Tuberculous extensor tenosynovitis of the wrist in a patient with systemic lupus erythematosus mimicking a giant cell tumour: A case report and review of literature

Abstract

Introduction & importance

Extrapulmonary tuberculous involvement of the musculoskeletal system is not common and seen in less than 10 % of all cases. The bidirectional association between tuberculous infection of the musculoskeletal system and rheumatological diseases has been widely recognized and arises both as a result their underlying immunosuppressive state and of drug induced immunosuppression.

Case presentation

A 45-year-old female on treatment for SLE, in remission, presented with a slow growing mass over the dorsum of the right wrist with functional impairment which was clinically and radiologically compatible with a giant cell tumour. Pathological examination after surgical excision revealed pathognomonic features of tuberculous tenosynovitis. Multidrug antituberculous therapy was commenced.

Clinical discussion

Clinical diagnosis of tuberculous tenosynovitis is difficult due to the non-specific clinical symptoms and signs. Laboratory investigations are usually normal except for ESR which may be elevated. Delay in establishing therapy may lead to dissemination of mycobacteria to the surrounding bursae, muscles and soft tissue leading to joint and tendon damage. Detection of mycobacteria through TB culture and microscopy of the specimen has a low sensitivity and therefore treatment should be promptly initiated when typical pathological findings are seen.

Conclusion

Tuberculous tenosynovitis of the extensor tendons is a rare clinical presentation and must be suspected in cases of chronic and recurrent tendon sheath infection especially in an immunocompromised patient in a TB endemic country. The lack of clinical suspicion, nonspecific findings and mimicry of other conditions can lead to delayed diagnosis and complications.

Highlights

• •The immunological derangements and use of immunosuppressive medication in diseases such as SLE, contribute to a higher prevalence of pulmonary and extrapulmonary TB.
• •Primary tuberculous tenosynovitis is rare accounting for 5% of osteoarticular TB.
• •Tuberculous tenosynovitis must be suspected in cases of chronic and recurrent tendon sheath infection.
• •Clinical diagnosis is difficult due to the non-specific clinical signs shared with other infective, inflammatory and neoplastic conditions affecting the synovium.
• •Definitive diagnosis of tuberculous tenosynovitis depends on histopathological examination and bacteriological confirmation

1. Introduction

Tuberculosis (TB) is an endemic infection in Sri Lanka with low prevalence rates [1,2]. Extrapulmonary tuberculous involvement of the musculoskeletal system is not common and seen in less than 10 % of all cases. Its manifestations include involvement of the bone, joints, muscles, bursae and tendon sheaths [3]. It occurs as a result of direct inoculation or haematogenous spread from other primary sites such as the lungs, spine or lymph nodes [4].

The bidirectional association between tuberculous infection of the musculoskeletal system and rheumatological diseases has been widely recognized and arises both as a result their underlying immunosuppressive state and of drug induced immunosuppression [3]. High incidence of TB has been reported in patients with systemic lupus erythematosus (SLE) with increased incidence of extrapulmonary forms with high mortality rates, especially in developing countries where TB is endemic [5].

Fist described by Acrel in 1756, mycobacterial involvement of tendon sheaths is rare and causes chronic inflammation of the tendon sheaths and hence must be suspected in cases of chronic and recurrent tendon sheath infection [[4], [5], [6], [7], [8]]. Involvement of tendon sheaths of the hand and wrist is more commonly seen than in the foot or ankle, and flexor tendons are involved more commonly than extensor tendons [7]. The lack of clinical suspicion, nonspecific findings and mimicry of other conditions usually leads to diagnostic delays, which are associated with complications such as tendon rupture [6].

This is a case of a patient with SLE presenting with a non-specific swelling of the wrist suspicious of neoplastic aetiology, but later found to have tuberculous tenosynovitis. This case has been reported in line with SCARE criteria [9].

2. Case presentation

A 45-year-old Sri Lankan female walked into the orthopaedic clinic of a tertiary care hospital with a gradual onset, progressively increasing, painful swelling over the dorsum of the right wrist of her dominant hand for two years. The pain was dull and aching in nature, worsened with movement of the wrist but without nocturnal exacerbation. Extension of the wrist and middle and ring fingers was impaired affecting her activities of daily living and occupation related teaching activities. She was constitutionally well, with no history of trauma or active joint symptoms.

Physical examination revealed a 6x3cm diffuse swelling over the dorsum of the right wrist extending proximally from the wrist, which was firm, smooth, not-fluctuant nor trans -illuminant, with ill-defined boundaries. It was mobile in the transverse direction with limited mobility along the longitudinal direction. The overlying skin appeared normal. Wrist extension was impaired with finger drop noted in the middle and ring fingers.

