We present the case of a 44-year-old Portuguese man with pulmonary tuberculosis diagnosed two years earlier and treated accordingly for 6 months, and also a history of chronic alcohol-related pancreatitis with pancreatic insufficiency and insulin-dependent diabetes. His medication was Lantus  insulin. Family history was not relevant and there was no other drug use, travelling history or animal contact reported.
The patient presented to the emergency department with a 2-week history of fever (39 oC), dry cough, mucoid rhinorrhea and cervicalgia. Physical examination showed normal mental status and slight dehydration. He was eupneic while breathing room air, SpO2 95%, with no signs of breathing difficulty; normotensive, BP 106/93 mmHg, HR 97 bpm; and febrile (tympanic temperature of 38 oC). Cardiopulmonary auscultation revealed bilateral basal crackles. His abdomen was soft with palpable hepatomegaly. An intense cervicalgia was evident with painful palpation of C4 and C5 spinous processes causing immobilization. There were no neurologic findings on examination.
Laboratory tests showed normocytic normochromic anemia (Hb 13.0 g/dL, MCV 86 fL), raised inflammatory markers (20,600/muL leukocytes, relative neutrophilia (89.9%) and C-reactive protein 20.24 mg/dL), hyperglycemia (301 mg/dL), normal renal and hepatic markers, raised LDH (288 UI/L) and hyponatremia (125 mmol/L).
Chest radiography revealed numerous bilateral nodular hypotransparencies, as well as cavitation on the right middle lobe. Cervical radiography was normal. Community-acquired pneumonia was diagnosed and empiric antimicrobial therapy with amoxicillin/clavulanic acid and azithromycin was started after blood cultures withdrawn. The patient was then admitted to an internal medicine ward.
Diagnostic work-up included several complementary tests summarized in Table 1. A thoracic CT scan showed multiple pulmonary nodular lesions suggestive of metastases. It also identified a juxtapleural nodular condensation on the right lower lobe with spiculated margins and eccentric cavitation, acknowledged as the probable primary tumor. Appreciation of the subdiaphragmatic segments also revealed multiple nodular hypodense liver lesions suggestive of metastatic malignancy with a confluent pattern (Fig. 1). Given the persistence of refractory cervicalgia, a cervical MRI was performed, which suggested secondary epidural infiltration (Fig. 2).
Imaging findings appeared unequivocal, suggesting cancer of unknown primary origin (probable lung) with pulmonary, hepatic and epidural secondary involvement. Nevertheless, the patient's previous history prompted the exclusion of pulmonary tuberculosis. Bronchofibroscopy revealed diffuse inflammatory signs along the mucosa with no evidence of cancer cells or acid-alcohol resistant bacilli (AARB). An abdominal and pelvic CT scan was performed, showing multiple focal hypodense lesions with fluid collections and a peripheral nodular enhancement pattern, typical tomodensitometric findings of liver abscesses (Fig. 3).
The patient remained on empiric antimicrobial treatment and, within a few days, his fever resolved, his cervicalgia significantly improved, and inflammatory biomarkers continuously decreased. Four weeks after admission, following discussion with Radiology, a thoracic CT scan was performed for subsequent biopsy of one of the pulmonary lesions. However, tomographic re-evaluation showed undeniable reduction in the number and volume of pulmonary nodules, with stability of the liver abscesses (Fig. 4). In light of these findings, a biopsy was not performed.
This tomographic evolution thus revealed the true inflammatory/infectious nature of those pulmonary lesions, contradicting the initial hypothesis. Concurrently, the blood cultures withdrawn at admission became positive for K. pneumoniae, also isolated in bronchoalveolar lavage. Considering the clinical evolution and the microbiological isolates, a diagnosis of K. pneumoniae primary liver abscess with metastatic infection - best known in the literature as Klebsiella pneumoniae invasive syndrome - was made. As expected, the antibiotic susceptibility test proved the strain to be sensitive to most antibiotics (Table 2). Hence, azithromycin was stopped, while amoxicillin/clavulanic acid were continued. The patient continued to improve under antimicrobial therapy and was discharged after 6 weeks of treatment. Follow-up imaging studies showed outstanding improvement.
Thoracic CT: 4th-week follow-up with unequivocal reduction in both number and volume of nodular pulmonary lesions.