1 Background
1.1 Chemotherapy-Induced Bone Marrow Suppression
In 2020, among new cancer cases worldwide, breast cancer officially overtook lung cancer as the most prevalent form of cancer, accounting for 11.7% of all new cancer patients [1]. With continuous improvements in tumour treatments, there are now numerous therapeutic options for breast cancer. However, regardless of the chosen approach, chemotherapy still holds a prominent position [2]. Over several decades of development, chemotherapy drugs and regimens have continually advanced. Now, they play a crucial role in prolonging patient survival and enhancing their quality of life. However, various side effects from chemotherapy should not be underestimated, with bone marrow suppression being the most severe [3]. It mainly manifests as a reduction in red blood cells, white blood cells, and platelets. Consequently, conditions such as anaemia, infections, and bleeding may occur, resulting in adjustments, interruptions, or delays in chemotherapy. In severe cases, the patient’s life may even be endangered. Studies have suggested that the occurrence of bone marrow suppression is closely related to clinical factors such as the chemotherapy drug type, combined or sequential regimens, chemotherapy cycles, chemotherapy drug dosage and density [4], and even patient ethnicity [5].
1.2 Bacterial Pyogenic Liver Abscess
Pyogenic liver abscess is the most common infectious disease that affects the liver. The most prevalent form is bacterial pyogenic liver abscess, which is caused by invasive bacterial infections and accounts for approximately 80% of all pyogenic liver abscesses. In recent years in China and the Asia-Pacific region, there has been a gradual increase in pyogenic liver abscess cases caused by Klebsiella pneumoniae, which has replaced Escherichia coli as the primary pathogenic bacterium that causes bacterial pyogenic liver abscess [6,7]. Clinical manifestations of bacterial pyogenic liver abscess primarily include fever, chills, and, in some cases, right upper abdominal pain, nausea, vomiting, fatigue, weight loss, and jaundice. Clinical diagnosis relies on a combination of the patient’s symptoms, physical signs, inflammatory indicators such as blood routine, C-reactive protein, or procalcitonin, imaging examinations like abdominal ultrasound, CT, or MRI, as well as results from blood and puncture fluid bacterial cultures. Treatment options generally involve systemic anti-inflammatory therapy, ultrasound or CT-guided percutaneous drainage of the pyogenic liver abscess, and surgical intervention. Due to the potential for haematogenous dissemination in the early stages, Klebsiella pneumoniae pyogenic liver abscess (KPPLA) can easily lead to Klebsiella pneumoniae invasive syndrome, which often involves the lungs, central nervous system, and eyes [8,9].
1.3 Endogenous Endophthalmitis
Endogenous endophthalmitis (EE), also known as metastatic endophthalmitis, is a severe, vision-threatening intraocular infection caused by pathogenic bacteria in the bloodstream that penetrate the blood-ocular barrier and enter the intraocular environment. As the most serious complication of KPPLA, EE has an incidence rate of approximately 4.5% [10,11]. In its early stages, EE lacks distinct characteristic features, making initial diagnosis challenging and often leading to misdiagnosis. The progression of EE is rapid and the prognosis remains poor, even in cases that receive timely treatment [12]. Severe cases often lead to blindness and sometimes require enucleation of the eye. In this article, we review the clinical data of a patient who was admitted to our hospital with chemotherapy-induced bone marrow suppression combined with pyogenic liver abscess resulting in EE. A comprehensive analysis is provided based on the patient’s case and the relevant literature.