Back in 1996, she was evaluated for prolonged fever with cervical lymphadenopathy, constitutional symptoms, a malar rash and small joint arthralgia of the hand. Excision biopsy of the lymph node confirmed histiocytic necrotizing lymphadenitis (Kikuchi-Fujimoto disease). She was screened for and diagnosed with systemic lupus erythematosus based on clinical and immunological criteria and has been under follow up for the past 25 years. In 2020, she had a positive contact history with a first degree relative who succumbed to pulmonary tuberculosis. She is currently only on hydroxychloroquine (HCQ).

Laboratory investigations including full blood count and erythrocyte sedimentation rate (ESR) were normal. Radiographs showed no bone or joint abnormalities. MRI of the right wrist showed a peritendinous lesion encircling the extensor tendons extending proximally from the carpometacarpal junction without evidence of local infiltration but with mild pressure effects. This appearance was suspicious of a giant cell tumour (Fig. 1).

Fig. 1.

A, B - MRI of the right wrist showed a peritendinous, T1 low and T2 heterogenous signal intensity lesion encircling the extensor tendons extending 6 cm proximal from the carpometacarpal junction, measuring 6 (longitudinal) × 3.2 (transverse) × 1.1 cm (thickness), with peripheral enhancement post contrast and mild pressure effects on the adjacent soft tissue without evidence of infiltration. The tendons and underlying bones appeared normal.

The patient underwent surgical excision of the lump under general anaesthesia under an avascular field using a pneumatic tourniquet with the arm abducted to 90 degrees and placed in pronation on an operating table by the orthopaedic surgeon. Exposure through a dorsal incision made over the lump, revealed a complex tumour arising from the synovial membrane of the extensor tendons. The tendons were separated from the synovium and tumour excised. Part of the extensor tendon to the index finger was sacrificed. Routine closure was performed and a below elbow splint applied for 4 weeks, with occupational therapy initiated in the interim (Fig. 2).

Fig. 2.

Synovial tissue mass with multiple rice bodies.

Pathological evaluation revealed synovial tissue with dense granulomatous inflammation with epithelioid histiocytes, Langhan type multinucleate giant cells and foci of caseous necrosis with numerous rice bodies highly suggestive of tuberculous synovitis. Ziehl Neelsen staining was performed and negative for acid fast bacilli. There was no evidence of a neoplasm. Since tuberculous tenosynovitis was not suspected preoperatively, a sample was not sent for TB culture and PCR (Fig. 3).

Fig. 3.

H&E staining showing granulomatous inflammation with epithelioid histiocytes, Langhan type multinucleate giant cells and foci of caseous necrosis with numerous rice bodies.

The patient was referred to the chest physicians as per health policy and was commenced on multidrug anti-tuberculous therapy with Isoniazid, Rifampicin, Pyrazinamide and Ethambutol for 2 months duration with planned continuation of Isoniazid and Rifampicin for a further 10 months. She is under follow up at both clinics, has no functional impairment and had no evidence of recurrence at 3 months.

3. Discussion

Extrapulmonary tuberculosis of the musculoskeletal system is rare and accounts for less than 10 % of all cases of tuberculosis [6]. Direct musculoskeletal involvement of mycobacteria can affect the spine, joints, bone, muscles and tendon sheath, manifesting as spondylitis, septic arthritis, osteomyelitis, myositis, subcutaneous abscesses and tenosynovitis [3].

Primary tuberculous tenosynovitis is much rarer accounting for 5 % of osteoarticular TB. It is more commonly seen to involve the right hand and wrist and is more common in men. The flexor tendons and radioulnar bursae over the hand and wrist are the usual sites of involvement, although it has been described in the extensor wrist tendons as well. Multifocal synovitis too has been reported [6]. In this case, there was primary tuberculous involvement of the synovium of the extensor tendons of the right wrist in a middle-aged female, without involvement of the adjacent wrist joint.

Its pathogenesis has been attributed to direct inoculation of mycobacteria from adjacent bone or joint infection or haematogenous spread from pulmonary or genitourinary tuberculosis [6]. In Sri Lanka, where TB is endemic, reactivation of latent tuberculosis was the likely reason. However primary TB is also possible, due to her susceptibility to altered immune regulation [10]. Malnutrition, immunosuppression, alcoholism, advanced age, poor socioeconomic status are patient-related risk factors for the development of tuberculous tenosynovitis. Joint overuse, local steroid injection and trauma are additional risk factors [6,7]. This patient had no evidence of pulmonary TB or other forms of extrapulmonary TB and adjacent wrist joint and bones were normal. She had no local risk factors. The relative immunosuppressive state due to SLE and the use of HCQ were the only identifiable risk factors.

The immunological derangements seen in autoimmune rheumatological diseases such as SLE, and use of immunosuppressive medication, contribute to higher prevalence of TB infection, higher rates of extrapulmonary TB and higher rates of morbidity and mortality associated with TB, in patients with SLE [10,11].

