A 70-year-old male presented for evaluation of fever and abdominal discomfort. Medical history was notable for acute myeloid leukemia in remission and hepatitis C complicated by cirrhosis and hepatocellular carcinoma, with sustained viral response with sofosbuvir and ribavirin and subsequent orthotopic liver transplant 7 years ago. He had a Klebsiella pneumoniae bacteremia with an associated liver abscess 2 years prior treated with oral ciprofloxacin. He was immunosuppressed with low dose tacrolimus monotherapy.
The patient had been experiencing intermittent fevers and night sweats increasing in frequency in the six weeks prior to presentation associated with persistent and progressive right upper quadrant pain, decreased appetite and 10 kg weight loss. He also described having a longstanding non-productive cough. Of note he had a history of travel to eastern Africa in the past; 4 years ago. He did not smoke, consume alcohol or recreational substances.
On initial evaluation, the patient appeared generally weak, but was in no acute distress, with a temperature of 38.3  C, blood pressure 170/70 mmHg, heart rate of 106 beats per minute, respiratory rate of 19 breaths per minute and saturating 99% on room air. His lungs were clear to auscultation bilaterally, with no murmurs or extra heart sounds noted on cardiovascular exam. Abdominal exam revealed right upper quadrant tenderness with negative Murphy's sign. The rest of his exam was unremarkable.
Complete blood count showed a white blood cell count of 8.8 x 109 /L (range 3.4-9.6 x109 /L) with normal differential, hemoglobin of 11.2 g/dL (range 13.2-16.6 g/dL) and platelet count of 161 x 109 /L (range 135-317 x109/L). Metabolic panel and liver chemistries were within reference limits. Right upper quadrant ultrasound revealed a 9 cm right hepatic lobe heterogenous mass. CT scan on the abdomen with intravenous contrast confirmed a 9 cm loculated hepatic abscess (Fig. 1). An ultrasound guided liver aspiration was done, and the patient was subsequently admitted to the medical floor. The patient was started on cefepime and vancomycin for broad spectrum antimicrobial coverage. The patient continued to spike fever 72 h after initiation of antibiotics. Liver aspirate culture showed growth of Mycobacterium conceptionense/houstonense/senegalense. After the positive growth on culture this was identified using MALDI TOF Mass Spectrometry. A liver MRI was done for pre-operative planning, and a left lung lower lobe opacity was noted. CT scan of the chest revealed a new 7 x 11 mm nodule (Fig. 2) along with other smaller, multiple nodules through both lungs with surrounding ground glass opacities. These nodules were deemed to be likely infectious in nature. Pulmonary tuberculosis was ruled out by 3 negative acid-fast bacilli smears, 2 negative mycobacterium tuberculosis PCR testing, and negative mycobacterial cultures. Further infectious workup, including serologic testing for endemic fungi, echinococcus, entamoeba and HIV was negative. The patient was subsequently taken to the operating room for right sided liver lobectomy. Acid fast bacilli staining of the tissue was focally positive for mycobacteria (Fig. 3). Tissue culture showed growth of the same organism. Susceptibilities are shown in Table 1. The patient was transitioned to intravenous amikacin, oral levofloxacin, and oral trimethoprim-sulfamethoxazole. Levofloxacin was later substituted for moxifloxacin due to nausea, with subsequent improvement of this symptom. His post-operative course was complicated by a bile leak, and subsequently had a biliary plastic stent place via ERCP. The patient continued to improve and was subsequently discharged. He had a follow up visit after completing 7 weeks of antibiotics, where his cough, fever and night sweats had improved, but continued to have poor appetite. Chest imaging showed improvement of the previously seen pulmonary nodules and CT of the abdomen showed improvement of bile leak. IV amikacin was discontinued with a plan to continue moxifloxacin and trimethoprim-sulfamethoxazole for 12 months completion. He continues to be followed closely in the outpatient setting.