Tuberculosis of the triceps muscle

Area of Science:

• Orthopedic Surgery
• Infectious Diseases
• Radiology

Background:

• Skeletal muscle tuberculosis is rare, particularly in immunocompetent individuals.
• The triceps muscle is an unusual site for tuberculous infection.
• Diagnosis often requires advanced imaging and microbiological confirmation.

Observation:

• A 25-year-old immunocompetent male presented with a hard, fixed swelling at the lower end of his triceps muscle.
• The swelling was initially suspected to be a neoplastic or other inflammatory condition.

Findings:

• Fine-needle aspiration cytology (FNAC) of the triceps swelling was performed for diagnostic evaluation.
• Polymerase chain reaction (PCR) testing on the FNAC specimen confirmed the presence of Mycobacterium tuberculosis.
• Histopathological examination further supported the diagnosis of tuberculous myositis.

Implications:

• This case highlights the importance of considering extra-pulmonary tuberculosis in the differential diagnosis of localized muscle swellings, even in immunocompetent patients.
• Early and accurate diagnosis using FNAC and PCR is crucial for effective management.
• Prompt initiation of antitubercular therapy led to a complete resolution of symptoms and a favorable patient outcome.