Left Middle Phalanx Tuberculous Dactylitis Masquerading as a Tumor: First Case Report in Saudi Arabia.

Tuberculous dactylitis can cause osteomyelitis, which is a rare extrapulmonary manifestation of tuberculosis, often misdiagnosed due to its nonspecific presentation and resemblance to other conditions like neoplasms. A 15-year-old male patient reported to our clinic with a 1-year history of left index finger pain and swelling following a football-related injury. Despite conservative management, the symptoms had progressively worsened over the past few months. Clinical examination revealed deformity and swelling of the middle phalanx, along with induced pain on range of motion. Bacteriological analysis indicated polymorphic nuclear cells and the presence of coagulase-negative Staphylococcus (Staphylococcus hominis). Radiographic evaluation, including x-ray and magnetic resonance imaging, revealed medullary expansion, trabecular thinning, and focal soft tissue swelling. Magnetic resonance imaging displayed extensive soft tissue and bone marrow involvement, raising concerns of a tumor. An open biopsy was performed, yielding unexpected findings of necrotizing and suppurative granulomatous inflammation, strongly suggesting an ongoing infectious process. The subsequent Quantiferon TB Gold Test confirmed tuberculosis infection. Treatment encompassed debridement, synovectomy, and initiation of an antituberculosis regimen. The patient showed significant improvement after treatment. Timely diagnosis and treatment of tuberculous dactylitis are crucial, as highlighted by the patient's positive response to combined surgical and pharmacological intervention, despite initial diagnostic challenges.