Rare Case of Tibial Diaphyseal Tuberculosis in Sickle Cell Anemia: A Clinical Report

A medical case report has highlighted a rare occurrence of tuberculous diaphyseal osteitis in the tibia of a patient with sickle cell anemia SS. The report describes the diagnostic challenges and the clinical presentation of this uncommon manifestation of extrapulmonary tuberculosis.

The case involved a 26-year-old female patient diagnosed with sickle cell anemia SS. The patient presented with physical swelling located in the middle third of the left leg.

Laboratory evaluations revealed that the patient was experiencing a systemic inflammatory response syndrome. Imaging tests further identified endomedullary osteolytic lesions within the tibial diaphysis, which are areas of bone destruction inside the shaft of the tibia.

Understanding Diaphyseal Tuberculosis

Tuberculosis is primarily known as a pulmonary infection caused by Mycobacterium tuberculosis, but it can spread to other parts of the body, resulting in extrapulmonary tuberculosis. Skeletal tuberculosis is a form of this spread, where the bacteria infect the bones or joints.

While skeletal tuberculosis is relatively well-documented, it most frequently affects the spine—a condition known as Pott’s disease—or the large joints. Tuberculosis that specifically affects the diaphysis, or the shaft of a long bone, is considered rare, particularly in adult patients.

The diagnosis of tuberculous diaphyseal osteitis often requires a combination of clinical examination, advanced imaging and pathological examination to distinguish it from other bone infections or tumors.

The Role of Sickle Cell Anemia

The patient’s underlying condition, sickle cell anemia SS, is a significant factor in the development of such infections. Sickle cell disease is a genetic blood disorder that affects hemoglobin, the protein in red blood cells that carries oxygen.

Patients with sickle cell anemia SS often experience a higher susceptibility to various infections due to several physiological factors:

• Splenic dysfunction: Many patients undergo a process of autosplenectomy, where the spleen becomes scarred and non-functional over time, reducing the body’s ability to filter bacteria from the blood.
• Immune compromise: The disorder can impair the function of white blood cells and other components of the immune system.
• Vaso-occlusive crises: The “sickling” of red blood cells can block blood flow to tissues and organs, potentially creating environments where infections can more easily establish themselves.

These factors make individuals with sickle cell anemia more vulnerable to both typical bacterial infections and atypical infections, including mycobacterial diseases like tuberculosis.

Clinical Implications and Diagnosis

The presentation of swelling and osteolytic lesions in the long bones of immunocompromised patients can mimic other conditions, such as chronic osteomyelitis or bone tumors. This overlap makes the differential diagnosis critical for ensuring the patient receives the correct treatment.

In this specific case, the combination of the patient’s systemic inflammatory response and the specific location of the lesions in the tibial diaphysis led to the conclusion of tuberculous diaphyseal osteitis following pathological examination.

Medical literature emphasizes that in patients with compromised immune systems, clinicians should maintain a high index of suspicion for extrapulmonary tuberculosis when presented with atypical bone lesions, even in the absence of classic respiratory symptoms.