It was thought that, following the discovery of antituberculous medications; tuberculosis will not pose any danger to humans. However, it is still of public health importance due to the challenges with diagnosis and treatment [5]. It mainly affects the respiratory system but may affect other organs. About 14% are extra pulmonary [6].
Tuberculous tenosynovitis is an uncommon but well-documented condition [7]. It normally affects the wrist and volar aspect of the hand and accounts for 5% of cases of osteoarticular tuberculosis [8]. The mechanism of the infection may be through hematogenous spread from a primary site in the lungs, lymph nodes, genitourinary or bones or by direct inoculation [1]. Precipitating factors include trauma, overuse of the joint, old age, low socioeconomic status, malnutrition, and immunosuppression [9]. The mechanism in our patient was not clear but we believe it was due to immunosuppression probably as a result of diabetes, and overuse of the wrist, as she is a farmer. Males are commonly affected and the right hand and wrist are mainly involved [10]. Our patient was female though the handedness conforms to what is commonly reported in the literature.
Patients normally present with an insidious, slow growing, sausage-shaped mass along the involved tendon with or without pain [9]. Some may present with carpal tunnel syndrome (as in our patient) or with discharging sinus. Because the onset is gradual, most people present with a well-advanced disease.
The disease progresses through 3 histopathological stages depending on the duration, resistance of the person, and virulence of the infecting pathogens [9]. In the initial stages, there is the replacement of the tendon by granulation tissue. Subsequently, the sheath is obliterated by fibrous tissue. This is followed by the appearance of rice or melon bodies as a result of caseation. The tendons, at the end, may consist only of a few strands of tissue leading to spontaneous rupture [9]. Rice or melon bodies were first described by Reise in 1895 [11] and consist of fibrinous masses (tubercles) and are believed to be due to micro-infarction following inflammation and ischemia of the synovial sheath and are present in about 50% of cases [7, 12]. According to a study by Woon et al. [13], the presence of rice bodies together with millet or melon seed shaped lesions are diagnostic of tuberculous tenosynovitis. For this reason, one should be aware of the importance of loose bodies when excising harmless-looking wrist and palmar lesions [13].
Diagnosis of tuberculous tenosynovitis is usually delayed due to the numerous differential diagnosis including other atypical mycobacterial infections, tuberculosis, systemic lupus erythematosus (SLE), pyogenic infections, brucellosis, foreign body tenosynovitis, osteoarthritis and rheumatoid arthritis [7, 12, 14,15,16,17]. Ultimately, diagnosis is by open biopsy and culture of the histopathological specimen. This however takes time and may delay the diagnosis and treatment. Hence when a provisional diagnosis of tuberculous tenosynovitis is made, it is imperative to start anti-tuberculous treatment while awaiting the result [4]. The recommended management especially when the condition is associated with clinical evidence of carpal tunnel syndrome is surgical (that is excision biopsy involving thorough curettage, lavage, and synovectomy) [18, 19] to decompress the median nerve. Local recurrence is possible and about 50% of cases recur within 1 year of treatment [20].
In conclusion, tuberculous tenosynovitis of the wrist is uncommon. However, in developing countries like Ghana where tuberculosis is common, tuberculous tenosynovitis should be considered among the possible causes of chronic tenosynovitis around the wrist. This is to prevent delay in diagnosis and treatment with its attendant complications. Excision biopsy and anti-tuberculous chemotherapy should be considered without delay when it is associated with established clinical signs and symptoms of carpal tunnel syndrome.