleeding occurred in the intensive care unit. We planned to perform a redo surgery; however, the patient's family refused, and the patient passed away.
The pathologic examination of mitral valve tissue showed proliferation of epithelioid cells with caseous necrosis area and multinucleated datia Langhans (Fig. 3c and d). The vegetation was cultured and showed no bacterial, MTB, or fungal growth. The smear for Acid Fast Bacilli and GeneXpert MTB/RIF were also negative. The real-time polymerase chain reaction (RT-PCR) consisted of IS6110, an insertion gene corresponding to the detection of MTB complex, which was performed on the vegetation tissue. The RT-PCR result showed amplification for IS6110 and was confirmed with the pyrosequencing method. The summary of patient history can be seen in Fig. 5.