Clinical diagnosis of tuberculous tenosynovitis is difficult due to the non-specific clinical signs. The usual clinical presentation is with a slow-growing, sausage shaped swelling of the tendon sheaths associated with pain, tumour mass, abscess, restricted range of motion and carpal tunnel syndrome [6,11]. Synovitis associated with infections with other mycobacteria, pyogenic infections, brucellosis and inflammatory condition like rheumatoid arthritis, gout and sarcoidosis can present in similar manner [6,7]. Laboratory investigations are usually normal except for ESR which may be elevated [6]. Concurrent pulmonary or intrathoracic TB is seen in in less than 50 % of patients with extrapulmonary TB, hence chest radiographs are usually normal [3,12]. Mantoux tests are falsely negative in the presence of immunosuppressive states [3]. This patient had a localized swelling over the dorsum of the wrist with functional impairment and all other investigations were normal.

Mycobacterial infection induces a state of chronic inflammation of the tendon sheath. Initially the tendon is replaced by vascular granulation tissue, the sheath is obliterated with fibrous tissue and fluid may be seen within the synovial sheath. Rice bodies or Melon seeds which represent fibrinous masses are seen in 50 % of cases. In late stages, the tendon may contain only a few strands of fibrous tissue resulting in spontaneous tendon rupture [6]. Delay in establishing therapy may lead to dissemination of mycobacteria to the surrounding bursae, muscles and soft tissue leading to joint and tendon damage [12]. Although there was a two-year history in this presentation, there was no evidence of tendon rupture or wrist joint extension.

Definitive diagnosis of tuberculous tenosynovitis depends on histopathological examination and bacteriological confirmation. Detection of mycobacteria through TB culture and microscopy of the specimen has a low sensitivity of 20–40 % and therefore treatment should be promptly initiated when typical pathological findings of chronic inflammation with rice bodies and caseous necrosis are seen [11]. Although she had a positive contact history for tuberculosis, there was no clinical suspicion of tuberculous synovitis at the onset. Backed by the MRI appearance consistent with a giant cell tumour, workup and surgery was planned for enbloc resection of the tumour. Hence samples were only sent for pathological evaluation and not for TB culture nor gene assays. Although Ziehl Neelsen staining did not reveal acid fast bacilli, the pathognomonic features of tuberculous synovitis which include granulomatous inflammation with epithelioid histiocytes, Langhan type multinucleate giant cells and foci of caseous necrosis with numerous rice bodies were all seen in the specimen and adequate to make a pathological diagnosis.

There is no consensus on the optimal treatment of tuberculous tenosynovitis. Some authors recommend surgery alone, some surgery with chemotherapy, and some chemotherapy alone. The choice of surgery also ranges from decompression of the tendon sheath to debridement and tendon sheath excision [7]. Surgical debridement with synovectomy followed by multidrug anti-tuberculous chemotherapy for 6–9 months is the recommended treatment for tuberculous tenosynovitis [11,13]. Although functional outcomes are good, local recurrences is seen in up to 50 % of patients at one year and close follow up is necessary as a result [4,13].

This middle-aged female with cutaneous SLE in remission, on HCQ presented with a wrist swelling suspicious of a giant cell tumour both clinically and radiologically. She underwent surgical excision and lesion showed histology compatible with tuberculous tenosynovitis. She was started on multidrug antituberculous therapy and shows good functional outcome with no recurrence at 3 months.

4. Conclusion

Although extrapulmonary TB is common in patients with SLE, tuberculous tenosynovitis of the extensor tendons is a rare clinical presentation and must be suspected in cases of chronic and recurrent tendon sheath infection especially in a TB endemic country. The lack of clinical suspicion, nonspecific findings and mimicry of other conditions can lead to delayed diagnosis and complications.

Informed consent

Written informed consent was obtained from the patient for their anonymized information to be published in this article.

Patient perspective

The patient was glad to note that the aetiology was tuberculous and not neoplastic. Although the long duration of therapy is cumbersome, she vows to exercise good compliance.

Ethical approval

Our institution does not require ethical approval for reporting individual cases or case series.

Funding

This research received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors.

Guarantor

Deshan Gomez.

Research registration number

• 1.Name of the registry: N/A
• 2.Unique identifying number or registration ID: N/A
• 3.Hyperlink to your specific registration (must be publicly accessible and will be checked): N/A.

CRediT authorship contribution statement

Deshan Gomez: Conceptualization, Writing – original draft, Writing – review & editing, Visualization. Sampath Marasinghe: Writing – review & editing. Kanapathipillai Umapathy: Supervision, Writing – review & editing.

Declaration of competing interest

The authors declare that there is no conflict of interest.